Validate Structured Data

Check JSON/XML validity with line-column diagnostics and reusable samples.

Validate JSON, XML, YAML & CSV in your browser

Catch syntax errors before they reach production. Paste JSON, XML, YAML, or CSV and the validator tells you immediately whether it is well-formed. When something is wrong, it points to the exact line and column — malformed JSON, broken XML tags, bad YAML indentation, or a CSV row with the wrong number of columns.

Validation runs 100% client-side, so sensitive payloads never leave your machine. It is free, needs no account, and works offline once loaded.

What does "valid" mean here?

It means the input is well-formed for its format — it parses cleanly. This is a syntax check, not schema validation against a specific contract.