What is a MP4 file?
MP4 is a container rather than a codec: it usually holds H.264 video with AAC audio, which is the single most widely playable combination on the internet. It supports subtitles, chapters and multiple audio tracks, and streams well because metadata can sit at the front of the file.
At a glance
- Full name
- MPEG-4 Part 14
- Extensions
- .mp4, .m4v
- Type
- Video
- Introduced
- 2001
- Created by
- ISO/IEC (MPEG), ISO/IEC 14496-14
- Compression
- Lossy
- MIME type
- video/mp4
Strengths
- Plays on effectively every device, browser and editor
- Efficient compression with H.264 or H.265
- Supports subtitles, chapters and multiple audio tracks
Limitations
- H.264 and H.265 carry patent licensing obligations in some contexts
- Larger than an equivalent AV1 or VP9 encode
When to use MP4
Any video that must simply play, anywhere, without the recipient thinking about it.
You need a fully royalty-free pipeline. Use WebM.
Convert MP4 files
Every tool below runs in your browser unless it is labelled otherwise, so the file stays on your device.
MP4 to WebM
Converts MP4 video files into the WebM format that's widely supported across modern browsers and video-hosting platforms.
GIF to MP4
Converts an animated GIF into a compact, widely playable MP4 video file, cutting the overall file size down quite significantly.
MP4 conversions
Each page states what the target format cannot carry before you run it.
MP4 compared
Related video formats
Last updated 2026-08-03