GQL Parser Online

This GraphQL parser tool is designed for developers who design, test, and debug GraphQL operations. It accepts a query string, optional schema SDL, and optional variables, then produces an AST, performs syntax checks, and shows parsing results in a concise, machine-readable format. When a schema is provided, the tool validates the query against the schema and reports exact field locations, types, and rule violations, enabling targeted fixes.

Conceptually, the tool follows a query-first pipeline: parse -> validate (if schema) -> format (optional) -> report. The core logic uses a standard GraphQL parser to create an AST, a validator against the supplied schema, and a printer for consistent formatting. Outputs include a formatted query string, an AST in JSON form, a boolean validity flag, and a structured set of errors with line and column data.

Audience and value: frontend and backend engineers, API teams, QA, and data integrators gain quick feedback during development and debugging. Unique differentiators include offline operation with provided schema, precise error localization, and deterministic formatting presets that reduce review time. Supported edge cases include multi-operation documents, missing operationName, and JSON variables parsing errors, all reported clearly without executing any GraphQL operations.