About this JSON formatter
JSON is how APIs, config files and modern apps store structured data — and how developers spend half their debugging lives. A single missing comma breaks the whole file, minified responses arrive as an unreadable wall of text, and comparing two objects is hopeless without consistent formatting. This tool formats, minifies and validates JSON instantly, and when something's wrong it tells you the exact line and column with a snippet of the offending spot.
How to use it
- Paste any JSON — an API response, a config file, a log entry.
- Format pretty-prints it with your chosen indentation; Minify strips every unnecessary character for production; Validate just checks it and describes the top-level structure.
- Tick Sort keys A–Z to normalize key order — the trick that makes two JSON objects diffable in the Text Compare tool.
Why local processing matters here especially
JSON you're debugging is often real data — API keys in headers, customer records, tokens. Pasting that into a random website that processes it server-side is how secrets leak. This formatter runs entirely in your browser: the data never leaves the page, which makes it safe for the exact situations where you need it most.
- Handles large files — hundreds of thousands of lines format in moments.
- Error messages include line, column and a context snippet, so you can fix the file instead of hunting.
- Download the result as a .json file or bounce it back to the input for another pass.
Frequently asked questions
Is it safe to paste API responses with real data?
Yes — formatting and validation run entirely in your browser. Nothing is sent to any server, which is exactly what you want when the JSON contains keys, tokens or customer data.
How do I find the error in invalid JSON?
Press any button and the tool reports the exact line and column of the first problem, with a snippet of the surrounding text. The usual suspects: a trailing comma, a missing quote, or single quotes instead of double.
What does 'Sort keys A–Z' do?
It rewrites every object with its keys in alphabetical order. Two JSON files sorted this way become directly comparable — paste them into the Text Compare tool to see real differences instead of ordering noise.