JSON
How to Validate JSON
Confirm JSON is syntactically valid and matches a schema before you ship an API payload. FreeToolMate validates locally so sample data is not uploaded.
Steps
- Open the JSON Schema Validator.
- Paste your JSON document (or load a file within the page limits).
- Paste a JSON Schema that describes required fields and types.
- Run validation and fix any reported path errors.
- Optionally pretty-print with JSON Beautify so errors are easier to spot.
Syntax vs schema
Syntax validation catches missing commas, bad quotes, and trailing commas. Schema validation checks structure: required keys, types, enums, and nested objects. Use both when an API contract matters.
Related tools
- JSON Viewer — inspect nested keys as a tree
- JSON Compare — compare two payloads
- JSON Cheat Sheet — common syntax mistakes