Does FixTools validate and format at the same time?

Yes. When you click Format, FixTools first checks if the JSON is syntactically valid, then formats it. Invalid JSON shows an error message instead of a formatted output.

What kind of JSON errors does the validator catch?

The validator catches all JSON syntax errors: missing commas, trailing commas, unquoted keys, single quotes instead of double quotes, mismatched brackets, and more.

Can I validate without formatting?

Yes. Use the dedicated JSON Validator tool if you only want to check validity without reformatting the layout.

Browse tools

Free · Fast · Privacy-first

JSON Formatter and Validator

Formatting JSON and validating it should happen together — there is no point beautifying invalid JSON. FixTools formats and validates in a single step: it checks for syntax errors and pretty prints your JSON simultaneously, highlighting any problems it finds.

⚡ Use Tool Now How it works

Cost: Free forever
Sign-up: Not required
Processing: In your browser
Privacy: Files stay local

⚡

Format and validate in one step

🔒

Highlights exact error location

✨

Explains what went wrong

JSON Tool

JSON Formatter

All processing happens in your browser — your files are never uploaded to any server.

🚀Open JSON Formatter

100% Free · No account · Works on any device

How to use this tool

💡

Paste your JSON and click Format. Any syntax errors are highlighted with an explanation; valid JSON is formatted and displayed.

How It Works

Step-by-step guide to json formatter and validator:

1
Paste your JSON
Paste the JSON you want to validate and format into the editor.
2
Click Format
FixTools validates the JSON first. If errors exist, they are highlighted. If valid, the JSON is formatted immediately.
3
Fix errors or copy output
If errors are found, the error message tells you the line and position. Fix and reformat. If valid, copy the formatted result.