AIDOTOOL
Handy online tools for work and life
Runs in your browser2 Languages10 Themes
Recommended
Editor's PickGrid SplitterCut one image into 4, 9, 16 or 25 cells and replace any cell with a different image; lay a heart, star, hexagon, stamp or flower mask over the whole grid with a transparent or custom outside colour, then export a cell, the whole image or a ZIP — all local, nothing uploaded.NEWImage to PDFMerge photos, screenshots and scans into one PDF locally: drag-sort and rotate images, A4 to B5 or adaptive page sizes, contain / cover / stretch / original-size fit, lossless JPG and PNG embedding, grid layouts, page numbers and headers, tall-image splitting, paginated preview and Blob export — nothing is uploaded.Spin Wheel PickerPaste a list into the wheel, let the weights size the sectors and the pointer decide: the winner is drawn with cryptographic randomness first and the angle is solved backwards, then verified against the pointer once the wheel stops. Sector images and colors, multiple pools, no-replacement draws, win history and stats, sound, confetti and a fullscreen stage, all stored locally.Image CompressorCompress JPG, PNG, WebP and AVIF images locally in your browser: by quality, by target file size (automatic binary search), by dimensions or a mix of both, with batch processing, format conversion, alpha handling, before/after comparison and ZIP download.Markdown PreviewWrite Markdown on the left and render it live on the right, with GFM tables, fenced code blocks and strikethrough, plus a view and one-click copy of the generated HTML source.QR Code GeneratorGenerate a QR code from any text, link or phone number, with adjustable size, margin, error-correction level and foreground or background colors, live preview and one-click HD PNG download.Learn to Tell TimeA beautiful teaching clock for kids: explore the dial and hands, set any time with sliders, then practice o’clock, half-past, 5-minute and any-time quizzes.English Case Converter — 12 Naming StylesConvert any English text into 12 naming styles at once: UPPER, lower, Title Case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, alternating, swap case and text reverse, with live character count and one-click copy.Focus Timer — Deep Work CountdownA clean focus timer for deep work: pick a 25 / 45 / 90 minute session (or set your own), press start and work without distractions. The ring shows progress, sessions that finish are recorded in your local history, and a gentle tone lets you know the session is over.
Latest Tools
10 New This WeekDice RollerRoll 1 to 9 3D dice at once, 3 by default; cryptographic randomness picks the faces before the tumble, with clacks, per-die values, sum stats and the last ten rolls.NEWBatch RenameRename files locally in bulk: pick a folder (read-only) or a batch of files, preview the result through normalization, find-and-replace, filtering, case, prefix/suffix, numbering and extension, then export a ZIP copy or a rename manifest. Files are not uploaded and not changed — download to take effect.NEWImage PreviewOpen many images at once in your browser: JPG, JPEG, PNG, WebP, GIF, BMP, ICO, SVG, AVIF, HEIC and TIFF. Previous and Next navigation, reset, rotate, zoom in and out, fit to window, flip, full screen and a thumbnail strip, plus page-by-page browsing for multi-page TIFF, keyboard and wheel controls — nothing is uploaded.NEWWebP to JPGBatch-convert WebP images into widely supported JPG locally in your browser: adjustable quality and transparency fill, orientation correction, a batch list, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; nothing uploaded.NEWWebP to PNGSave WebP images losslessly as PNG: every decoded pixel and the alpha channel are preserved, making the result ideal for further editing, cut-outs and long-term archiving, with a batch list, orientation correction, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; all local, nothing uploaded.NEWAVIF to JPGBatch-convert AVIF images into widely supported JPG locally in your browser: adjustable quality and transparency fill, orientation correction, a batch list, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; nothing uploaded.NEWAVIF to PNGSave AVIF images losslessly as PNG: every decoded pixel and the alpha channel are preserved, making the result ideal for further editing, cut-outs and long-term archiving, with a batch list, orientation correction, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; all local, nothing uploaded.NEWAVIF to WebPTurn AVIF photos into web-friendly WebP: keeps transparency, offers an adjustable quality slider and a live before-and-after size comparison, with batch handling, Previous and Next preview, single downloads and a ZIP — decoded locally, nothing uploaded.NEWGrid SplitterCut one image into 4, 9, 16 or 25 cells and replace any cell with a different image; lay a heart, star, hexagon, stamp or flower mask over the whole grid with a transparent or custom outside colour, then export a cell, the whole image or a ZIP — all local, nothing uploaded.NEWHEIC to JPGBatch-convert iPhone HEIC and HEIF photos to JPG locally in your browser: adjustable quality and transparency fill, orientation correction, a batch list, Previous and Next side-by-side preview, single downloads and a ZIP — nothing uploaded.NEW
Health
34Body Index
7BMI CalculatorEnter height in cm and weight in kg to get your Body Mass Index via the Quetelet formula, with underweight-to-obese categories and your healthy weight range.Body Fat CalculatorPick gender and enter age, height, weight plus waist, neck and hip to estimate body fat with the US Navy method and the Deurenberg formula side by side.Ideal Weight CalculatorEnter gender and height to compare the classic Devine, Robinson and Miller formulas side by side, plus the healthy BMI weight range for your height.Waist-to-Hip & Waist-to-Height Ratio CalculatorEnter waist, hip and height in cm plus gender to get WHR (waist-to-hip ratio) and WHtR (waist-to-height ratio) with apple/pear body-shape classification — WHR ≥ 0.90 for men / 0.85 for women indicates central (apple) fat distribution, WHtR uses 0.5 as a simple health threshold.Body Surface Area (BSA) CalculatorEnter height in cm and weight in kg to compute body surface area with the Mosteller, Du Bois or Haycock formulas — BSA in m² is widely used to dose chemotherapy and to express cardiac index; the calculator can show all three formulas side by side for comparison.Child Growth Percentile Calculator (WHO)Enter age in months, gender, height in cm and weight in kg to see where a 0–5 year-old child falls on WHO weight-for-age, height-for-age and BMI-for-age percentiles — P3/P15/P50/P85/P97 bands are shown with a plain-language note; the tool interpolates between WHO reference points.Skinfold Body Fat Calculator (Jackson-Pollock)Enter gender, age and three skinfold thicknesses in mm (chest/abdomen/thigh for men, triceps/suprailiac/thigh for women) to estimate body density and body-fat percentage with the Jackson-Pollock 3-site formula — reference ranges and measurement tips are included.
