Free · Runs in your browser

JSON Formatter & Validator

Paste messy JSON, clean it up, or check it for errors. Everything happens on your device — your data is never uploaded.

Your JSON

Indent Sort object keys alphabetically when formatting

Result

Format or minify JSON to see the result.

How to use this

Paste your JSON into the top box.
Open or download a local .json file without uploading it.
Format pretty-prints it with your chosen indent.
Sort keys optionally alphabetizes object keys at every nesting level while preserving duplicate keys and number spelling.
Minify strips whitespace to the smallest valid form.
Validate checks for errors and tells you exactly where they are.
Edit result lets you change the formatted JSON directly. Your edits are synced back to the top box; Preview validates them and restores folding.
Fold or expand nested objects and arrays with the line chevrons, or use Collapse all and Expand all. Copy result still copies the complete JSON.