JSON Formatter & Validator

Paste JSON to pretty-print, minify or validate. Errors report line and column. Copy or download the result. Built to stay responsive on large documents.

Your file is processed locally in your browser. Nothing is uploaded to a server.

Indent

Input

Output

{
  "name": "ForgeKit",
  "tools": 10,
  "nested": {
    "ok": true,
    "values": [
      1,
      2,
      3
    ]
  }
}

Format, minify, validate

Parsing uses the platform JSON.parse. On success, JSON.stringify pretty-prints with 2- or 4-space indent, or minifies to a single line. On failure, the engine’s position is mapped back to line and column in your original text.

Large documents skip syntax highlighting so the page stays usable. Payloads never leave the browser, which is the point if you are inspecting production responses. Pair with the QR generator only for small public strings — do not encode secrets.

Frequently asked questions

Is my JSON sent to a server?+

No. Parsing, formatting, minifying and validation run entirely in the browser. Use it on confidential payloads without uploading them.

How are errors located?+

When JSON.parse fails, the tool extracts the parser’s position and maps it to line and column in your original text so you can jump to the mistake.

Will huge files freeze the page?+

Formatting is deferred with requestIdle/timeouts for large documents, and syntax highlighting is skipped above a safe size so the UI stays responsive. Extremely large files (tens of MB) are still bound by browser memory.

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