Energy & Metabolism
6Calorie CalculatorType in grams of protein, carbs and fat to convert them to kilocalories with the 4-4-9 Atwater rule, plus a quick reference table of food calories per 100 g.BMR CalculatorEnter gender, age, height and weight to compute your basal metabolic rate with the Mifflin-St Jeor formula, then your daily burn at light, moderate and high activity.Exercise Calorie Burn Calculator (MET)Enter your weight, exercise duration and tick any number of activities from a 60+ MET table to estimate calories burned per activity and in total — kcal = MET × 3.5 × weight kg ÷ 200 × minutes, the standard metabolic-equivalent formula.TDEE Daily Total Energy Expenditure CalculatorEnter gender, age, height, weight, activity level and goal to compute BMR (Mifflin-St Jeor), TDEE and your target daily calories with protein/carb/fat grams — sedentary ×1.2 up to very active ×1.9.Food Calorie Counter & Nutrition CalculatorSearch and pick from 200+ common foods with per-100g calories, protein, carbs and fat; enter the portion in grams to get calories and macros — add several foods to accumulate a running total for a whole meal.Daily Reference Intake Checker (Salt, Sugar, Fiber)Pick a food and its intake in grams to see how its sodium, added sugar and dietary fibre contribute toward the adult daily reference intakes — sodium < 2000 mg, added sugar < 50 g (25 g better), fibre 25–30 g per day.
Sleep Health
6Sleep Cycle CalculatorEnter your wake-up time and get bedtimes for 4 to 6 full 90-minute sleep cycles, minus 15 minutes to fall asleep, so you wake at the end of a cycle and avoid sleep inertia.Best Sleep & Wake Time Calculator (90-min Cycles)Enter your target wake time (or planned bedtime) and this tool walks back / forward in 90-minute sleep cycles to give you 3–4 schedules — about 4.5 h, 6 h, 7.5 h or 9 h of sleep — so you wake between cycles feeling less groggy.Caffeine Window Calculator — Latest Intake Time & Bedtime ResidualEnter intake time, dose (50–500 mg), half-life and bedtime; a first-order elimination model solves the latest intake time and the residual left at bedtime in mg and as a share of the dose, with a decay timeline across 0/1/2/3 half-lives, drink caffeine values and population half-life ranges.Nap Guide — Best Nap Duration & TimingPick a nap length (10 / 20 / 30 / 60 / 90 minutes) and optionally your wake time: get a plain-language explanation of what each duration does, the recommended midday window (about 12:30–14:00) and the latest suggested start.Sleep Debt Tracker — Log & AccumulateLog last night’s actual sleep in hours with your recommended target (7 / 8 / 9 h): the tool computes tonight’s difference (debt or surplus), the running accumulated debt since the first record and your average sleep — all kept in your browser.Sleep Self-Assessment Quiz (10 Questions)Answer 10 simple questions about your sleep (each 0–3 points): falling-asleep time, night awakenings, early waking, daytime sleepiness, snoring, satisfaction, daytime energy, pre-sleep state, routine regularity and morning recovery. Total 0–30 gives a reference band.
Daily Health
5Water Intake CalculatorEstimate how many millilitres of water an adult should drink each day from weight, activity level and hot-weather factor, split into morning, noon and evening sips.Quit Smoking Savings & Health Benefits CalculatorEnter cigarettes per day, price per pack (20 cigs) and days since quitting to see money saved and cigarettes not smoked, plus a body-recovery milestone timeline — after 20 minutes blood pressure drops, after 1 year coronary risk is roughly halved.20-20-20 Eye Rest & Sit-Break ReminderA timer that reminds you every 20 minutes (adjustable 10/20/30) to look 6 metres away for 20 seconds, plus an optional hourly sit-break reminder — with a gentle page banner and optional beep. The 20-20-20 rule reduces digital eye strain.Daily Medication Schedule PlannerEnter the medicine name, times per day (1–4), before/after meals and start date to get a suggested daily dosing timetable — 2 times: 08:00/20:00, 3 times: 08:00/14:00/20:00, 4 times: 08:00/12:00/16:00/20:00 — plus a 7-day sample plan.Health Checkup Checklist by Age & GenderPick your age group (20+/30+/40+/50+/60+) and gender to get a suggested checkup item list — blood routine, urine, blood pressure, BMI as base; 40+ adds lipids, glucose, liver/kidney, abdominal ultrasound; 50+ adds tumor markers, bone density, eye fundus; 60+ adds carotid ultrasound and cognitive screening; women add breast ultrasound and cervical screening, men add prostate items.
