YAML to JSON Converter — Free Online YAML→JSON Tool

Paste any YAML and get standard JSON in seconds. Runs 100% in your browser with the open-source js-yaml library (MIT) — no upload, no sign-up. Supports nested objects, arrays, strings, numbers, booleans, null, multi-line strings and comments. Perfect for converting Kubernetes YAML, Docker Compose, GitHub Actions and Ansible configs into JSON for API calls, data processing or frontend rendering — private, free, instant.

YAML input Anchor

JSON output

Converted JSON will appear here…

How to use

Paste or type your YAML into the left box — a sample is already loaded on first visit.
The right side updates live as you type (debounced ~250 ms).
Use Copy JSON to copy the result to your clipboard, or Download .json to save it locally.
The left input is remembered in your browser, so you can come back and keep editing.

What is it

YAML describes data with indentation and colons; JSON describes it with curly braces and quotes. YAML is more concise and human-friendly, but many APIs and frontend components only accept JSON. This tool parses your YAML into a JavaScript object with js-yaml, then serializes it to standard JSON with the built-in JSON.stringify, so you can feed YAML configs straight to an API or frontend component.

Notes & fun facts

YAML is a human-friendly data serialization format proposed in 2001. It uses indentation instead of curly braces, colons instead of key-value separators, and dashes instead of array symbols, removing all the repetitive punctuation of JSON. Today YAML is practically the de facto standard for cloud-native configuration: Docker Compose files are YAML, Kubernetes Deployments and Services are YAML, GitHub Actions pipelines are YAML, and Ansible playbooks are YAML. But often you need to convert these YAML configs into JSON — for example, calling an API that only accepts JSON, rendering config data with a frontend component, or importing config into a tool that only supports JSON. When you need to quickly turn a YAML config into JSON, you need a fast, local, server-free tool. This tool does it locally in your browser with js-yaml, supporting nested objects, arrays and multi-line strings, ready to copy and use.

Origin & history

YAML 1.0 was proposed by Clark Evans in 2001, YAML 1.1 was released in 2005, and YAML 1.2 in 2009 aligned with JSON syntax. js-yaml is an MIT-licensed YAML parser/serializer open-sourced in 2011, zero-dependency and browser-friendly, and one of the most popular YAML libraries in the Node.js ecosystem.