I wanted to extract audio from videos directly on my phone, so ffmpeg on the command line wasn’t an option. Audio Extractor is the little webapp I made for that. The video below shows how it works.
The implementation began with ffmpeg.wasm, but I switched to Mediabunny for its dramatically smaller bundle. It seems to do the job just as well.
I “wrote” the entire app by directing an AI agent, without touching a line of code. It still amazes me how easy it is nowadays to create personalized tools!