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json formatter

Clean up and validate JSON, instantly.

Paste messy or minified JSON on the left. It formats, validates, and highlights errors as you go — nothing leaves your browser.

Input
Output
Formatted JSON will appear here.
Waiting for input
Everything runs locally in your browser — your JSON is never sent to a server, so it's safe to paste sensitive data (API responses, config files, etc).
Frequently asked questions
No. All formatting and validation happens directly in your browser using JavaScript — nothing you paste is sent to a server, logged, or stored. Safe to use with real API responses, config files, or other sensitive data.
Format pretty-prints your JSON with indentation and line breaks so it's easy to read. Minify does the opposite — strips all whitespace into a single compact line, which is what you'd typically send over a network or store to save space.
The most common causes: a trailing comma after the last item in an object or array (valid in JavaScript objects, but not valid JSON), using single quotes instead of double quotes around strings, or a missing comma between items. The error message shows the exact line and column where parsing failed — start there.
Yes — use the dropdown next to the Format button to switch between 2 spaces, 4 spaces, or tabs.
No — this checks that your JSON is syntactically valid (correctly structured), not that it matches a specific schema or shape. For schema validation, you'd need a schema-aware tool that checks field names, types, and required fields against a defined structure.