JSON Formatter & Validator
Beautify, validate, and minify JSON instantly in your browser.
How this tool works
Paste your JSON
Drop any JSON string, API response, or config file into the input panel on the left.
Instant validation
The parser checks it as you type and points to the exact position of any syntax error.
Choose your indent
Pick 2 or 4 spaces - the switch applies instantly without re-pasting anything.
Copy the result
Grab the formatted output with one click - nothing was ever sent to a server.
Quick facts
- Category
- Formatters & Beautifiers
- Best for
- Debugging malformed API responses
About this tool
Paste any JSON and get clean, indented output in real time, with syntax validation that points out exactly what’s wrong when the input doesn’t parse. Everything runs client-side, so your data never leaves the browser. Use it to debug API responses, clean up config files, or prep JSON for documentation.
Why use this tool
100% client-side
Parsing and formatting happen in your browser. Nothing you paste is ever uploaded to a server.
Instant feedback
Validation runs live as you type, with the exact error position - no submit button to wait on.
No account required
There’s nothing to sign up for. Open the tool, paste your JSON, and get your result.
Built for real-world JSON
Handles deeply nested objects, large payloads, and trailing-comma errors other tools miss.
Frequently asked questions
No — the parsing and formatting happen locally in your browser’s JavaScript engine, not on a server. That matters in practice because people often paste things here that shouldn’t leave their machine: a production API response with real customer data, an internal config file with connection strings, or an auth token buried in a payload. None of it is transmitted anywhere; it’s the same as opening the text in a local editor.
The validator shows the specific parsing error and its position, most commonly a missing comma, an unclosed bracket, or a trailing comma before a closing brace.
Yes — use the "Minify input" button to collapse your JSON to a single compact line, useful for reducing payload size before sending it over the wire.
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