JSON formatter and validator
Format, minify and validate JSON, jump to the line and column of a syntax error, and browse the result as a tree.
- Runs in your browser
- No upload
- Result stays on your device
Privacy & limitsRuns in your browser. Nothing is uploaded.
Input content stays in this tab; Refentra does not upload or store it. Optional aggregate action counts are sent only with your usage consent. Clear the workspace when finished.
Supported profile: JSON: 20,000 nodes, depth 64. Numbers use IEEE-754; integers must be safe and finite. Numbers must round-trip their decimal meaning. Unsafe integers, overflow, underflow or unsupported decimal precision are rejected before output.
Files: UTF-8 only; an optional UTF-8 BOM is removed on import. Error offsets refer to editor UTF-16 units.
Maximum text: 200,000 UTF-16 units; parser limits can be smaller. Worker time limit: 15 seconds (regex 1.5 seconds).
Check the input and the result
- Prepare and choose the operation
Paste your JSON, then choose formatting with spaces or tabs, or minifying for a compact version.
- Check a concrete example
Use this sample and compare the indicated result: {"b":2,"a":1} → minify → {"b":2,"a":1}
- Check the output before you reuse it
Compare the values and nesting in the tree. Indentation only changes how the JSON looks, not the data it holds.
Answers for this task
Are large integers preserved?
Numbers that can't be represented safely are rejected instead of being rounded without notice. Store identifiers as quoted strings.
What should I check if the input fails?
Remove trailing commas and comments, and put keys and strings in double quotes. Check the position the error reports.
Where does this tool stop?
JSON parsing is capped at 200,000 UTF-16 units, 20,000 nodes and depth 64. It doesn't validate your application’s schema.