Everything in the catalog

Write Svelte components in the browser with a live preview and shareable URL.

Edit Vue single-file components and see the compiled result and preview instantly.

An open-source API client for building and testing REST and GraphQL requests, usable in the browser.

Collection of small developer utilities such as encoders, hash generators, converters and calculators, grouped in one app.

Analyses shell scripts online and points out bugs and portability problems.

Searchable viewer that combines documentation for many languages and frameworks, with offline support.

Transpile or minify JavaScript and TypeScript with the SWC compiler and adjustable options.

Packs a local or remote repository into a single AI-friendly file in XML, Markdown, JSON or plain text.

Live Swagger UI demo that lets you load a spec URL and try its endpoints.

Builds an nginx server configuration from form options for performance and security.

Creates README-ready status badges for repositories, builds and downloads.

Interactive demo showing how ReDoc renders an OpenAPI spec as a three-panel API reference.

x86 PC emulator in WebAssembly that boots Linux, KolibriOS and older Windows.

Shows the assembly a chosen compiler produces for C++, Rust, Go and many other languages.

Linux virtual machine that runs in the browser through WebAssembly.

Searchable list of emojis with meanings, used to label commit messages by intent.

Try ESLint and TypeScript-ESLint rules and inspect the AST in the browser.

Interactive Python console that runs CPython compiled to WebAssembly inside the page.

Turns a Git repository into one text digest of its code and structure for pasting into an LLM.

Matches each part of a shell command with the manual-page text that explains it.

Generates typed models in many languages from JSON, JSON Schema or GraphQL samples.

Public HTTP request and response service for testing clients, with endpoints for headers, status codes and delays.

Builds and tests JavaScript or PCRE regular expressions with live highlighting, contextual help and a searchable community library.

Reports the install and bundle size cost of an npm package.