What it does
Drop in an image, pick a target format (JPEG, PNG, WebP, AVIF, etc.), optionally set a target size, and get the converted file back. Entirely in the browser — no upload to a server required.
The interesting part
Image conversion usually requires a server with ImageMagick or Sharp. This app sidesteps that entirely by running FFmpeg compiled to WebAssembly in the browser.
FFmpeg is a massive C library. Compiling it to WASM and running it client-side isn't trivial — the binary is large and needs to initialise before any processing can happen. The UX challenge is making that initialisation feel acceptable rather than like the page is broken.
The payoff: zero server costs, zero privacy concerns (your images never leave your machine), and it works offline once loaded.
Tech
- Vue — frontend framework
- FFmpeg.wasm — FFmpeg compiled to WebAssembly, running entirely client-side
Source is private. Free to use at conv.mhelbich.de.