JSON Formatter & Validator
FreeFormat, validate, and minify JSON instantly — right in your browser.
Runs entirely in your browser. Nothing you enter is uploaded or stored.
How it works
What does JSON formatting actually do?
It re-indents JSON text so nested objects and arrays are readable, with consistent spacing and line breaks. Minifying does the reverse: it strips all whitespace to produce the smallest possible payload for transmission or storage.
Why does validation matter?
A single misplaced comma or unclosed bracket makes JSON unparseable, and most parsers only report a byte offset, not a clear reason. This tool converts that offset into a line and column and describes the problem in plain language, so you can find and fix the issue directly in your editor.
Does this tool store or upload my JSON anywhere?
No. Parsing and formatting run entirely in your browser using JavaScript — for very large files, in a background Web Worker so the page stays responsive. Nothing you paste here is sent to a server, logged, or saved.
When would I use this?
Common cases: cleaning up a minified API response before reading it, checking a config file or webhook payload for syntax errors, or minifying a JSON payload before shipping it in a request.