GraphQL Tester: Run Queries & Explore Schemas Online
A GraphQL tester sends queries and mutations to any GraphQL endpoint and shows the JSON response, formatted and timed. Paste the endpoint URL, write your query, add variables as JSON, and send: requests are relayed server-side so CORS never blocks you. One click runs the standard introspection query and lists every query, mutation, and type the schema exposes, like a WSDL analyzer for GraphQL.
{{variable_name}} in fieldsHow it works
- 1
Paste the GraphQL endpoint URL (usually ending in /graphql).
- 2
Write a query or mutation, add variables as JSON and any auth headers, then click Send.
- 3
Click Introspect Schema to list all queries, mutations, and types the API exposes.
Frequently asked questions
How do I test a GraphQL API online?
Enter the endpoint URL, type a query (for example { __typename }), and click Send. The tool POSTs {query, variables} as JSON, the standard GraphQL-over-HTTP transport, and pretty-prints the JSON response with status and timing.
What is GraphQL introspection?
Introspection is a built-in GraphQL feature: a special query (__schema) that returns the API's full type system: every query, mutation, type, and field. The Introspect Schema button runs it and renders the result as a browsable list, so you can discover what an endpoint offers without documentation.
How do I pass variables to a query?
Declare them in the query (query ($id: ID!) { user(id: $id) { name } }) and provide values in the Variables box as JSON ({"id": "42"}). Variables keep queries reusable and avoid string-escaping problems.
Why do I get errors with 200 OK status?
GraphQL returns HTTP 200 even when the query fails; errors are reported in the errors array of the JSON body instead of the status code. Always check the response body, not just the status.
Can I test authenticated GraphQL APIs?
Yes. Add an Authorization header (for example Authorization: Bearer <token>) in the headers box. Headers are relayed as-is to the endpoint and never stored server-side.
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