⚡EVERYTHING CONVERTER

This tool was inspired by "I Made the Ultimate File Converter" by PortalRunner. The video walks through building a browser-based converter that can chain formats through a graph of tools — including some wonderfully absurd ones like Portal 2 replay files. If you haven't seen it, it's a great watch.

This tool borrows the core idea — a conversion graph that finds paths between formats — but is far simpler in scope. PortalRunner's version pulls in FFmpeg and ImageMagick via WebAssembly, handles audio-to-image via Fourier transforms, and even includes a custom Office document parser. This one sticks to what vanilla JS and a handful of CDN libraries can do in a single HTML file — grown over many sessions of collaboration between Claude and a human with a taste for absurd conversion chains. What started as a quick experiment now spans over a hundred converters, several from-scratch codecs (QR, GIF, MIDI, STL…), and a manual chain builder.

Different constraints, different results. If you want the full experience, check out PortalRunner's project. If you just need a quick, private conversion without leaving your browser tab — this might be enough.

Every supported format is a point on a graph. When you pick a target format, the converter finds the shortest path between your file's format and the target — even if that means going through intermediate steps automatically.

For example, converting an Excel file to YAML goes through JSON as an intermediate step. You don't need to worry about this — it all happens automatically in the background.

External libraries (like SheetJS for spreadsheets) are only loaded when actually needed, so the page stays fast.

Your files never leave your device. All conversions happen locally using JavaScript in your browser. No data is sent to any server. You can even use this tool offline once the page is loaded.