1. What does this tool do
This free online JSON beautifier formats, validates, and minifies JSON in one place. Use it to format JSON, pretty print JSON, or minify JSON for APIs and configs. Paste messy or minified JSON and get readable, indented output—or minify for smaller payloads. Free and private; no sign-up, no upload. All processing runs in your browser so your data stays on your device. Ideal for API responses, config files, debugging, or quick fixes.
2. How to use it
Quick start: Paste or type JSON, click Format or Beautify for indented output, or Minify for a single line. Fix any parse errors the tool reports. Copy the result.
- Paste or type JSON — Put your JSON in the input area (e.g. from an API response or a config file).
- Format — Click Format or Beautify. The tool indents and line-breaks the JSON. If parsing fails, fix the reported error.
- Choose indentation — Select 2 or 4 spaces (or tabs if offered) for the formatted output.
- Minify — Use the Minify option to collapse whitespace into one line. Copy the result for APIs or configs.
- Copy — Copy the formatted or minified output with one click.
3. How it works
The tool parses the input with JSON.parse(). If valid, it reformats by adding indentation and newlines (beautify) or removing them (minify). Invalid JSON throws; the tool surfaces the error message and often the position. All processing is client-side in your browser. No data is sent to any server.
4. Use cases & examples
- API responses — Paste a response and read the structure with proper indentation.
- Config files — Reformat JSON configs for readability or minify for deployment.
- Debugging — Validate and pretty-print JSON from logs or exports.
- Quick fix — Find missing commas or quotes using the parser’s error message.
Example
- Input:
{"a":1,"b":2}→ Formatted: indented with newlines. Minified: same string or tighter. - Invalid:
{"a":1,}→ Error: trailing comma or similar; fix and re-run.
5. Limitations & known constraints
- JSON only — Non-JSON (e.g. JSON with comments or trailing commas) may not parse; use a JSON5-capable tool for that.
- Size — Very large JSON may slow the browser or hit memory limits. Split or process in chunks if needed.
- No schema — Validation is syntax-only; the tool does not validate against a JSON Schema.