GraphQL Query Tester

# What is a GraphQL Query Tester?

A GraphQL query tester lets you write GraphQL documents and send them to a real GraphQL endpoint to see the live response. GraphQL is a query language and runtime developed by Meta that lets clients request exactly the fields they need from an API — no over-fetching or under-fetching. Instead of multiple REST endpoints, a GraphQL API exposes a single endpoint that accepts query, mutation, and subscription operations.

This tool validates your GraphQL syntax in the browser before anything is sent, then forwards the request through our server to bypass CORS restrictions — so you can test public and development GraphQL APIs with variables, headers, and authentication, then inspect the formatted JSON response, headers, status code, and timing.

# How to Use

1. Enter the endpoint URL — Paste the full GraphQL API URL (for example https://countries.trevorblades.com/) into the Endpoint field.
2. Write your query — Paste or type a GraphQL operation in the Query box. Use Valid Example to load a working query, or Invalid Example to see how broken syntax is caught before sending.
3. Add variables and operation name — If your query declares $variables, provide them as a JSON object and set the operation name so the server knows which operation to run.
4. Add headers — Click + Add Header for things like Authorization: Bearer <token> on protected endpoints.
5. Click Send Query — The query is validated locally, sent through our proxy, and the response appears on the right with status, headers, size, and duration.

# Frequently Asked Questions