GraphQL Schema Validator

Paste your GraphQL Schema into the box above and the result appears instantly below — nothing to press, nothing to upload. It runs entirely in your browser, so it is fast and private, and you can copy the output or download it as a file.

Yes. It is completely free with no signup or limits, and it is private because everything happens locally in your browser — your code is never sent to a server. That makes it safe for proprietary or unreleased code, and it keeps working offline once the page has loaded.

It checks your GraphQL Schema for syntax errors and reports whether it is valid, pointing to the problem if it is not. Catching a syntax error early saves debugging time later.

Valid GraphQL Schema is input that parses without a syntax error according to the GraphQL Schema specification. This tool parses your input the same way a real GraphQL Schema processor would; if it parses cleanly it reports success, and if not it shows the error message so you can find and fix the problem.

There is no fixed limit because nothing is uploaded — the only constraint is your device's memory, so even large files process quickly on a normal computer. The engine loads on first use and is cached afterwards, so repeat runs are instant.

Yes. It runs in any modern browser on Windows, Mac, Linux, iPhone and Android with nothing to install, and works offline once loaded. The result can be copied or downloaded on any device.