AVIF to WebP — Turn AVIF into Web-Friendly WebP Online, Keep Transparency and Adjust Quality, Compare Size Live, Processed Locally
AVIF compresses well, but its browser support arrived years after WebP, and older Safari builds, some content management systems and upload endpoints still cannot read it — dropping it into a page forces a picture-element fallback and raises maintenance cost. WebP, by contrast, is natively supported by almost every modern browser and site builder, stays far smaller than JPG, and keeps an alpha channel, making it the most worry-free web image format for now. This page decodes the AVIF fully in your browser and re-encodes it as WebP, with an adjustable quality slider and a live before-and-after size comparison, and transparency is preserved too. Drag in several files at once, watch each one’s status and size in the batch list, step through the preview with Previous and Next to compare side by side, then download one image or pack the whole batch into a ZIP. The target-format dropdown switches to JPG or PNG at any time, and already-decoded images re-export automatically without being imported again. Decoding uses the browser’s own capability, nothing is uploaded and the page still works offline; the result is a clean new file that does not automatically carry over EXIF shooting time, camera model or location. An animated AVIF contributes only its first frame, and the batch list also lets you retry a failed file on its own or download just a few images.
Import images
Target format
All three formats reuse the same decoded pixels, so switching re-exports automatically — no need to import again.
WebP balances size and an alpha channel and fits web pages well; very old Safari and legacy viewers may not open it.
Higher values keep more detail and produce larger files. Around 0.85 suits photos; push it higher for screenshots.
A few AVIF files carry an orientation flag and decode sideways. Correct them here.
Leave it empty to keep the original name; the extension is replaced with the output format.
Preview and export
Batch list
0 / 0 DoneNo images imported yet.
How to use
- Drag .avif images into the import area, or click Choose images to select several at once; Ctrl+V pastes a screenshot too. The tool identifies the real format from the file header, so a wrong extension does not matter.
- Keep the target format on WebP and start with quality around zero point eight five to see the output size, then nudge it either way: push a photo too hard and the sky bands; for text screenshots, watch whether strokes go soft.
- Transparent areas are preserved fully by WebP, with no fill colour needed; a few AVIF files carry an orientation flag and decode sideways, so correct those with Extra rotation.
- Use Previous and Next in the preview to check both panes image by image, then download the current one, download individual rows from the batch list, or pack everything into a ZIP. Changing the dropdown re-exports the already-decoded images automatically.
Frequently asked questions
Why convert AVIF to WebP at all?
Because WebP’s browser and site-builder support predates AVIF by nearly a decade; older Safari, many content management systems and upload forms still cannot read AVIF, and dropping it into a page often means a picture-element fallback and maintaining several asset variants. WebP stays far smaller than JPG, keeps an alpha channel, and works almost everywhere, making it the most worry-free format to ship today. If your audience is all on the newest browsers, staying with AVIF is also fine.
Does converting to WebP lose quality again?
A little, usually imperceptibly. A lossy AVIF is already compressed once, and decoding to pixels before re-encoding with WebP’s quantisation table is a second lossy pass; sky gradients and high-contrast edges are the likeliest places to show faint banding or ringing. Above quality zero point eight five it is essentially invisible at normal sizes, and if the source was a lossless AVIF the loss is lower still. To avoid a second loss entirely, use the PNG page.
Will the transparent background be kept?
Yes. WebP supports a full alpha channel, so transparent areas from the AVIF come across intact; cut-out product shots and logos with rounded or feathered edges stay transparent and can be dropped onto any background. This differs from JPG, which has no transparency dimension and can only fill transparent areas with a solid colour.
What if an old browser cannot open WebP?
A very few ancient browsers genuinely lack WebP support. On the web the safest pattern is a picture element: put WebP in the source and add a JPG as the default fallback, so unsupported browsers automatically drop back to JPG. This page only turns the image into WebP; whether to add that fallback is up to your front-end code. If you want maximum compatibility in one file, simply choose the JPG page instead.
Are my images uploaded to a server?
No. Decoding, orientation correction, quality adjustment and encoding all happen in the browser, AVIF pixels are unpacked by the browser itself, image data never leaves your device and the page has no upload endpoint. Once it has loaded you can even keep converting offline. The flip side is that the list is gone when you close the tab, so keep your own backup of important originals; the output is a brand-new file and no EXIF shooting data is carried over.
What is it
AVIF and WebP were both built to be smaller, and the trade-off is between compatibility and compression. AVIF, launched in 2019 with AV1 video coding, packs data into a HEIF container; its lossy mode uses intra-frame prediction and adaptive quantisation to push size extremely low — often a notch smaller than WebP at the same perceived quality — but it was finalised later and browsers adopted it slowly, so older Safari, some content management systems and upload forms still cannot read it. WebP, released by Google in 2010 on VP8 intra coding, offers lossy, lossless, alpha and animation in one specification, and is natively supported by mainstream browsers and site builders, staying far smaller than JPG while keeping an alpha channel — the most worry-free web format to ship today. Turning AVIF into WebP means the browser first unpacks the AVIF into full pixels and then re-packages them with WebP’s codec, where the quality slider controls quantisation strength: higher values keep more detail and produce larger files. Both support alpha, so transparent areas are preserved as-is rather than forced onto a fill colour as JPG would. EXIF, ICC and animation frames in the container do not come along, and a multi-frame AVIF contributes only its first frame. The tool identifies the real format from the file header, so a wrong extension does not matter.
Origin & history
Lay the timeline out and two modern formats a decade apart meet on the same machine. WebP comes first: in September 2010 Google released it on the acquired VP8 video codec, using a RIFF container for image data. The first version was lossy only; 2011 added an alpha extension, and around 2012 came separate lossless coding, metadata and animation, while libwebp was adopted by Chromium, Android and a great many server-side toolchains. Chrome supported it early and Safari only caught up in 2020, so picture elements and server-side content negotiation by request header were effectively mandatory for years. The other strand begins in February 2019: Netflix, with several partners, released AVIF, built on the open AV1 video codec and packed into a HEIF container, borrowing video intra-coding’s high compression for still images; the first version already offered lossy, lossless, alpha and animation, and libavif was adopted by mainstream browsers in turn. Then came the long rollout: Chrome supported it by the end of that year, Firefox only in 2021, and Safari not until 2024 — a full decade behind WebP. It is precisely that decade of lag that let WebP become the default readable format for site builders, content management and upload endpoints first, while AVIF still shows a blank box in many older environments. The real solution needed no new algorithm: canvas toBlob had long accepted image/webp with a quality argument, so the encoding side was never the obstacle, and once browsers could unpack AVIF pixels natively, local decoding plus local re-encoding became the most dependable combination — one that does not even need an upload endpoint. Today a single click turns the new format back into the most universal web format of the moment; what looks like merely skipping one upload is in fact handing a piece of computation that should have stayed local back to the local device.For sites and teams that process large volumes of images every day, this local relay pushes the compatibility problem onto the user’s own device and quietly keeps the assets private.
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