GraphQL Formatter

How to use

1. 1Paste a GraphQL document (query, mutation, subscription, fragment, or full SDL schema) into the input area.
2. 2Pick a mode. Format pretty-prints with one selection per line; Minify produces a single-line transport form; Validate runs the tokenizer and bracket-balance check without changing the output.
3. 3In Format mode, choose 2 or 4 spaces of indent to match your codebase style.
4. 4Use Load sample query or Load minified sample to see the formatter expand a compact query, or Clear input to start fresh.
5. 5Click Copy on the output panel to copy the formatted, minified, or validated text. Errors include the line and column so you can fix them quickly.

About this tool

GraphQL Formatter is a browser-based pretty-printer, minifier, and validator for GraphQL documents. Paste a query, mutation, subscription, fragment, or full SDL schema and the tool tokenizes the source against the GraphQL specification's lexical grammar, then re-emits the tokens with consistent indentation, single spaces between identifiers, no trailing commas, and one blank line between top-level definitions. The format mode produces output that matches the conventions used by graphql-js prettyPrint and the Prettier GraphQL plugin: selection sets open at the end of the parent line, each field or fragment spread sits on its own line indented by 2 or 4 spaces (your choice), argument lists wrap when there are two or more arguments or when an argument value is itself multi-line, object and list literals expand the same way, and triple-quoted block string descriptions are re-indented so they align with their surrounding scope. The minify mode strips every non-significant whitespace character, joins the document onto a single line, drops line comments (because they end at a newline and would be lost anyway), and inserts the minimum spacing required to keep adjacent Name, Int, and Float tokens from merging into one token, producing the compact form most often used for HTTP transport. The validate mode runs the same tokenizer and a single-pass bracket balance check; it reports the first unterminated block string, unterminated string literal, unexpected character, leading zero, or mismatched bracket along with the source line and column so you can jump straight to the issue. The tokenizer covers names, variables ($name), directives (@name), Int and Float literals (including exponent and sign rules), single-quoted strings with escape sequences and the Unicode escape forms \uXXXX and \u{X+}, block strings with triple quotes and the spec-compliant \""" escape, ellipsis spreads, and every single-character punctuator (! $ & ( ) : = @ [ ] { | } and the insignificant comma). Operation keywords (query, mutation, subscription), fragment, on, the type system keywords (type, interface, union, enum, input, scalar, schema, directive, extend, implements, repeatable), and the literals true, false, null are lexed as Names because GraphQL is keyword-light by design. Everything runs in your browser; the query or schema you paste here is never uploaded to a server.

Free to use. Works in your browser. No signup, no login.