Developer ToolsNewRuns in your browser
JSON Formatter
Beautify, minify and validate JSON with precise error messages.
About JSON Formatter
Paste a wall of minified JSON and get readable, indented output with syntax highlighting. When the JSON is invalid you get the line and column of the problem rather than a vague "unexpected token", which is usually the difference between a five-second fix and ten minutes of squinting. Everything runs in your browser, so you can safely paste an API response containing real data.
How to use JSON Formatter
- 01
Paste your JSON
Paste into the input box, or upload a .json file from your device.
- 02
Beautify or minify
Press Beautify for readable indented output, or Minify to strip every unnecessary byte.
- 03
Fix any errors
If the JSON is invalid, the message points at the line and column so you can go straight to it.
- 04
Copy or download
Copy the formatted result to the clipboard, or save it as a .json file.
Features
- Beautify with 2-space, 4-space or tab indentation
- Minify to the smallest valid output
- Validation with the exact line and column of any error
- Syntax highlighting for keys, strings, numbers and literals
- Upload a .json file or paste directly
- Key and depth statistics for the parsed document
- Copy or download the result
Frequently asked questions
Everything people ask about the JSON Formatter.
Parsing and formatting happen entirely in your browser — no network request is made with your input. The usual caution about shared or monitored machines still applies.
The three usual culprits are a trailing comma after the last item, single quotes instead of double quotes, and unquoted keys. All three are legal in JavaScript but not in JSON.
Beautify adds indentation and line breaks so a human can read it. Minify removes all optional whitespace so the payload is as small as possible for transmission. The data is identical either way.
Files up to a few megabytes format quickly. Beyond roughly 10 MB the browser may become sluggish, since the whole document has to be parsed and re-rendered at once.
No. Key order is preserved exactly as it appears in the input — only whitespace changes.
Yes, completely. There is no account to create, no trial that expires, no watermark on the output and no feature held back behind a paywall. The site is supported by unobtrusive advertising, not by charging you.
No. JSON Formatter runs entirely inside your browser, so your files never leaves your device. You can confirm this by opening your browser's network tab — there is no upload request.
Yes. Because processing happens locally, there is no copy of your data on any server to leak, subpoena or lose. Nothing is logged and nothing is stored.
Yes. The interface is built mobile-first, with touch-friendly controls and layouts that adapt to small screens. Everything that works on a desktop works on a phone.
Once the page has loaded, yes. All processing is local, so you can carry on working if your connection drops.
Any current version of Chrome, Edge, Firefox, Safari or Opera, on desktop and mobile. If something behaves oddly, updating your browser resolves it in almost every case.
There is no server-side limit because nothing is uploaded. Files up to about 10 MB are comfortable on a typical device; beyond that, processing speed depends on your machine's memory.
Yes. Whatever you produce here is yours — use it in client work, products, packaging or publications. There is no watermark, no licence to accept and no attribution required.
No. There is nothing to keep: your data is never transmitted, and it is cleared from memory as soon as you close or reload the page.
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