MP4 file format
MPEG-4 Part 14
MP4 is the world's most compatible video format. It usually holds H.264 video with AAC audio and plays on virtually every phone, browser, TV and editing app.
| Property | MP4 |
|---|---|
| File extensions | .mp4, .m4v |
| MIME type | video/mp4 |
| Introduced | 2001 by MPEG (ISO/IEC 14496-14) |
| Typical video codecs | H.264, H.265/HEVC, AV1 |
| Typical audio codecs | AAC, MP3 |
| Plays in web browsers | Yes — every browser |
| Compatibility | Universal: phones, TVs, editors, social media |
| Best for | Sharing, uploading, streaming, editing |
What is an MP4 file?
MP4 (MPEG-4 Part 14) is a container format standardised in 2001 and based on Apple's QuickTime file structure. A container holds separately compressed video and audio streams plus metadata such as subtitles, chapters and cover art. Most MP4s use H.264 video and AAC audio; newer files may use H.265 (HEVC) or AV1.
Because the format is an international standard, it's supported by every major browser, operating system, phone, smart TV and social network — which is why converting to MP4 is the safest choice when you're not sure what a recipient can play.
Strengths and weaknesses
MP4 is compact, streamable (the 'faststart' option lets playback begin before download finishes) and universal. It's less flexible than MKV — it can't hold every codec or subtitle format — and editing an MP4 repeatedly re-compresses the video each time.
When should you use MP4?
Use MP4 for almost everything you share or upload. Keep MKV for archives with multiple audio or subtitle tracks, and WebM when a web project specifically needs royalty-free codecs.