Validators
Validate JSON, XML, YAML, regex and more.
JSON input
Result
Valid JSON
Validate JSON, XML, YAML, and regex online
Validators checks JSON, XML, and YAML for syntax errors, and lets you test regular expressions live against a sample string — all in one place.
Why use this tool
Four validators in one tool
JSON, XML, YAML syntax checking, plus a live regex tester with match highlighting.
Clear error messages
See exactly what's wrong and roughly where, instead of a generic failure.
Live regex highlighting
Matches are highlighted directly in your test string as you edit the pattern.
No upload required
All validation happens locally in your browser.
How it works
- 1Pick JSON, XML, YAML, or Regex.
- 2Paste your data (or pattern + test string for regex).
- 3Read the validation result or highlighted matches.
Frequently asked questions
Good to know
- JSON/XML/YAML validation uses your browser's own parsers — the same engines that would consume this data in production.
- The regex tester highlights every match against your test string.
- Runs fully in your browser — nothing is uploaded.