{ }
DevJSON Formatter.
Validate, indent, minify and diff JSON. Errors highlighted with exact line and column.
Coming soon← Back to catalog
— What it does
Paste JSON and get it formatted with readable indentation. On errors, line and column of the problem are flagged with a clear message. Minify (strip whitespace) or convert to other formats too — all local, nothing uploaded.
— Features
- Indent with 2 or 4 spaces, or tabs
- Minify (strip whitespace and breaks)
- Validator with line + column on error
- Syntax highlighting (dark theme)
- Convert between JSON, YAML, JSONC
- Collapsible tree view for big JSON
— Use cases
- 01Inspect an API response
- 02Paste a webhook payload to understand what arrived
- 03Detect malformed JSON in logs
- 04Convert a YAML config to JSON
- 05Compare two JSONs side by side (diff)
Coming soon
json.util.ar
We're finishing this one. Landing will live at json.util.ar.
Coming soon
— FAQ
Does it work with JSONC (with comments)?
Yes. JSONC is JSON with // and /* */ allowed. We accept it as input and strip comments when exporting strict JSON.
Handles huge JSON?
Yes, up to ~50 MB without slowdown. Beyond that, use a CLI like `jq`.
Does it find syntax errors?
Yes. Trailing commas, unclosed quotes — line and column where the parser breaks are flagged.
Is my JSON uploaded?
No. All processing is in your browser. Close the tab and nothing is stored.