Video
Video Formats Explained: MP4 vs MOV vs MKV vs WebM
Video files come in a confusing array of formats. Understanding the difference between a container and a codec makes it obvious which one you should use for editing, sharing, or the web.
Containers vs codecs
A video file has two parts: a container (like MP4, MOV, or MKV) that holds everything together, and codecs (like H.264 or AV1) that compress the actual video and audio inside. The container is the box; the codec is how the contents are packed. This is why two MP4 files can behave differently - it depends on the codecs inside.
MP4: the universal choice
MP4 is the format you should reach for when in doubt. It usually pairs H.264 video with AAC audio and plays on virtually every device, browser, and platform. It is the required or recommended upload format for YouTube, most social networks, and messaging apps. If you need one format that just works, it is MP4.
MOV: Apple's editing format
MOV is Apple's QuickTime container, used by iPhones and Mac editing tools like iMovie and Final Cut. Quality is excellent and it is ideal inside the Apple ecosystem, but it is less universally accepted elsewhere, so converting MOV to MP4 is common before uploading or sharing widely.
MKV: the archivist's container
MKV (Matroska) is a flexible open container that can hold multiple video, audio, and subtitle tracks plus chapters in one file. That makes it popular for high-quality film archives and multi-language collections. The trade-off is limited native support on phones and browsers, so MKV to MP4 is often needed for playback and sharing.
WebM: built for the web
WebM is an open, royalty-free format designed for HTML5 video. It produces small files at good quality and plays natively in browsers, making it great for embedded and background video. Outside the browser its support is thinner, so it is not the best choice for offline sharing.
Which should you convert to?
Match the format to the destination:
- Uploading or sharing anywhere: convert to MP4.
- Editing on a Mac or iPhone: MOV works natively.
- Embedding video on your own website: WebM (with an MP4 fallback).
- Archiving with multiple tracks: MKV, then export MP4 copies to share.