A free JSON formatter that never sees your data
Paste JSON. Format, validate, minify, or explore in a tree. Everything runs in your browser — never sent anywhere.
Most online JSON tools use a server-side parser, which means your JSON gets shipped off to their backend to be prettified. That is fine for demo payloads, terrible for API responses that contain tokens, PII, or business logic. This tool uses the browser's native JSON.parse. Nothing leaves your device.
What you can do here
- Format — pretty-print with 2/4-space or tab indent. Handles multi-megabyte payloads.
- Minify — strip all whitespace for the smallest possible transport size.
- Validate — see the exact line and column of any syntax error.
- Sort keys — reorder every object's keys alphabetically, recursively. Arrays keep their order.
- Tree view — click through nested objects and arrays. Click a key to copy its dot-path.
- Escape / Unescape — convert JSON to a string-safe literal and back.
- URL-decode — clean up JSON pulled from URL query params.
Frequently asked
Is my JSON uploaded anywhere?
No. Native JSON.parse runs in your browser. Zero network requests during parsing or formatting.
How is this different from JSONLint or JSON Formatter?
Most alternatives are server-side. This is fully client-side, so sensitive JSON (API keys, PII, tokens) never leaves your device.
Does it support JSON5, comments, or trailing commas?
Strict JSON only for now. If your source has JS-style comments or trailing commas, remove them first — the error message shows the location.
Is there a size limit?
Your browser's memory is the ceiling. Multi-megabyte payloads parse fine on desktop.
Can I click into the tree to copy a path?
Yes — click any key in Tree view to copy its dot-path (e.g. data.users[0].email) to your clipboard.
Can I use it commercially?
Yes, free for any use, no attribution required.