JSON Formatter
Format, beautify and validate JSON instantly in your browser. Pinpoints syntax errors by line, handles large files, and never uploads your data.
Related tools
All Developer tools →This tool runs entirely in your browser. Nothing you enter is sent to our servers, so there is nothing for us to store or see.
About the JSON Formatter
Paste JSON and get it back properly indented and readable. If the JSON is invalid, you get the exact line and column of the problem along with what the parser expected — which is usually faster than reading a minified API response by eye.
The formatter runs entirely inside your browser using the same JSON parser your browser already uses for every website it loads. Nothing is uploaded, which matters more than it sounds: API responses routinely carry access tokens, customer records and internal endpoints, and pasting them into a server-side formatter means handing all of that to someone else. Here there is nothing to hand over — you can disconnect from the internet after this page loads and it will still work.
Choose 2-space, 4-space or tab indentation, or minify to strip every unnecessary byte before shipping to production. Key sorting is available when you need to diff two responses that return the same data in a different order.
How to use the JSON Formatter
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Paste your JSON
Paste into the input box on the left, or drop a .json file onto it. Formatting starts as soon as you stop typing — there is no button to press.
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Choose how it should look
Pick 2 spaces, 4 spaces or tabs. Choose Minify instead to strip all whitespace, or turn on Sort keys to put object keys in alphabetical order.
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Fix anything invalid
If the JSON will not parse, the message below the boxes gives the line and column where the parser gave up and what it expected to find there.
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Copy or download the result
Use Copy to put the formatted JSON on your clipboard, or Download to save it as a .json file.
Frequently asked questions
Is my JSON uploaded to your server?
No. This tool runs entirely in your browser using its built-in JSON parser. Your data never leaves your device, so there is nothing for us to store, log or see. You can confirm this by opening your browser's network tab while you use it, or by disconnecting from the internet after the page loads — the tool keeps working.
What size of JSON file can it handle?
Files up to roughly 10 MB format comfortably on a typical laptop or phone. Beyond that your browser may pause for a second or two while it parses, because the work happens on your own device rather than on a server. Very large files are better handled with a command-line tool such as jq.
Why does my JSON say it is invalid when it looks fine?
The most common causes are a trailing comma after the last item in an object or array, single quotes instead of double quotes around keys and strings, unquoted keys, or a stray comment. All four are valid JavaScript but none of them are valid JSON. The error message gives you the line and column so you can go straight to it.
What is the difference between formatting and minifying?
Formatting adds line breaks and indentation so a human can read the structure. Minifying removes every optional space and newline to make the file as small as possible for transmission. The data is identical either way — only the whitespace differs, and JSON parsers ignore whitespace entirely.
Does sorting keys change my data?
No. Key order carries no meaning in a JSON object, so sorting is purely presentational and every parser will read the result identically. It is useful when you want to diff two API responses that return the same fields in a different order. Array order is never touched, because in an array the order genuinely is the data.