JSON Formatter & Validator
Checked and verified · August 15, 2026
Paste messy or minified JSON and get it pretty-printed, validated, and clearly pointed at the exact error if it doesn't parse. Runs entirely in your browser — nothing is uploaded.
Indent width
For any feedback, bug report and request:
Contact UsHow it works
- Paste your JSON into the box.
- Click Format to pretty-print it with your chosen indent width, or Minify to strip all whitespace down to one line.
- If it doesn't parse, the exact line and character position of the problem is shown so you can find it fast.
- Copy the result or download it as a .json file.
Frequently asked questions
Does this send my JSON anywhere?
No — parsing, validating, and formatting all happen locally in your browser using the standard JSON parser. Nothing is uploaded.
What happens if my JSON is invalid?
You get a plain-language error with the line and column where parsing failed, instead of just "Unexpected token" with no context.
Can I convert compact JSON to pretty-printed, or the reverse?
Yes — Format pretty-prints with 2 or 4-space indenting (your choice), and Minify strips it back down to the smallest valid single-line form.
Does it support JSON with comments (JSON5/JSONC)?
No — this validates against strict JSON (what JSON.parse accepts), the same format almost every API and config file actually requires. Comments or trailing commas will be flagged as errors.
Is there a size limit?
No hard limit — very large payloads (multiple megabytes) may take a moment to format, same as any browser-based tool.
Your files are never uploaded. Gotool.xyz runs entirely as JavaScript in your browser. Your files are processed in memory and never touch a server — nothing to breach, nothing to clean up. Close the tab and it's like it never happened. The only thing we count is which tool ran (just the name, e.g. "merge") so we know what people find useful — never your file, its name, its size, or anything in it.
