September 2026
When you download a video with Avidder, you'll usually see a quality dropdown but not much said about the file format itself. Here's what's actually happening behind the scenes, and why it matters.
MP4 (technically MPEG-4 Part 14) is the most widely supported video container in the world. It plays natively on phones, smart TVs, game consoles, and every major browser and operating system without needing extra software. Avidder converts most video downloads into MP4 by default for exactly this reason — it's the format least likely to give you trouble later.
WebM is an open, royalty-free format built for the web. It often produces smaller files at a similar visual quality to MP4, and it's what YouTube itself frequently streams behind the scenes. The trade-off is compatibility — some older devices, video editors, and media players don't support WebM as smoothly as MP4, particularly on Windows and older smart TVs.
If you only need the sound — a podcast segment, a music track, a lecture — Avidder's "Audio only" option extracts just the audio stream and saves it as an MP3. This produces a much smaller file than keeping the video, and MP3 is playable on essentially every device made in the last two decades.
For most people, most of the time, the default MP4 option is the right call — it just works, everywhere.