JSON Formatter
Format, minify, validate, sort keys, stringify, and convert JSON Lines.
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Format, minify, and validate JSON
JSON Formatter helps developers clean up API responses, configuration files, and logs. Paste JSON to indent, minify, and locate syntax problems before copying the cleaned result.
Useful For
- Format API response JSON
- Minify JSON for configs or transport
- Find syntax errors in pasted JSON
Good To Know
Do not share JSON containing tokens, passwords, personal data, or private URLs.
Developer Check
Generated code, regexes, meta tags, and config snippets should be treated as drafts and tested again in your runtime, security policy, and deployment environment.
How It Works
Inputs are calculated or converted in the browser whenever possible. Compare important results with the original source before using them. Reviewed on Jul 2, 2026.
Validate JSON safely
Input
- Paste the API response or config exactly
- Mask tokens and personal data before sharing
- For logs, inspect the object around the error instead of pasting the entire file
Validate
- Check parse errors, missing commas, and bracket balance
- Compare values before and after formatting
- Look for common issues such as quotes inside strings, line breaks, and trailing commas
Use
- Choose indentation or minified output before copying
- Re-test production configs in the real runtime
- Sorted JSON is easier to read, but avoid relying on key order in systems that do not guarantee it
Large data
- For multi-MB responses, inspect a smaller slice first
- If the browser slows down, keep the original in a separate file before refreshing
- Re-validate bulk conversions in project scripts or a dedicated pipeline
Before sharing
- Search for API keys, session tokens, emails, and phone numbers
- Replace customer data with anonymous samples in examples
- When pasting into docs or issues, separate formatted output from the original source
When parsing fails, the tool uses the browser's error message to help locate the likely problem area.
Processing runs in browser memory, so very large logs or API responses can be slow. Inspect smaller slices when needed.
Formatting, minifying, and sorting run in the browser by default, and pasted JSON is not stored on the server.