JSON Formatter – Format & Beautify JSON Online (Free Tool)
Free online JSON Formatter tool to format, beautify, and prettify your JSON data instantly. Add proper indentation, syntax highlighting, and line breaks to make JSON data easy to read and debug. Perfect for developers working with APIs, configuration files, and JSON responses. All formatting happens locally in your browser ensuring complete privacy. No data is ever sent to external servers.
What is JSON Formatter?
JSON Formatter takes minified, hand-written, or API-response JSON and produces a clean, indented version that is easy to scan and diff. Use it to inspect a payload from your network tab, normalize input before committing to git, or quickly check whether two responses differ in structure or just whitespace. The whole transformation happens in your browser — your data never leaves the page.
Why use this tool?
- Your data stays private — all processing happens locally in the browser
- No telemetry, no tracking pixels, no third-party scripts
- Open-and-go: bookmark the page once and never look for an alternative
- No telemetry on the tokens, payloads, or code you paste in
- Built for developer workflows: copy-friendly output, syntax-aware highlighting where useful
How to use
- Paste your JSON data into the input field above
- Click the "Format" button to beautify your JSON or "Minify" to compress it
- The result will appear in the output area
- Use the copy button to copy the result to your clipboard
Examples
Beautify a one-line API response
Input: {"user":{"id":1,"roles":["admin","editor"]}} Output is rewritten with 2-space indentation, one key per line, so it can be diffed line-by-line in a code review.
Normalize before committing
Paste a config blob copied from a chat thread, format with tabs, and the result matches your team's editorconfig without any local tooling.
Toggle between formatted and minified
Use Format to expand for reading, then Minify to compress for embedding in an HTML data-* attribute or a URL fragment.
Common use cases
- Inspecting REST/GraphQL API responses while debugging
- Diffing two JSON payloads in a code review or pull request
- Cleaning up JSON copied out of a log line or chat message
- Preparing fixtures and seed data for tests
- Embedding compact JSON in an HTML attribute after minifying
Troubleshooting
- Unexpected token error on a valid-looking payload.
- Most often a trailing comma, unquoted key, or single-quoted string. JSON only accepts double quotes and no trailing commas — fix those and reformat.
- Numbers look truncated (e.g. trailing zeros disappear).
- Large integers above 2^53 lose precision when parsed as JavaScript Number. Wrap the value in quotes before parsing so it stays a string.
- Output looks identical to input.
- The input is already canonical at the indentation you chose. Try a different indent setting or use Minify to verify the round-trip.
Frequently Asked Questions
JSON Formatter is an online tool that helps you format and beautify JSON data. It takes compressed or minified JSON and adds proper indentation and line breaks to make it human-readable.
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