JSON to GraphQL Converter – Free Online Tool
Convert JSON to GraphQL schema, queries, and input types instantly. Free, private, and runs entirely in your browser.
Tool Interface
Paste JSON and instantly get a GraphQL schema (SDL), a ready-to-run query, or input types for mutations. Type inference handles nested objects, arrays, IDs and nulls.
How it works
- Paste JSON (an object or an array of objects) or load the sample.
- Pick an output mode: Schema generates SDL type definitions, Query generates a selection set over every field, Input generates input types for mutations.
- Copy or download the result as a .graphql file.
- Fields named id (or ending in Id) become the ID scalar; integers become Int, decimals Float.
- Nested objects become nested types; arrays become list types. Nulls are treated as nullable Strings.
100% private — everything runs in your browser, nothing is uploaded.
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About This Tool
JSON to GraphQL Converter – Free Online Tool
Building a GraphQL API or writing queries by hand means translating every JSON object into type definitions, selection sets, and input types — a slow, error-prone chore. The JSON to GraphQL Converter by Trencada does it for you: paste any JSON object (or array of objects) and instantly get a GraphQL schema (SDL), a ready-to-run query, or input types for mutations. Type inference is automatic, nested structures become nested types, and everything runs entirely in your browser — your data never leaves your device.
How to Convert JSON to GraphQL
- Add your JSON: Paste your JSON into the "JSON input" box, or click "Load sample" to fill in a ready-made example.
- Pick an output mode: Choose GraphQL Schema (SDL) for type definitions, GraphQL Query for a ready-to-run selection set, or GraphQL Input Types for mutation inputs.
- Set the root name and convert: Adjust the "Root type / field name" (default "User"), then click "Convert".
- Copy or download: Copy the generated GraphQL to your clipboard, or click "Download .graphql" to save it as
schema.graphql. Click "Reset" to start over.
Key Features
- Three output modes: GraphQL Schema (SDL), GraphQL Query, and GraphQL Input Types
- Automatic type inference: integers → Int, decimals → Float, text → String, true/false → Boolean
- Fields named
id(or ending in_id/Id) are typed as GraphQLID - Nested objects become nested types; arrays become list types
- Null values become nullable String fields
- Customizable root type / field name
- One-click sample JSON to try the tool instantly
- Copy to clipboard or download as
schema.graphql - 100% client-side processing — your data never leaves your browser
- Free to use, no account or signup required
Why Choose Trencada?
The JSON to GraphQL Converter is part of Trencada's free Developer & Encoding Tools collection. Every Trencada tool runs directly in your browser: no file uploads, no waiting, no accounts, and no watermarks. Your data stays private on your own device, conversions are instant, and the interface works on desktop and mobile. Whether you are designing a GraphQL API, writing client queries, or learning GraphQL, Trencada gives you a fast, private, dependable conversion workflow.
Related Data and Developer Tools
If you work with JSON and APIs, these Trencada tools may also be useful:
- JSON Formatter – Validate and neatly format JSON before converting it.
- JSON to CSV – Turn JSON into spreadsheet-ready CSV tables.
- JSON to TypeScript Converter – Generate TypeScript interfaces from JSON.
- YAML to JSON – Convert YAML data into JSON first.
- Timestamp Converter – Decode Unix timestamps found inside JSON data.
- Character Counter – Count characters in your generated output.
- Find & Replace Tool – Bulk-replace values across text.
- Text Case Converter – Fix the letter casing of field names.
Frequently Asked Questions
What does the JSON to GraphQL Converter do?
It converts JSON data into GraphQL code. Depending on the output mode you choose, you get a GraphQL schema in SDL (type definitions), a ready-to-run query with a selection set, or input types for use in mutations.
What is GraphQL SDL?
SDL (Schema Definition Language) is the standard text format for describing a GraphQL API's types, e.g. type User { id: ID name: String }. The tool generates valid SDL directly from your JSON structure.
How does the tool infer GraphQL types?
Integers become Int, decimal numbers become Float, text becomes String, true/false become Boolean, and null values become nullable String. Fields named id (or ending in _id / Id) are typed as GraphQL ID.
What happens to nested objects and arrays?
Nested objects become nested GraphQL types (for example, a user object produces a User type), and arrays become list types such as [String] or [User].
Is my JSON uploaded to a server?
No. The conversion runs entirely in your browser using JavaScript — your JSON is never sent to Trencada or any third party, and no copy is stored.
What file do I get when I download?
Clicking "Download .graphql" saves the generated output as schema.graphql, which you can open in any code editor or paste into your GraphQL project.
Is the JSON to GraphQL Converter free?
Yes. The JSON to GraphQL Converter on Trencada is free to use, with no signup required.