Health Records
3Blood Pressure Tracker & Trend ChartLog systolic and diastolic blood pressure with date, optional heart rate and note; the record is classified against the reference ranges (<120/80 normal, 120-139/80-89 normal high, 140-159/90-99 grade 1, ≥160/100 grade 2) and plotted on a trend chart. History stays in your browser only.Blood Glucose Log & Trend ChartLog fasting or 2-hour post-meal blood glucose (mmol/L) with date and optional note; readings are classified against the reference ranges (fasting 3.9–6.1, post-meal 2h under 7.8) and plotted on a trend chart. History stays in your browser only.Weight & Body Fat Tracker with Trend ChartLog weight (kg) and optional body fat percentage (%) with date; the change since your last entry, averages and a dual-series trend chart are computed automatically. History stays in your browser only.
Baby & Maternal
7Baby Growth Percentile Calculator (0–24 Months)Enter your baby’s gender, age in months (0–24) and a weight, length or head-circumference reading to check its WHO 0–2 year growth percentile band — e.g. a 6-month-old boy weighing 8.2 kg falls around P50–P85.Child Vaccination Schedule Checker (0–6 Years)Enter your baby’s current age in months (0–84) to list each routine vaccine dose with its due status — e.g. at 6 months the 3rd HepB and 1st MenA doses are due, with overdue-dose reminders.Pregnancy Weight Gain Calculator (Pre-pregnancy BMI & IOM Range)Enter pre-pregnancy height and weight to get your pre-pregnancy BMI and the IOM recommended total weight gain — e.g. a woman with BMI 22 should gain 11.5–16 kg in pregnancy; add current week and weight to see progress.Baby Complementary Food Timeline (Starting at 6 Months)Enter your baby’s current age in months (0–36) to see the matching complementary-feeding stage — e.g. 7–9 months means varied purees and minced foods, 10–12 months means finger foods and self-feeding practice.Period & Ovulation Forecast CalculatorEnter your average cycle length, period length and the first day of your last period; the tool forecasts the next 6 periods, ovulation windows and safe-day hints, and renders a highlighted 3-month calendar. All computing stays in your browser.Menstrual Cycle Log & Trend AnalysisRecord each period start date, its length (days) and symptoms; the tool computes your average cycle, average period length and a forecast of the next period. History stays in your browser only.Baby Age Calculator — Months & Days Since BirthCalculate your baby's exact age: enter the birth date and instantly get years, months and days, total days since birth, month age, and the current developmental stage (newborn, infant, toddler, preschooler).
Daily
79Text Tools
9Character CounterCount characters with or without spaces, words, lines, paragraphs and UTF-8 bytes live as you type, with built-in targets like Weibo 140 or Twitter 280 and a remaining-characters counter.English Case Converter — 12 Naming StylesConvert any English text into 12 naming styles at once: UPPER, lower, Title Case, camelCase, PascalCase, snake_case, kebab-case, CONSTANT_CASE, dot.case, alternating, swap case and text reverse, with live character count and one-click copy.Text SorterSort any text by letters — ascending, descending or shuffled — with optional ignore-case and dedupe, live character counts and one-click copy.Text Find & Replace ToolText Find & Replace is an efficient text-processing tool that finds specific content in any text and replaces it in one batch. Paste your original text, enter the find and replace strings, then press Confirm — everything runs locally and privately. It features live preview: matches are highlighted with the theme color while searching; when replacing, removed text is struck through in red and inserted text is shown in blue, so changes are clear at a glance. Advanced options include ignore case (on by default), match whole words only, and regular expressions (opt-in), covering copy editing, coding, data cleaning and content tidying. The result panel shows the processed text with its character count, ready to copy in one click or download as an image with the brand footer. Every confirm is saved to local history (up to 10 entries) with per-entry copy, per-entry delete and clear-all for easy review. Clean and beautiful UI with light/dark themes and 10 languages — a handy little helper for everyday text work.Text Compare & Diff ToolText Compare & Diff is an intuitive tool that quickly finds the differences between two pieces of text. Paste the original text on the left and the revised text on the right; the tool aligns the lines one by one and computes the longest common subsequence to mark every change precisely: removed content on the left is highlighted in red, added content on the right in blue, and unchanged lines stay as they are. The two panes sit side by side, each taking half the width, with line numbers and character counts always visible, so even long documents are easy to scan for changes. Ideal for code review, copy editing, contract comparison, log analysis and translation checking. Either pane can be copied with one click, and the whole comparison can be downloaded as an image with the site logo for archiving and sharing. Clean and beautiful UI with light/dark themes and 10 languages, fully local and private — a handy little helper for document collaboration and version comparison.Markdown PreviewWrite Markdown on the left and render it live on the right, with GFM tables, fenced code blocks and strikethrough, plus a view and one-click copy of the generated HTML source.Text Repeat ToolText Repeat is a simple and practical text batch generator that helps you output a piece of text repeatedly as many times as you want. Type any content, set the repeat count (5 by default; the tool remembers the count you used last time, so you never need to set it again), then click Confirm to generate the result instantly. The result area shows line numbers and character counts at a glance, making it easy to verify how many copies were generated and the total length. Whether you are creating placeholder text, filling test data, practicing layout, padding copy, or generating repeated paragraphs for website and document testing, one click does it all. The result can be copied with one click, or downloaded as an image together with the site logo for archiving and sharing. Clean and beautiful UI with light/dark themes and 10 languages, fully local and private — an efficient little helper for content creation and batch text processing.Space NormalizerCollapse multiple spaces inside text into exactly N (default 1) and control how many spaces to keep at start and end.Invisible Character Tool — Strip & InjectDetect and strip hidden invisible characters (zero-width space, BOM, soft hyphen, directional marks) from pasted text, or inject them at random positions. One-click copy and PNG download.
