Write and execute GraphQL queries against a schema with mock data — no server needed.
The ByteKiln GraphQL Playground uses the official graphql-js library running entirely in your browser. It parses your schema, builds mock resolvers, and executes queries locally.
Your SDL is parsed with buildSchema() from graphql-js. Syntax errors are highlighted immediately. The type explorer lists all object types and their fields on the Types tab.
The tool walks each query field's return type recursively and assigns mock values based on the GraphQL scalar type. This produces a valid response that matches your schema structure without any real data.
Queries are executed by graphql-js's built-in executor with the mock root value. The JSON response is displayed with full formatting. Ctrl+Enter triggers execution from any input field.
Short answers for the things developers usually ask before trusting a tool.
No. The playground uses the graphql-js library running entirely in your browser. It parses your schema SDL, automatically generates mock resolvers that return realistic-looking fake data, and executes your query locally. No network request is made.
Full GraphQL SDL is supported — type definitions, interfaces, unions, enums, scalars, input types, and directives. The schema is parsed by the official graphql-js library, so any valid GraphQL SDL works.
The tool inspects each field's type and returns a sensible mock value: strings get "Lorem ipsum", integers get 42, booleans get true, IDs get "1", lists return a single-item array, and nested objects are recursively mocked up to a depth of 4.
The cURL export generates a ready-to-paste terminal command that sends your query to a real GraphQL endpoint. Replace the placeholder URL with your actual API and add any auth headers needed.
Yes. Enter a JSON object in the Variables panel. The playground passes these to the graphql-js executor so you can test parameterized queries with $variableName syntax.
Useful follow-ups when one conversion usually turns into three more.
Generate realistic fake JSON data from a JSON Schema, OpenAPI 3.x spec, or a sample JSON object shape.
Format, validate, and minify JSON instantly with a browser-first editor.
Run SQL queries against an in-browser SQLite database. Paste your schema, seed data, and query — instant results.