Online GraphQL Schema Viewer & SDL Inspector

Open, inspect, and analyze GraphQL Schema Definition Language (.graphql, .gql) files in your browser. Root query audits, type hierarchy exploration, input validation, and 100% in-memory client privacy.

ecommerce-schema.graphql6 types detected
QueryOBJECT
  • user(id: ID!): User
  • products(limit, category): [Product!]!
  • orders(status): [Order!]!
MutationOBJECT
  • createProduct(input): Product!
  • updateOrderStatus(orderId, status): Order!
UserOBJECT
  • id: ID!
  • name: String!
  • email: String!
  • role: UserRole!
  • orders: [Order!]!
ProductOBJECT
  • id: ID!
  • title: String!
  • priceUsd: Float!
  • inventory: Int!
  • category: ProductCategory!
OrderOBJECT
  • id: ID!
  • buyer: User!
  • items: [Product!]!
  • totalAmount: Float!
  • status: OrderStatus!
OrderStatusENUM
PENDINGPROCESSINGSHIPPEDDELIVEREDCANCELLED

The Complete Guide to GraphQL Schema Definition Language (SDL) & API Type Design

GraphQL is an open-source query language for APIs and a runtime for fulfilling those queries with your existing data. Developed by Meta and maintained by the GraphQL Foundation, GraphQL allows client applications to request precisely the data fields they require, preventing over-fetching and under-fetching.

A GraphQL API is defined by its Schema Definition Language (SDL), specifying strictly typed object types, fields, scalar primitives (String, Int, Float, Boolean, ID), relationships, and execution arguments. The HiFi Toolkit Online GraphQL Schema Viewer parses these definitions into interactive cards, making API documentation and schema reviews fast and intuitive.

Core GraphQL Type System Primitives

1. Query: Root entry point defining read operations for fetching entities and lists.
2. Mutation: Root entry point for write, update, and delete side-effects.
3. Subscription: Real-time event streams delivered via WebSocket protocols.

How to View and Inspect GraphQL Schemas Online

  1. Upload File: Click Open GraphQL Schema or paste your .graphql SDL code.
  2. Browse Types: Switch to Types Overview to inspect fields, arguments, and enums.
  3. Copy Schema: Use the copy button to export clean SDL code for your project.

Frequently Asked Questions (FAQs)

An online GraphQL Schema Viewer is a developer tool that parses, formats, and inspects GraphQL Schema Definition Language (.graphql, .gql) files. It visualizes root entry points (Query, Mutation, Subscription), custom Object types, Enums, Interfaces, and Input types in an intuitive visual dashboard.

GraphQL SDL (Schema Definition Language) is the human-readable text syntax for defining types and fields, while Introspection JSON is the machine-readable payload generated by executing '__schema' queries against a running GraphQL server endpoint.

Yes, 100% private. All GraphQL schema parsing and type inspection run locally in your web browser memory without transmitting API schemas to external servers.