Image Tools
17Grid SplitterCut one image into 4, 9, 16 or 25 cells and replace any cell with a different image; lay a heart, star, hexagon, stamp or flower mask over the whole grid with a transparent or custom outside colour, then export a cell, the whole image or a ZIP — all local, nothing uploaded.NEWImage CompressorCompress JPG, PNG, WebP and AVIF images locally in your browser: by quality, by target file size (automatic binary search), by dimensions or a mix of both, with batch processing, format conversion, alpha handling, before/after comparison and ZIP download.Image CropperCrop images online: free crop or lock to 1:1, 4:3, 16:9, 9:16, 21:9 and other common ratios, with rounded-rectangle, circle, hexagon, octagon and heart masks, rotation and straightening, flip, output at selection size or a custom size, split comparison, magnifier and batch ZIP download — all processed locally, nothing uploaded.Image ResizerResize images online: scale by percentage, cap the width or height, limit the long or short edge, or set exact dimensions with stretch, padded fit or centre crop. Built-in presets for avatars, product shots and video covers, plus batch processing, no-upscale protection, DPI tags and before/after comparison.Image PreviewOpen many images at once in your browser: JPG, JPEG, PNG, WebP, GIF, BMP, ICO, SVG, AVIF, HEIC and TIFF. Previous and Next navigation, reset, rotate, zoom in and out, fit to window, flip, full screen and a thumbnail strip, plus page-by-page browsing for multi-page TIFF, keyboard and wheel controls — nothing is uploaded.NEWPNG to WebPBatch-convert PNG to WebP online: keeps the alpha channel, offers adjustable quality and a near-lossless option, with compatibility notes, rotation and a long-edge limit, side-by-side comparison, ZIP download and a CSV report — all local in your browser, nothing uploaded.PNG to JPGBatch-convert PNG to JPG or JPEG online: transparent areas are filled with white or a custom colour, with adjustable quality, rotation and filenames, side-by-side comparison, ZIP download and a CSV report. Phone photos are auto-rotated from EXIF; everything runs locally, nothing is uploaded.Image WatermarkBatch-watermark images with text and a logo online: single, tiled, diagonal, single-row or single-column layouts, adjustable font, rotation, outline, shadow, opacity and blend mode, PNG / JPG / WebP / BMP export, live preview, split comparison, ZIP download and a CSV report — all local, nothing uploaded.Image to PDFMerge photos, screenshots and scans into one PDF locally: drag-sort and rotate images, A4 to B5 or adaptive page sizes, contain / cover / stretch / original-size fit, lossless JPG and PNG embedding, grid layouts, page numbers and headers, tall-image splitting, paginated preview and Blob export — nothing is uploaded.HEIC to JPGBatch-convert iPhone HEIC and HEIF photos to JPG locally in your browser: adjustable quality and transparency fill, orientation correction, a batch list, Previous and Next side-by-side preview, single downloads and a ZIP — nothing uploaded.NEWHEIC to PNGSave HEIC and HEIF photos losslessly as PNG: every decoded pixel and the alpha channel are preserved, making it ideal for further editing, cut-outs and long-term archiving, with batch handling, orientation correction, side-by-side preview and ZIP download — all local, nothing uploaded.HEIC to WebPTurn iPhone HEIC photos into web-friendly WebP: keeps transparency, offers an adjustable quality slider and a live before-and-after size comparison, with batch handling, Previous and Next preview, single downloads and a ZIP — decoded locally, nothing uploaded.WebP to JPGBatch-convert WebP images into widely supported JPG locally in your browser: adjustable quality and transparency fill, orientation correction, a batch list, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; nothing uploaded.NEWWebP to PNGSave WebP images losslessly as PNG: every decoded pixel and the alpha channel are preserved, making the result ideal for further editing, cut-outs and long-term archiving, with a batch list, orientation correction, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; all local, nothing uploaded.NEWAVIF to JPGBatch-convert AVIF images into widely supported JPG locally in your browser: adjustable quality and transparency fill, orientation correction, a batch list, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; nothing uploaded.NEWAVIF to PNGSave AVIF images losslessly as PNG: every decoded pixel and the alpha channel are preserved, making the result ideal for further editing, cut-outs and long-term archiving, with a batch list, orientation correction, Previous and Next side-by-side preview, single downloads and a ZIP. Switch target formats at any time; all local, nothing uploaded.NEWAVIF to WebPTurn AVIF photos into web-friendly WebP: keeps transparency, offers an adjustable quality slider and a live before-and-after size comparison, with batch handling, Previous and Next preview, single downloads and a ZIP — decoded locally, nothing uploaded.NEW
Documents & Office
2DOCX to PDFConvert Word documents to PDF in batches right in your browser: drag in multiple files, set paper size and margins, choose searchable text or image-based output, follow per-file progress, skip failures, preview and compare the result, download a ZIP and export a conversion log, with no upload.Batch RenameRename files locally in bulk: pick a folder (read-only) or a batch of files, preview the result through normalization, find-and-replace, filtering, case, prefix/suffix, numbering and extension, then export a ZIP copy or a rename manifest. Files are not uploaded and not changed — download to take effect.NEW
Time Tools
