JSON Validator & Formatter
Json Diff
Compare two JSON objects and see differences highlighted. Detect added, removed, and modified values. Perfect for API debugging. Free and private.
Json Schema Validator
Validate JSON data against JSON Schema. Supports draft-07, draft-2019-09, and draft-2020-12. Detailed error messages. Free and private.
Json Validator
Validate JSON syntax instantly in your browser. Check for errors, view detailed error messages with line numbers. Free, fast, no uploads required.
Json Path Tester
Test JSONPath expressions with live results. Extract data from JSON using path queries. See matches highlighted, test filters and wildcards.
JSON Validation and Schema Checking
JSON (JavaScript Object Notation) is the dominant format for web APIs, configuration files, and data storage. Valid JSON follows strict syntax rules, and schema validation ensures data has the correct structure and types.
JSON Syntax Requirements
Valid JSON requires: double quotes for strings (not single quotes), no trailing commas, no comments, properly nested brackets and braces. Common errors include missing commas between elements, unquoted keys, and unterminated strings.
JSON Schema Validation
JSON Schema defines the expected structure of JSON data: required fields, data types, value constraints, and nested object structures. Schema validation catches errors that syntax checking misses—like a required "email" field being absent or an "age" field containing a string instead of a number.
Debugging Invalid JSON
When JSON fails to parse, the error message usually indicates where parsing stopped. Look for: missing or extra commas, unclosed quotes or brackets, special characters that need escaping. Our validator highlights the exact error location.
JSON Diff Comparison
Comparing JSON documents helps identify changes between API versions, configuration updates, or data migrations. Semantic diff (comparing structure, not formatting) catches meaningful changes while ignoring whitespace and key ordering differences.