How to Validate JSON Before Shipping an API Integration

Start With Syntax

Before you look at business rules, make sure the payload is valid JSON. Invalid syntax blocks every downstream check.

Then Check Structure

Once syntax passes, compare the payload shape against what your API or schema expects:

• Required fields
• Value types
• Null handling
• Array item structure

Good Team Habits

• Keep sample payloads in version control
• Validate fixtures in tests
• Use schema validation for shared contracts

Try JSON Validator for raw syntax checks and JSON Schema Validator for structure validation.