Or more likely, ffmpeg binary is embedded, considering that they don't provide instructions to download it on that page.

Yes, ffmpeg is included. It takes up 2.4MB. The rest is electron bloat.

That's not big enough to include even most native components. My essentials build with only common 3rd party libs (like libx264) compresses to 20MB with LZMA2.

I just looked inside the linux appimage. There's only a 2.4MB libffmpeg.so and it doesn't link against anything else than libc stuff.

You are all on point! Great analysis. - Yes, it's electron (didn't expect such a huge build for such a small app). - The bundled ffmpeg is probably a light version that comes from the underlying chrome. - The app detects if there's a ffmpeg available otherwise it downloads the binaries and uses them instead.