7Age CalculatorGet your exact age in years, months and days, the countdown to your next birthday, plus your Western zodiac sign and Chinese zodiac animal.Timestamp ConverterLive Unix timestamp in seconds and milliseconds, with bidirectional conversion between timestamp and local date and time, for developers.Date DifferencePick two dates and get the total days, total weeks and a year-month-day combo at once, then add or subtract N days or months from a start date. Leap years handled, great for age and project duration.Time CalculatorPick two date-times and instantly get the gap in days, hours, minutes and seconds plus total seconds; or add or subtract a duration in days-hours-minutes-seconds to a start moment.Countdown TimerCount down to a target date and time or a set duration, live in days, hours, minutes and seconds, with pause, resume and reset, for birthdays, exams and events.Learn to Tell TimeA beautiful teaching clock for kids: explore the dial and hands, set any time with sliders, then practice o’clock, half-past, 5-minute and any-time quizzes.World Clock — Live Time ZonesAn interactive world time map: 24 equal time-zone strips, live clocks for the world's major cities, add any city by IANA timezone, all stored locally.
Convert & Generate
4Unit ConverterConvert length, weight, temperature, area, volume, speed, time and data units instantly as you type, with no lookup tables.Color ConverterConvert between HEX, RGB, HSL and HSV live, pick colors with a color picker and copy each format value in one click, for web design.Color MixerBlend two or more colors into one by averaging their RGB channels, add up to 8 colors, watch the result live, copy or download.Color Overlap & WheelThree-circle color overlap: additive RGB on black and subtractive HSB on white, plus a 360° hue wheel to pick any color.
Number Tools
14Number to Chinese Uppercase ConverterConvert numbers into Chinese financial uppercase (壹贰叁肆伍…) — ideal for invoices, receipts and official documents — and read Chinese uppercase amounts back into numbers, with decimals (角分厘), negatives and up to 15 integer digits, live validation, recent 10 records and PNG download.Number to Chinese Reading ConverterConvert Arabic numerals into Chinese reading (一亿二千三百四十五万六千七百八十九, 一万亿, 零点四五) and read Chinese readings back into numbers, with traditional forms, 两/〇, 点 decimals, 又/分之 fractions, negatives, live validation, recent 10 records and PNG download.Number to Roman Numerals ConverterConvert integers into standard Roman numerals (I, V, X, L, C, D, M) and back — full range 1–3999, strict rule validation with instant hints, recent 10 records, one-click copy and PNG download.Number to English Words ConverterConvert integers into English words and back: one, twenty-three, one hundred, one million — with negatives up to ±999 trillion, live validation, recent 10 records, one-click copy and PNG download.Chinese & English Big Number Unit ConverterConvert between Chinese big-number units (万, 亿, 兆) and English ones (thousand, million, billion, trillion): 1.5亿 ⇄ 150 million, 1万亿 ⇄ 1 trillion, with compound expressions such as 1亿5000万, live validation, recent 10 records and PNG download.Number to English Ordinal ConverterConvert numbers to English ordinal forms and back: 21 → 21st / twenty-first, 101 → one hundred first, with negatives and up to 999 trillion, suffix rules explained, live validation, recent 10 records and PNG download.Amount to English Money Words ConverterConvert amounts into English money words and back: 123.45 → One Hundred Twenty-Three Dollars and Forty-Five Cents, supporting USD, EUR, GBP, CNY, JPY and INR with correct plurals and minor units, live validation, recent 10 records and PNG download.Number to Thousand-Separated FormatFormat numbers with thousands separators and parse them back: 1234567.89 → 1,234,567.89 (international) or 1 234 567,89 (European), both styles supported, negatives and up to 15 digits, live validation, recent 10 records and PNG download.Number to Pinyin Converter — Chinese Reading & TonesConvert Arabic numerals into Mandarin pinyin reading (yī bǎi èr shí sān) with the Chinese reading form (一百二十三), and parse pinyin back into numbers — supports integers, decimals, negative numbers, 两/liǎng, decimals with 点, mixed fractions with 又/分之, live validation, recent 10 records, one-click copy and PNG download.Number Abbreviation Converter — K / M / B / TConvert numbers into compact abbreviations (12345 → 12.35K, 1500 → 1.5K, 1234567 → 1.23M) and parse abbreviations back into full numbers — supports K, M, B, T levels, decimals, negative numbers, case-insensitive suffixes, live validation, recent 10 records, one-click copy and PNG download.Scientific Notation Converter — Number ↔ e / ×10ⁿConvert numbers into scientific notation (12345 → 1.2345e+4, 0.000123 → 1.23e-4) in both e-notation and ×10ⁿ styles, and parse scientific notation back into plain numbers — accepts 1.2345E3, 3.14×10², *10, ·10^ forms, superscript digits, live validation, recent 10 records, one-click copy and PNG download.Number Rounding Calculator — Decimal Places & Significant FiguresRound numbers to a chosen number of decimal places (3.14159 → 3.14) or significant figures (0.00012345 → 0.0001235) with half-up, half-even (banker), ceiling and floor rules — handles carry overflow like 9.999 → 10.00 and 9999 → 10000, live validation, recent 10 records, one-click copy and PNG download.Greek Numerals Converter — Number ↔ Greek numerals (1-9999)Convert numbers 1–9999 into Greek numerals (1234 → ͵ασλδʹ) and parse Greek numerals back into numbers — supports lowercase and uppercase symbols, thousands marker ͵ and unit marker ʹ, descending order validation, live validation, recent 10 records, one-click copy and PNG download.Unicode Character Code Converter — Character ↔ Code PointGet the Unicode table for any character (A → U+0041, 65, A, A) and turn code points back into characters — accepts decimal, U+0041, 0x41, \u{1F600}, \u0041, 😀 and 😀 forms, supports emoji surrogate pairs, multiple tokens, live validation, recent 10 records, one-click copy and PNG download.
