~/tools / JSON Formatter
JSON Formatter
Format (pretty-print), minify, or validate JSON. Processed entirely in your browser — nothing is sent to a server.
Useful for turning a squashed one-line API response or config file into something readable, or the reverse — minifying it to save bandwidth. The validate mode pinpoints syntax errors.
# Use Cases
- Pasting a minified API response from your logs to see its actual structure
- Cleaning up a compressed JSON config file (e.g. package.json) before editing it by hand
- Tracking down exactly where a syntax error is breaking your JSON
# Usage
- Paste your JSON into the text area above.
- Click "Format" for indented, readable JSON, or "Minify" to collapse it to one line.
- Click "Validate" to just check whether the JSON is well-formed.
# FAQ
- Is my JSON sent anywhere?
- No. This tool runs entirely in your browser using JavaScript's JSON.parse/JSON.stringify — nothing is sent to a server.
- What happens with invalid JSON?
- The error message shows what JSON.parse detected as the problem. Missing/extra commas and unclosed quotes are the most common causes.
# Related
# Learn more on our sister sites
- Learn JavaScript
Learn by running it in your browser — prodou.net
- Learn Python
Learn by running it in your browser — prodou.net