GraphQL Schema Validator
Validate GraphQL schemas with syntax checking, best practices analysis, and schema introspection. Detect errors, get warnings, and visualize your schema structure with detailed statistics.
Click "Validate Schema" to check your GraphQL schema
Recommended Settings
GraphQL Schema Best Practices
- •Use PascalCase for type names (User, Product, Order) and camelCase for field names
- •Add descriptions using triple quotes ("""description""") for types and fields
- •Make fields non-nullable (!) when they should always have a value
- •Use meaningful, descriptive names that clearly indicate purpose
- •Group related types together and organize schema logically
Type Safety & Design Guidelines
- •Prefer specific types over generic ones (use DateTime instead of String for dates)
- •Use enums for fields with a fixed set of possible values
- •Avoid deeply nested types - keep schema relatively flat for better performance
- •Use interfaces for shared fields across multiple types
- •Add @deprecated directive with reason when phasing out fields
Pro Tips
- •This tool validates syntax but doesn't execute against a GraphQL server
- •PascalCase type names and camelCase field names are GraphQL conventions
- •Non-nullable fields (!) are enforced at runtime - use them for required data
- •Schema visualization shows the structure of all parsed types and fields
Most Popular
Validate with best practices check, format with 2-space indentation
When to Use This Tool
Validate GraphQL schemas during development to catch syntax errors early. Check for proper type definitions, field structures, and SDL compliance before implementing resolvers or deploying to production.
Ensure your GraphQL schema is valid and well-structured for automatic documentation tools. Clean, validated schemas produce better API docs and make it easier for frontend developers to understand available queries and mutations.
Run validation as part of CI/CD pipelines to prevent invalid schemas from reaching production. Catch breaking changes, naming convention violations, and missing descriptions before they impact your API consumers.
Experiment with GraphQL SDL syntax and get immediate feedback on errors. Understand type system rules, field definitions, directives, and best practices through real-time validation and suggestions.
How It Works
Paste your GraphQL schema definition (SDL) into the input field
Click 'Validate Schema' to check syntax, structure, and best practices
Review validation results: errors (must fix), warnings (should fix), and suggestions (nice to have)
View parsed schema structure to see all types, fields, and relationships
Check statistics for type counts, field counts, and operation counts
Use 'Format' to auto-prettify your schema with proper indentation
Copy the validated schema or download as a .graphql file
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Frequently Asked Questions
What makes a valid GraphQL schema?
A valid GraphQL schema uses proper SDL (Schema Definition Language) syntax with balanced braces, correct type keywords (type, interface, enum, etc.), and valid field definitions. Types must be properly defined, fields need type annotations, and all references must point to existing types.
How are best practices determined?
Best practices are based on official GraphQL specifications and community conventions: PascalCase for types, camelCase for fields, non-null fields for required data, descriptions for documentation, and consistent naming patterns. These improve API usability and maintainability.
What's the difference between errors and warnings?
Errors are syntax violations that make the schema invalid and must be fixed (missing braces, invalid keywords). Warnings are potential issues that don't break the schema but could cause problems (unusual keywords, deprecated patterns). Best practice suggestions are optional improvements.
Can I validate partial schemas?
Yes! The validator works with partial schemas, though you may see warnings about missing Query/Mutation types or incomplete type definitions. This is useful for validating individual types or experimenting with schema fragments during development.
Does this support custom directives and scalars?
The validator recognizes directive syntax (@directive) and custom scalar declarations. However, it doesn't validate custom directive implementations or scalar value formats - it only checks that the SDL syntax is correct and follows GraphQL conventions.
How does schema visualization work?
Schema visualization parses your SDL and extracts all type definitions (objects, interfaces, enums, etc.) along with their fields. It displays this in a structured, hierarchical view showing type kinds, names, and field signatures for easy review of your schema's structure.