Random Tools
5Dice RollerRoll 1 to 9 3D dice at once, 3 by default; cryptographic randomness picks the faces before the tumble, with clacks, per-die values, sum stats and the last ten rolls.NEWRandom Password GeneratorBuild strong random passwords with your chosen length and character sets, filter out ambiguous characters and read the live strength meter, then copy in one click.Random Number GeneratorDraw true random numbers in a min to max range, with count, allow duplicates or not, auto-sort and a history list, great for draws and lotteries.Random Name PickerPaste a list and start drawing: weighted entries, prize tiers, single or batch draws, repeat or no-repeat, countdown reveal and a fullscreen stage, with names and records stored in local IndexedDB.Spin Wheel PickerPaste a list into the wheel, let the weights size the sectors and the pointer decide: the winner is drawn with cryptographic randomness first and the angle is solved backwards, then verified against the pointer once the wheel stops. Sector images and colors, multiple pools, no-replacement draws, win history and stats, sound, confetti and a fullscreen stage, all stored locally.
Loans & Mortgages
5Early Repayment CalculatorCompare interest savings for partial or full early repayment of a mortgage: keep the payment and shorten the term, or keep the term and reduce the monthly payment. See remaining balance, new payment, new term and total interest saved.Loan CalculatorEnter the principal, annual rate and term in months to compare equal installment annuity against equal principal side by side: monthly payment, total interest, total repayment, plus an amortization schedule.Provident Fund Loan CalculatorCombined provident fund plus commercial loan calculator: estimate the provident fund loan quota from account balance, monthly contribution and house price, then see the combined monthly payment and total interest for both parts.Car Loan CalculatorCar purchase cost in one view: down payment, monthly payment, purchase tax, first-year insurance and registration fee estimates, plus total loan interest and the final out-of-pocket total.Consumer Loan ComparatorConvert the nominal rate of a credit or consumer loan into the real annualized IRR, compare two plans side by side: monthly payment, total cost and true annual rate, so you can spot expensive installment traps.
Savings & Deposits
5Compound Interest CalculatorSee the power of compounding: principal, rate and years with daily, monthly, quarterly, semi-annual or annual compounding, plus final value, total interest and doubling time.Savings Interest CalculatorEnter the principal, the annual rate and the term to compare simple interest against compound interest side by side: total interest, final amount, plus a year-by-year table.Periodic Deposit CalculatorPlan a periodic deposit plan: monthly deposit, annual rate and term - instantly see total deposits, interest and final balance with a month-by-month table using the standard bank formula.Inflation & Purchasing Power CalculatorFind out how inflation eats your money: amount, annual inflation rate and years - get the future amount needed and the real purchasing power lost, shown side by side.Certificate of Deposit CalculatorLarge certificate of deposit calculator: amount, rate and term with interest paid at maturity or monthly, total interest, final amount and a period-by-period table.
Investment & Returns
6Stock P&L CalculatorCalculate stock buy and sell fees, stamp duty, transfer fee, profit or loss and return rate with a full cost breakdown.Fund DCA CalculatorSimulate monthly fund investments with compound returns: multiple rate scenarios, trend curves, total invested, final value and gains.Annualized Return CalculatorTurn a period return into annualized return, convert 7-day annualized yield and per-10k earnings, compare products of different terms.Take Profit & Stop Loss CalculatorCompute risk-reward ratio, profit and loss at target prices, and the new average cost after adding positions.Averaging Cost CalculatorCompute the average cost of batched purchases: enter price and quantity per batch, get averaged cost and floating P&L.Treasury Bond Yield CalculatorEstimate savings treasury and book-entry treasury bond returns: principal, coupon, term and approximate yield to maturity, with policy update date noted.
FX & Currency
4Currency ConverterMulti-currency conversion between USD, EUR, GBP, JPY, HKD and more, with built-in sample rates — not real-time, for reference only.Gold & Metals ConverterConvert grams, ounces and kilograms, compute prices from USD/oz to CNY/g, precious metals weight and price in one tool.Remittance Fee EstimatorEstimate cross-border remittance fees, intermediary charges and FX spread loss, get the actual amount received and total cost rate.Precise FX ConverterPrecise conversion for JPY, KRW and other large-denomination currencies with four-decimal precision and bidirectional exchange.
