Developer tools

Generate types, convert markup and format code.

JSON to TypeScript — Generate TypeScript interfaces from a JSON sample.
JSON to Go — Generate Go structs with json tags from a JSON sample.
JSON to Python — Generate Python dataclasses from a JSON sample.
JSON to C# — Generate C# classes for System.Text.Json from a JSON sample.
JSON to Java — Generate Java classes (Jackson + Lombok) from a JSON sample.
JSON to Kotlin — Generate Kotlin data classes (kotlinx.serialization) from a JSON sample.
JSON to Rust — Generate Rust structs with Serde from a JSON sample.
JSON to Swift — Generate Swift Codable structs from a JSON sample.
JSON to Zod schema — Generate Zod schemas with inferred types from a JSON sample.
JSON to JSON Schema — Generate a JSON Schema (draft 2020-12) from a JSON sample.
JSON to GraphQL — Generate GraphQL type definitions from a JSON sample.
JSON to Mongoose schema — Generate Mongoose schemas from a JSON sample.
HTML to JSX — className, htmlFor, style objects and self-closing tags handled for you.
SVG to JSX — Drop SVG icons into React with camelCase attributes.
SVG to React Native — react-native-svg components with the right imports.
CSS to JS object — CSS rules as camelCase JavaScript objects for CSS-in-JS.
cURL to JavaScript fetch — Paste a cURL command, get working JavaScript fetch code.
cURL to Axios — Paste a cURL command, get working Axios code.
cURL to Python requests — Paste a cURL command, get working Python requests code.
Markdown to HTML — GitHub-flavoured Markdown to HTML with a live preview.
HTML to Markdown — Clean Markdown from web pages, emails and CMS exports.
HTML formatter — Beautify messy HTML or minify it for production.
CSS formatter — Beautify or minify stylesheets.
JavaScript formatter — Tidy minified or messy JavaScript and JSON.
SQL formatter — Readable SQL for MySQL, PostgreSQL, SQL Server and more.
Base64 encode / decode — Encode or decode Base64 with full Unicode support.
URL encode / decode — Percent-encode query values or decode encoded links.
HTML entity encode / decode — Escape text for HTML, or turn & entities back into characters.
JWT decoder — Read a token's header and claims, with expiry shown in plain time.
Hash generator — MD5, SHA-1, SHA-256, SHA-384 and SHA-512 checksums.
Unix timestamp converter — Epoch seconds or milliseconds to IST, UTC and local time — and back.
JSON to BigQuery schema — Create a BigQuery table schema (name, type, mode) from a sample JSON row, with RECORD, REPEATED, TIMESTAMP and DATE detected for you.
JSON to Go struct (BSON) — Go structs for the MongoDB driver with bson and json tags, time.Time for ISO dates and primitive.ObjectID for _id.
JSON to JSDoc — JSDoc @typedef and @property comments from a JSON sample — type hints for plain JavaScript and VS Code.
JSON to React PropTypes — PropTypes.shape, arrayOf and isRequired definitions for React components, built from a JSON sample of the props.
JSON to Scala case class — Scala case classes from JSON, with Option[...] = None for null and missing fields.
JSON to io-ts — io-ts runtime codecs (t.type, t.partial, t.array) plus exported TypeScript types, from a JSON sample.
JSON to Flow types — Flow exact object types from a JSON sample, with optional and nullable fields marked.
JSON to MobX-State-Tree — MobX-State-Tree models (types.model, types.array, types.maybeNull) generated from a JSON snapshot.
JSON to MySQL schema — CREATE TABLE statements for MySQL 8 designed from a JSON sample: column types, NOT NULL, and child tables with foreign keys for nested arrays.
JSON to Sarcastic — Runtime type checkers for the sarcastic library (is.shape, is.arrayOf, is.maybe) generated from a JSON sample.
JSON Schema to TypeScript — TypeScript interfaces and union types from a JSON Schema, with descriptions and formats kept as doc comments.
JSON Schema to Zod — Zod schemas with inferred types from a JSON Schema — string formats, min/max and enums become Zod checks.
JSON Schema to OpenAPI — Wrap a JSON Schema in an OpenAPI 3.1 (or 3.0) document, with definitions moved to components.schemas and $refs rewritten.
JSON Schema to Protobuf — proto3 messages from a JSON Schema: repeated fields, nested messages, enums from enum, oneof from oneOf/anyOf and map<string, …> from additionalProperties.
HTML to Pug — Indentation-based Pug templates from HTML: #id and .class shorthand, attributes, inline #[tag] text, comments and script blocks.
CSS to Tailwind — Map CSS declarations to Tailwind utility classes per selector — spacing scale, flex/grid, colours, borders, :hover and media queries included.
CSS to styled-components — Turn plain CSS into styled-components or Emotion template literals, with nested selectors, :hover and media queries moved inside each component.
JavaScript object to JSON — Turn a JavaScript object literal (unquoted keys, single quotes, trailing commas, comments) into strict, valid JSON.
TypeScript to JavaScript — Strip TypeScript types and keep your formatting: interfaces, generics, enums, parameter properties and satisfies are handled.
Flow to JavaScript — Remove Flow type annotations, type imports and // @flow headers, leaving plain JavaScript (JSX kept).
Flow to TypeScript — Best-effort conversion of common Flow syntax to TypeScript: ?Type, exact objects, $ReadOnly, $Keys, mixed, opaque types and casts.
GraphQL to TypeScript — TypeScript types for every GraphQL type, input, enum, interface and union, with Maybe<T> for nullable fields and optional resolver signatures.
GraphQL to introspection JSON — Build the schema and produce its introspection result (schema.json) for code generators, IDEs and Apollo tooling.
GraphQL to Flow — Flow type definitions from a GraphQL schema: exact object types, ?T for nullable fields, string unions for enums.
GraphQL to fragment matcher — The possibleTypes map Apollo Client 3 needs for fragments on interfaces and unions (or the Apollo 2 introspection fragment matcher).