Format JSON Online — Free
Format and beautify JSON online — free, with syntax validation and error reporting. Paste minified or messy JSON and instantly get a properly indented, color-highlighted version. Choose 2-space, 4-space, or tab indentation. The formatter validates as it parses, so syntax errors (missing commas, unclosed braces, trailing commas) are highlighted with line numbers. Runs 100% client-side — your JSON never leaves your browser. Safe for API responses, config files, secrets, and production payloads. No signup, no usage cap, no upload.
How to format json online
- Paste your input (JSON, JWT, CSV, or other text) into the tool above.
- Choose the format/option you need — everything is computed in your browser.
- Copy the result with one click, or download it as a file.
Common use cases
- Debugging API responses and inspecting JWT payloads
- Pretty-printing minified JSON copied from network tabs or logs
- Converting between data formats (CSV ↔ JSON, JSON ↔ YAML)
- Validating syntax before pasting into config files
- Sharing readable snippets with teammates in pull requests
Frequently asked questions
How do I beautify JSON?
Paste it above and the formatter will auto-indent and highlight syntax. Choose your preferred indent width.
How do I validate JSON?
The formatter validates as it parses. Errors show with line/column so you can fix invalid syntax fast.
Can I minify JSON here too?
Yes — see our dedicated minify-json-online page for one-click minification.
Is my JSON sent to a server?
No — formatting and validation happen entirely in your browser. Safe for sensitive payloads.