MP4, WebM, MKV: Which Video Format to Choose When Downloading

When you download a video, you face a choice: MP4, WebM, or MKV? Each format has its advantages and limitations. In this guide we compare the most common formats so you can pick the one that best fits your needs.

MP4: the universal standard

MP4 (MPEG-4 Part 14) is the most widely used video format in the world. It is the one you should choose by default unless you have a specific need.

• Compatibility: works on virtually every device, browser, smart TV, and media player.
• Quality: excellent quality-to-size ratio with the H.264 or H.265 codec.
• Size: relatively compact files.
• Best for: general use, sharing on WhatsApp, uploading to social media.

WebM: Google's format

WebM is an open format developed by Google. It is YouTube's native format for high-quality videos.

• Compatibility: excellent in browsers (Chrome, Firefox, Edge); limited on older devices.
• Quality: better than MP4 at the same file size with the VP9 or AV1 codec.
• Size: generally more compact than MP4 at the same quality.
• Best for: videos to watch in the browser, storing many videos while saving space.

MKV: the all-in-one container

MKV (Matroska) is less a format and more a container that can hold multiple video, audio, and subtitle tracks in a single file.

• Compatibility: requires players like VLC; does not work natively on many devices.
• Quality: the best possible, since it supports any codec without re-encoding.
• Size: variable, depending on the codec used.
• Best for: archiving videos with multiple audio/subtitle tracks, movies.

AVI: the legacy format

AVI was the standard in the 2000s but is now obsolete. Large files, no modern support for embedded subtitles, and inferior compression. We do not recommend it for new downloads.

Comparison table

• MP4 — Compatibility: Universal | Quality/Size: Very good | Recommendation: General use
• WebM — Compatibility: Browsers | Quality/Size: Excellent | Recommendation: Space saving
• MKV — Compatibility: VLC/PC | Quality/Size: Best | Recommendation: Archiving
• AVI — Compatibility: Legacy | Quality/Size: Poor | Recommendation: Not recommended

What format does PullVid use?

When you download a video with PullVid, we show you all available options with the format and resolution for each one. In most cases we recommend MP4 for maximum compatibility, or WebM if you prefer better quality at a smaller file size.

Resolution vs format: which matters more?

Resolution (1080p, 4K) determines the sharpness of the video. Format determines compression and compatibility. A 1080p video in MP4 will look great on any screen. A 4K video in WebM will look stunning but requires a compatible device.

For most users, 1080p in MP4 is the perfect combination. If you have a 4K screen and plenty of storage, check out our guide on how to download videos in 4K. For all methods and platforms, the ultimate guide to downloading videos covers every aspect.