Everything in the catalog

Write dated events in plain text and view them as a timeline, calendar or Gantt chart.

Typing practice that adapts lessons to your weakest keys as you type.

Block-based programming editor for making games, stories and animations, usable without logging in.

Shows what the compiler generates behind C++ features by expanding your code into explicit source.

Drag-and-drop section templates and a Markdown editor for assembling a project README.

Lints GitHub Actions workflow files in the browser using the WebAssembly build of actionlint.

Shows your public IP address with country, city and ASN details.

Playground for the Viz.js library that renders Graphviz DOT to SVG entirely with WebAssembly.

Converts ASCII art diagrams into clean SVG graphics.

Edit, simplify and convert geographic data such as Shapefile, GeoJSON and TopoJSON in the browser.

Turns a pasted GitHub repository URL into an interactive map of the code's architecture.

Opens 3D model files such as OBJ, STL, 3DS and glTF in the browser, with local processing noted on the page.

Stable Diffusion that runs completely in the browser through WebGPU, with no server-side inference.

Ambient sound mixer with rain, forest, cafe and noise loops for blocking distractions and relaxing.

HTML5 speed test for measuring download and upload speeds, also usable on a local network.

Image editor with layers, filters and basic drawing tools that runs as a static web page.

Converts a docker run command into docker-compose YAML.

Practise hiragana, katakana, kanji and vocabulary through short games with many themes.

Visual editor for commutative diagrams that exports LaTeX code for tikz-cd.

Renders PostgreSQL EXPLAIN output as an annotated tree so slow plan nodes stand out.

Draw digital timing diagrams and bit-field layouts from a JSON-style description.

Generates realistic fake JSON that conforms to a JSON Schema.

Renders a unified git diff as side-by-side or line-by-line HTML with syntax highlighting.

Type indented text and get a flowchart or mind map drawn automatically beside it.