Validate JSON & YAML

Check if your JSON or YAML is valid. Get detailed error messages with line numbers. Free, runs in your browser.

Free No signup Files stay on your device Instant

Drag & drop your file here, or click to browse

Accepts JSON, YAML, YML

Done!

How to Validate JSON & YAML

1

Paste or upload JSON

Paste your JSON text or upload a .json file.
2

See validation result

Instantly see if your JSON is valid. Errors show the exact line and character position.
3

Fix and re-validate

Edit your JSON directly and re-validate until it passes.

How do I validate JSON?

Paste your JSON or upload a file. The validator instantly checks for syntax errors and shows the exact error location.

Does this validate YAML too?

Yes. Upload a .yaml or .yml file, or paste YAML text. The validator checks for proper YAML syntax including indentation issues.

What errors does it detect?

Missing commas, unclosed brackets, invalid escape sequences, duplicate keys, and malformed strings. Error messages include exact line numbers.

Is my data safe?

Yes. Validation runs entirely in your browser using built-in JSON.parse() and js-yaml. Your data never leaves your device.

Can I fix errors directly?

Yes. Edit your JSON or YAML in the text area and re-validate instantly until all errors are resolved.

Check if your JSON or YAML is valid. Get detailed error messages with line numbers. Free, runs in your browser.