Everything in the catalog

Interactive chess lessons teaching piece movement, captures, and checkmate by playing mini games.

Shared analysis boards where you annotate games with comments and variations, alone or with others.

Flash Player emulator demo that plays SWF files you load, preserving old browser games and animations.

Turns any public GitHub repository into an interactive architecture diagram.

Over 100 PDF tools that run locally in the browser, with no uploads or sign-up.

Reduce PDF file size locally in the browser.

Annotate, highlight and redact PDFs in the browser.

Combine several PDFs into one file locally in your browser.

Make scanned PDFs searchable using in-browser OCR.

Extract pages or ranges from a PDF locally in your browser.

Run a real Postgres compiled to WebAssembly in the browser and try SQL against it.

Converts images, audio, video and documents locally in the browser using WebAssembly.

Linux virtual machine that runs in the browser through WebAssembly.

Open-source machine translation web UI and API; the hosted API needs a key but the page translates text.

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

Demo of a Notion-style editor that offers AI autocompletion as you write.

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.

HTML5 internet speed test that measures download, upload, ping and jitter.