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JavaScript Tools

Beautify, minify, validate, obfuscate, escape and run JavaScript and TypeScript, plus tools for React, Vue and API testing.

API Tester (REST Client) Send GET, POST, PUT, PATCH and DELETE requests to REST APIs from your browser and inspect status, headers and pretty-printed JSON. Babel Formatter Format modern JavaScript and JSX using the Babel parser and Prettier. Flow Formatter Format JavaScript with Flow type annotations online using the Flow parser. GraphQL to TypeScript Generate TypeScript interfaces, enums and union types from a GraphQL schema (SDL), with nullability and argument types. HTML to JSX Converter Convert HTML markup to valid JSX for React: className, htmlFor, style objects, self-closing tags and comments handled automatically. JavaScript Escape JavaScript escape online: convert special characters into escape sequences so text is safe inside JavaScript. JavaScript Formatter Beautify or minify JavaScript online: fix indentation, spacing and line breaks of messy or minified JS code. JavaScript Key Code Finder Press any key to see its event.key, event.code, legacy keyCode, location and modifier state for JavaScript keyboard handlers. JavaScript Minifier Minify JavaScript online with Terser to shrink file size for faster websites. JavaScript Obfuscator Make JavaScript harder to read and copy by renaming variables and encoding strings. JavaScript Pretty Print Opinionated JavaScript pretty print with Prettier: identical output for any input layout, with indent, width, semicolon and quote options. JavaScript Tester Run JavaScript online and see console.log, warnings, errors and tables instantly in a safe, sandboxed browser console. JavaScript Unescape JavaScript unescape online: turn escaped sequences back into readable plain text instantly. JavaScript Validator Check JavaScript for syntax errors online and find the exact line and column of each problem. JSON Schema to TypeScript Turn JSON Schema into TypeScript interfaces and types with optional properties, enums, $ref definitions and JSDoc comments. JSON to Mongoose Schema Generate a Mongoose schema and model from a sample JSON document, detecting Date, ObjectId, arrays and nested objects. JSON to Zod Schema Generate a Zod validation schema for TypeScript from a JSON sample. React JSX Formatter Format React components and JSX online with Prettier. Regex Cheat Sheet Interactive regex cheat sheet: anchors, classes, quantifiers, groups, lookarounds, flags and Unicode, with clickable examples and a flavour table. Regex Explainer Break a regular expression into tokens and explain each part in plain English: groups, quantifiers, classes, anchors and lookarounds. Regex Tester Test JavaScript regular expressions live: highlight matches, inspect capture groups and named groups, try flags and preview replacements. SRI Hash Generator Generate Subresource Integrity (SRI) sha384 hashes and ready-to-paste <script> or <link> tags with integrity and crossorigin attributes. SVG to JSX / React Component Turn SVG markup into a React component: camelCase attributes, className, style objects and {...props}, with optional TypeScript. SVG to React Native Convert SVG files into react-native-svg components (Svg, Path, G, Circle…) ready to paste into your React Native app. TypeScript Formatter Format TypeScript code online with Prettier, including interfaces, generics, decorators and type annotations. Vue Formatter Format Vue single-file components: template, script and style blocks in one pass.

JavaScript tools for everyday front-end and Node.js work

JavaScript powers almost every website and a large share of back-end services. Code arrives minified, pasted from Stack Overflow, generated by bundlers or written in TypeScript and JSX. These JavaScript tools help you make it readable, check it, shrink it for production and run snippets quickly without setting up a project.

Which JavaScript tool should you use?

  • Readable code – the JavaScript formatter applies consistent Prettier-style formatting; TypeScript formatter and React formatter handle types and JSX.
  • Syntax check – the JavaScript validator parses code and reports errors with line numbers without running it.
  • Run code – the JavaScript tester executes snippets in a sandboxed console with logs, tables and error messages.
  • Production size – JS minify removes whitespace and shortens code for faster loading.
  • Protect client code – the JavaScript obfuscator makes code harder to read, which deters casual copying (it is not encryption).
  • Strings – JavaScript escape safely embeds text with quotes and newlines in string literals.
  • React markup – HTML to JSX converts HTML templates into JSX.
  • APIs – the API tester sends HTTP requests from the browser, and cURL to JavaScript turns curl commands into fetch() code.

Typical workflows

Debugging a minified bundle: format it to get readable structure, search for the function name from the stack trace, and test a suspect piece in the JavaScript tester.

Preparing a snippet for a blog post: format it, check it with the validator, run it once in the tester to make sure the example output is correct, then create highlighted HTML with the code highlighter.

Typing an API: fetch a sample response, then generate TypeScript interfaces or Zod schemas with the JSON to TypeScript and JSON to Zod generators.

JavaScript, TypeScript and frameworks

TypeScript adds static types to JavaScript and compiles to plain JavaScript; JSX is the HTML-like syntax used by React; Vue single-file components combine template, script and style. Each needs a formatter that understands its syntax, which is why this category has separate formatters for them rather than one generic tool. The Babel and Flow formatters cover projects that use those toolchains.

Tips

  • Format and validate before committing; consistent formatting keeps code review focused on logic.
  • Minification is not a security measure. Anything shipped to the browser can be read; never embed secrets in front-end code.
  • The browser sandbox has no Node.js APIs, so test fs or process code locally.
  • Code you paste is processed in your browser and not uploaded.

Frequently asked questions

Can I run JavaScript online safely?
Yes. The JavaScript tester runs code in a sandboxed iframe with its own origin, so it cannot access this website, your cookies or other tabs.
Does minifying JavaScript make it secure?
No. Minified code can be formatted and read again. It only reduces file size; use server-side code for anything that must stay secret.
What is the difference between minifying and obfuscating?
Minifying makes code smaller while keeping its logic readable after formatting. Obfuscating deliberately transforms code to be hard to understand, usually making it larger and slightly slower.
Can these tools format TypeScript and JSX?
Yes. There are dedicated formatters for TypeScript, React (JSX), Flow and Vue single-file components.