GraphQL Query Syntax and Field Check Online

This is a GraphQL query syntax check. It is not a full GraphQL executor. It does not run the query against a server.

Schema and query stay in the browser. Analytics and ads may load on the page.

Schema (SDL)

Paste SDL. When a Query type is present, unknown field names are reported with a line number.

Query

How to check a GraphQL query

Paste schema

Use SDL with type Query to test field names.
Paste query

A query, mutation, subscription, or shorthand selection set.
Check

Read syntax or field errors with line numbers.
Try the error sample

Load error sample reports missingField on type User.

Common Use Cases

Selection Set Checks

Find unmatched braces, brackets, or parentheses before you send a query to an API.

Basic Field Review

Compare query field names with Query, Mutation, Subscription, and nested object types in SDL.

Operation Summary

Identify the operation type, optional operation name, variable declarations, and selected fields.

Local Query Drafting

Check a draft schema and query without sending either text to a GraphQL server.

Why this is a syntax check

This page checks balanced braces, brackets, parentheses, operation shape, and selected field names when the SDL defines those types. Errors include a line number. It does not execute the query or provide complete GraphQL validation. Text stays in your browser. Analytics or ads on the page may still load.

FindUtils GraphQL query syntax check reads a query, mutation, subscription, or shorthand selection set. It reports unmatched braces, brackets, and parentheses with line numbers.

When you provide SDL, the checker builds a basic type and field map. It can then report selected fields that do not exist on Query, Mutation, Subscription, or a known nested object type.

The checker runs in your browser and does not send or execute a query. Use the GraphQL Schema Validator for schema-focused checks, or use GraphQL to TypeScript for type generation.

How it compares

A full GraphQL client validates and executes operations with a schema-aware library and server connection. FindUtils gives a fast local shape check, but a passing result does not prove that the operation is valid or executable.

The checker does not validate complete SDL grammar, argument rules, variable types, directives, or fragment behavior. Format JSON variables separately with the JSON Formatter.

GraphQL Check Tips

Put each SDL field on its own line so the basic field checker can read it.
Use this page for query shape checks, not for execution or full GraphQL validation.
Check argument types, required arguments, variables, directives, and fragments with a full GraphQL implementation.
Use the error sample to see how an unknown nested field is reported.
Use the GraphQL Schema Validator when the SDL itself needs a schema-focused check.

Frequently Asked Questions

Does this run the query against a server?

No. FindUtils checks query shape and selected field names in your browser. It does not send the operation to a GraphQL endpoint.

Is this a full GraphQL engine?

No. FindUtils provides a limited syntax and field-name check. It is not a complete GraphQL parser, validator, client, or execution engine.

Does it support fragments?

Fragment support is limited and not a complete implementation. The checker can still report delimiter errors, but a passed result does not validate fragment rules.

Can I paste an introspection result?

No. The field-name checker expects GraphQL SDL, not an introspection JSON result. Convert or obtain SDL before you use schema field checks.

Is there a GraphQL schema validator too?

Yes. Use GraphQL Schema Validator for schema-focused checks. This query tool reads only a limited SDL field map.

Which syntax errors does it find?

It finds unexpected or unclosed braces, brackets, and parentheses. It also reports selected unknown fields when supported SDL type information is available.

Does it validate field arguments and variable types?

No. It reads past variable declarations and balanced argument groups. It does not validate argument names, required values, or variable types.

Does it validate the SDL itself?

No. It reads a limited type and field map from SDL. Use a full schema validator for SDL grammar and complete type-system rules.

Why should SDL fields use separate lines?

The basic SDL reader recognizes field definitions line by line. A compact one-line type can prevent field-name checks while the query shape check still runs.

Does a passed check mean the query will run?

No. A passed result does not test a server, resolvers, permissions, variable values, arguments, directives, or complete fragment behavior. Run complete validation in the target GraphQL stack.

Run it from code

$ curl -X POST \
  api.findutils.com/api/tools/graphql-playground/execute \
  -d '{"schema":"type Query { user: User }\ntype User { name: String }","query":"{ user { name } }"}'

$ claude mcp add findutils \
  --transport http https://mcp.findutils.com/
# then call findutils:graphql_playground

API reference Add to Claude

GraphQL query syntax check