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{ } JSON Formatter

Paste JSON to format, minify, validate, inspect structure, and copy deterministic summaries for debugging or agent workflows.

JSON checks
  • Strictly parses JSON with the browser parser — no guessy auto-repairs that could change data meaning.
  • Reports typed errors with line and column when the runtime exposes a parse position.
  • Summarizes root type, character counts, node count, nesting depth, top-level keys, or top-level array items.
  • Produces copyable JSON summaries that match the API/MCP-friendly deterministic output contract.
 Runs in your browser
JSON parsing and formatting run locally in your browser. Shared links only include JSON input when you explicitly opt in.
What this tool does
JSON Formatter formats, minifies, validates, and inspects pasted JSON so nested objects, arrays, strings, numbers, booleans, and null values are easier to review.
Why it is useful
Readable JSON makes API debugging, configuration review, webhook troubleshooting, and documentation work faster because structure and syntax errors are visible immediately.
How it works
The tool parses your input with the browser JSON parser. Formatting reprints valid JSON with indentation, minifying removes unnecessary whitespace, and validation reports deterministic parse status plus structural metadata.
Best input
Paste a complete JSON object, array, string, number, boolean, or null value. If the data came from logs or JavaScript, remove comments, trailing commas, and extra text before validating.
Privacy note
Formatting happens in your browser. The pasted JSON is not intentionally sent to Utilito servers by this page.
Important limitation
JSON is strict. JavaScript object literals, comments, undefined values, and trailing commas are not valid JSON.
Quick answers
Can it fix invalid JSON automatically?
It reports parse errors, but it does not guess repairs that could change data meaning.
Is this safe for secrets?
Prefer not to paste secrets into any website. For ordinary API samples and non-sensitive config, local browser processing keeps the work on your device.
API examples
Call the same deterministic core through Utilito’s compact API router. Send only data you intentionally submit to the server-side endpoint.
Try in API playground →Schema →
Format JSON with curl
curl
curl -X POST https://utilito.dev/api/run \
  -H "Content-Type: application/json" \
  -d '{"tool_id":"json-formatter","input":{"input":"{\"messy\":true}","action":"format","indent":2}}'
Format JSON from Node or browser fetch
javascript
const res = await fetch('https://utilito.dev/api/run', {
  method: 'POST',
  headers: { 'Content-Type': 'application/json' },
  body: JSON.stringify({
    tool_id: 'json-formatter',
    input: { input: '{"messy":true}', action: 'format', indent: 2 }
  })
});
const data = await res.json();
console.log(data.result.output);
Format JSON from Python
python
import requests
payload = {
    "tool_id": "json-formatter",
    "input": {"input": "{\"messy\":true}", "action": "format", "indent": 2},
}
print(requests.post("https://utilito.dev/api/run", json=payload).json()["result"]["output"])
Common Use Cases
Clean API responses before debugging
When an API returns minified JSON, format it to make nested objects and arrays easy to inspect.
Prepare config files for documentation
Format configuration files before including them in READMEs or technical docs.
Validate JSON from third-party sources
Quickly check if JSON from external systems is valid before processing it.
Config Formatter Workbench workflow
Move between JSON, YAML, TOML, XML, config conversion, JSON path inspection, and schema validation while keeping snippets local to the browser.
🧾YAML Formatter / Validator⚙️TOML Formatter / Validator🧾XML Formatter⚙️Config Format Converter🎯JSON Path Tester✅JSON Schema Validator
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