GraphQL Playground & Query Tester

A GraphQL Playground (also known as a GraphQL Query Tester, GraphQL API Explorer, or GraphQL Client Online) is an interactive, browser-based development workspace for authoring, validating, executing, and debugging GraphQL operations against any HTTP endpoint.

Unlike REST APIs that distribute data across numerous individual URL endpoints with fixed payloads, a GraphQL API exposes a single HTTP POST endpoint backed by a strongly typed schema. Clients query exactly the fields they need, traverse nested relations in a single network round-trip, and submit variables and authentication headers seamlessly.

ToolMono's GraphQL editor combines the developer ergonomics of Monaco Editor with AST validation:

When you click Load Schema, the playground sends an introspection query to retrieve the API's complete type system:

• Queries Tab: Lists all available root query fields with arguments, return types, and descriptions.
• Mutations Tab: Lists write operations, input object types, and payload fields.
• Types Tab: Explores all Object, Interface, Union, Enum, Scalar, and Input Object definitions.
• Add to Query: Click any field button in the explorer to insert a valid field selection directly into your editor.

When exploring large schemas, the Schema Explorer provides real-time search across all types, fields, and descriptions. Clicking Add to Query automatically appends the field with its required arguments to your current query document.

Standardize and export your GraphQL requests:

• Format: Automatically formats GraphQL AST with clean indentation, preserving comments and fragments.
• Minify: Compresses query documents into single-line strings suitable for payload transport.
• Copy cURL: Generates an RFC-compliant cURL command containing your endpoint, query, variables, and headers.

Querying the public Countries GraphQL API:

query GetCountryInfo($code: ID!) {
  country(code: $code) {
    name
    capital
    currency
    emoji
  }
}

Variables:

{ "code": "US" }

Successful Response:

{
  "data": {
    "country": {
      "name": "United States",
      "capital": "Washington, D.C.",
      "currency": "USD",
      "emoji": "🇺🇸"
    }
  }
}