Lifestyle Tools
17Dates & Anniversaries
4Anniversary Countdown & Memorial LedgerKeep an anniversary and memorial ledger — add any name plus a date (optionally repeating every year) and instantly see the next occurrence and how many days remain. Records are stored locally in your browser with individual copy / delete and clear-all.Life Calendar — Days Lived CalculatorEnter your birth date and an expected lifespan to see exactly how many days, weeks, months and years you have lived, plus your overall life progress bar. Key milestones — 10,000 days, 20,000 days, 50th birthday and more — are listed with their dates so you can plan ahead.Lunar Calendar & Solar Terms ConverterConvert between the Gregorian (solar) calendar and the Chinese lunar calendar for any date from 1900 to 2100, and see the year ganzhi (stem-branch), Chinese zodiac and whether the day is a solar term. The full 24 solar terms table of the selected year is shown for reference.Love Anniversary & Relationship Days CounterEnter the day you got together to see exactly how many years, months and days you have been together, and get the dates of upcoming relationship milestones — 100 days, 1 year, 500 days, 1000 days, 1314 days, 5200 days. The annual sweet-hearts calendar (13 romantic days from Jan 14 to Dec 14) is included for planning surprises.
Money & Splitting
4Expense Ledger — Simple Money TrackerA lightweight local expense and income ledger: enter amount, type (income/expense), category and a note, then watch the running total of income, spending and balance update instantly. Records stay in your browser — nothing is uploaded. Categories cover food, transport, housing, shopping, entertainment and more.AA Bill Splitter — Split & SettleSplit a bill evenly among any number of people, or enter how much each person already paid to see exactly who owes whom and who gets money back. Per-person share, needs-to-pay and refund amounts are calculated instantly — great for dinners, trips and shared rent.Promotion Mix Calculator — Discounts & CouponsStack full-reduction (spend X save Y), discount percentage and coupon amount in one calculation: enter the original price, threshold, cut and coupon to get the final payable, or use the discount tab for percentage-off and multi-item orders. Shows exactly how each promo applied.Utility Bill Splitter — Even or By UsageSplit water, electricity or gas bills evenly among roommates, or by actual usage: enter the total fee and the number of people for an equal share, or enter each person's usage to split proportionally. Shows each person's share rounded to cents.
Habits & Focus
4Focus Timer — Deep Work CountdownA clean focus timer for deep work: pick a 25 / 45 / 90 minute session (or set your own), press start and work without distractions. The ring shows progress, sessions that finish are recorded in your local history, and a gentle tone lets you know the session is over.Habit Tracker — Daily Check-inTrack habits with one tap a day: add habits like exercise, reading or early rising, tap today's check-in to build your streak. Your habit list stays in the browser, streaks are counted automatically, and every check-in is saved to recent records.21-Day Plan — Three Weeks to a New HabitPlan a 21-day challenge: set a goal and a start date, check in once a day, and watch the progress bar fill. The plan is stored in your browser; every daily check-in is also saved to recent records.Priority Matrix — Eisenhower QuadrantsSort tasks into the four Eisenhower quadrants — important & urgent, important not urgent, urgent not important, neither. Paste one task per line, save, and follow the suggested order: do, schedule, delegate, delete.
Home & Household
2Electricity Cost Calculator — Appliance Power UsageEstimate your monthly electricity bill: add appliances with their wattage, quantity and daily running hours, set your local electricity price, and see total kWh and cost instantly, with a per-appliance breakdown.Renovation Budget Calculator — Cost Per Square MeterEstimate your home renovation budget: enter the floor area and pick a standard (simple, mid-range or premium), and get a total estimate plus a typical split between hard decoration, soft furnishing and appliances.
Family & Pets
2Pet Age Calculator — Cat & Dog Years to Human YearsConvert your pet's age into human years: pick cat or dog (small, medium, large breed) and enter the age — get the equivalent human age using the standard first-two-years + per-year rule.Pet Food Amount Calculator — Daily Feeding GuideEstimate how much to feed your cat or dog per day: choose cat or dog, enter the weight, and get a daily dry-food range in grams, plus feeding frequency guidance.
Computer
24Data Conversion
12JSON to XML ConverterPaste any JSON and get well-formatted, pretty-printed XML in seconds. Runs 100% in the browser with the open-source fast-xml-parser library — no upload, no sign-up.JSON to CSV ConverterPaste any JSON and get a clean, spreadsheet-ready CSV in seconds. Runs 100% in the browser with the open-source papaparse library — no upload, no sign-up.XML to JSON ConverterPaste any XML and get a clean, ready-to-use JSON object in seconds. Runs 100% in the browser with the open-source fast-xml-parser library — no upload, no sign-up.JSON to TSV ConverterPaste any JSON and get a clean, tab-separated TSV in seconds, where commas inside fields need no escaping. Runs 100% in the browser with the open-source papaparse library — no upload, no sign-up.CSV to JSON ConverterPaste any CSV and get a structured JSON array in seconds. Runs 100% in the browser with the open-source PapaParse library — no upload, no sign-up.CSV to XML ConverterPaste any CSV and get a structured XML document in seconds. Runs 100% in the browser with the open-source PapaParse and fast-xml-parser libraries — no upload, no sign-up.JSON to YAML ConverterPaste any JSON and get clean, readable YAML in seconds. Runs 100% in the browser with the open-source js-yaml library — no upload, no sign-up.TSV to JSON ConverterPaste any TSV (tab-separated values) and get a structured JSON array in seconds. Runs 100% in the browser with the open-source PapaParse library — no upload, no sign-up.TSV to XML ConverterPaste any TSV (tab-separated values) and get a structured XML document in seconds. Runs 100% in the browser with open-source PapaParse and fast-xml-parser libraries — no upload, no sign-up.XML to YAML ConverterPaste any XML and get clean, readable YAML in seconds. Runs 100% in the browser with open-source fast-xml-parser and js-yaml libraries — no upload, no sign-up.YAML to JSON ConverterPaste any YAML and get standard JSON in seconds. Runs 100% in the browser with the open-source js-yaml library — no upload, no sign-up.YAML to XML ConverterPaste any YAML and get a structured XML document in seconds. Runs 100% in the browser with open-source js-yaml and fast-xml-parser libraries — no upload, no sign-up.
