JSON Formatter & Validator
Paste ugly JSON, get pretty JSON. The classics never die.
What this does
Paste messy JSON, get clean JSON. The tool checks your input and re-indents it with 2 spaces. Only the whitespace changes: big numbers, 1.0, and escapes come out exactly as they went in. Minify does the opposite: strips every space, newline, and indent for the smallest possible payload. Validate catches the stuff that makes parsers throw.
Common use cases
Debugging API responses. You're staring at a single-line response body trying to find one nested field three levels deep. Formatted JSON with indentation makes that a visual scan instead of a character-counting exercise.
Cleaning up configs. Kubernetes manifests, package.json, Terraform state files. Consistent formatting means diffs show actual changes, not whitespace noise.
Minifying for transport. Stuffing JSON into a query parameter, a cURL command, or anywhere that extra bytes cost you. Format for reading, minify for shipping.
Things to know
JSON is pickier than people remember. Trailing commas, unquoted keys, single quotes instead of double quotes: all illegal. JavaScript allows trailing commas. JSON doesn't. The error message comes straight from your browser's JSON parser. Chrome and Firefox usually include the line and column, though not for every mistake.
Nothing runs until you click a button, so a big paste won't freeze the tab. Input over 500,000 characters gets refused instead of locking up your browser. For anything near that size, the Download button is your friend. Faster to format and save than to scroll through 50,000 lines in a textarea.
Privacy
Everything runs in your browser. No server, no upload, no API call. Your API responses, config files, and accidentally-committed secrets stay on your machine.
Questions
Is a JSON formatter the same as a beautifier?
Same thing, two names. Both take cramped, single-line JSON and lay it out with indentation so you can read it. If a site calls it a beautifier or a pretty-printer, it's doing what this does.
How do I minify JSON?
Hit Minify. It strips every space, newline, and indent, leaving the smallest valid JSON that says the same thing. Format to read it, minify to ship it through a query string or a request body.
Why does it say my JSON is invalid?
Usually a trailing comma, a single quote where a double belongs, or an unquoted key. JavaScript allows those; JSON doesn't. The error is your browser's own parser message, which in Chrome and Firefox usually names the line and column.
What's the difference between JSON and a JavaScript object?
JSON is a text format; a JavaScript object is a thing in memory. JSON is stricter: double-quoted keys, no trailing commas, no functions, no comments. They look alike, which is exactly why valid-looking JSON sometimes isn't.