A concise guide to identify and fix common validation issues when working with JSON Schema.
Practical steps and tips for diagnosing schema mismatches, type errors, and incorrect constraints.
Common causes
Validation errors typically arise from type mismatches, missing required properties, unexpected additional properties, or incorrect patterns and formats defined in the schema.
Step-by-step approach
Start by reading the validator's error message, locate the JSON path it references, and compare the actual data against the schema rules. Validate small fragments of data incrementally and use online validators to isolate problems.
Tools and tips
Use language-specific validator libraries, enable verbose error output when available, write unit tests for critical schemas, and maintain clear schema documentation to reduce future errors.