Encoding & Conversion
5Base64 Encoder / DecoderEncode text to Base64 and decode it back through UTF-8 bytes so Chinese, emoji and other Unicode characters survive the round trip, with copy and result feedback.URL Encoder / DecoderPercent-encode and decode URLs and query parameters in both encodeURIComponent and encodeURI modes, correctly escaping Chinese and spaces, with friendly errors on malformed sequences.Base ConverterConvert integers between binary, octal, decimal, hexadecimal and any base from 2 to 36, using digits 0-9 then letters a-z, with a live common-base reference table.HTML Entity Encoder / DecoderConvert characters to and from HTML entities: named ones (amp, lt, gt, quot) and numeric hex entities, with non-ASCII auto-escaped and a per-character mapping table.Unicode Escape Encoder / DecoderConvert characters to and from uxxxx escapes, splitting emoji and other supplementary-plane characters into correct surrogate pairs, with per-character code point, UTF-8 bytes and UTF-16 units.
Developer Tools
4JSON FormatterFormat, minify and validate JSON in the browser, pretty-printing with two-space indentation, pointing at the exact line, column and snippet on error, with object and array structure stats.Regex TesterTest regular expressions live with match highlighting and hit count, capture groups shown per match, flags global, case-insensitive, multiline and more, plus built-in email and phone examples.UUID GeneratorGenerate RFC 4122 version-4 UUIDs locally in the browser with crypto.randomUUID, from 1 to 20 at a time, uppercase or lowercase, hyphens optional, copy one or all.Hash GeneratorCompute MD5, SHA-1, SHA-256, SHA-384 and SHA-512 digests of text or a local file live, with one-click copy and uppercase toggle, for file checksums and integrity verification.
Generators
3Password GeneratorGenerate strong random passwords locally in the browser, length 4 to 128, with selectable upper or lower letters, digits and symbols, live entropy and strength rating, up to 10 at once.QR Code GeneratorGenerate a QR code from any text, link or phone number, with adjustable size, margin, error-correction level and foreground or background colors, live preview and one-click HD PNG download.Barcode GeneratorTurn digits or characters into a scannable one-dimensional barcode in CODE128, EAN-13, EAN-8, UPC-A, CODE39 or ITF-14, with separate controls for bar width, height, scale, bar and background colours, readable-text font, position and quiet-zone margin, plus a live preview of the real pixel size and PNG or SVG export.
Learning Tools
12Math
6CalculatorA pocket-style immediate-execution calculator on screen: type on your keyboard or tap the keys, chain add-subtract-multiply-divide, use percent and sign toggle, with a friendly divide-by-zero message.Formula SheetQuick-reference math formula sheet: algebra, geometry, trigonometry and physics formulas at a glance, with fast lookup for revision and homework.Statistics CalculatorOnline statistics calculator: mean, median, mode, variance and standard deviation in one click — enter data and get instant results for homework and analysis.Triangle CalculatorOnline triangle calculator: given two sides and an angle or three sides, auto-solve remaining sides, angles, area and perimeter, with degree/radian modes.Coordinate SystemCoordinate plane learning tool: plot points, draw shapes and read coordinates to intuitively understand quadrants and point positions, with transformation drills.Number Line and Number ClassificationInteractive number line learning tool: mark integers, fractions and decimals on a line to understand rational number classification and comparison, with classification drills.
Physics
3Velocity & Acceleration CalculatorKinematics calculator for uniformly accelerated motion: swap velocity, acceleration, displacement and time, with clear formulas for physics homework.Newton's Second Law CalculatorNewton's second law calculator: given any two of force, mass and acceleration, the third is computed instantly, with unit conversion for mechanics problems.Simple Harmonic Motion Period CalculatorSimple harmonic motion period calculator: derive period and frequency from mass & spring constant or pendulum length instantly, with formula notes.
Chemistry
3Periodic TableOnline periodic table: 118 elements arranged by groups — click to view atomic mass, electron configuration and common properties for chemistry study.Molecule Structure ViewerMolecular structure viewer: 3D visualisation of common molecules with clear atoms and bonds to understand spatial configuration and chemical bonding.Chemical Equation BalancerChemical equation balancer: enter reactants and products, get balanced coefficients with step-by-step process, covering common reaction types.
About This Site
I built AI DO TOOL to turn the small everyday needs we all run into into tools you can open and use right away.
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