MP4 is the default video container for the modern internet — a universally compatible package that holds video, audio, and subtitles, and plays on every browser, phone, and operating system.
Safe format
Type Video
By ISO / MPEG
MIMEvideo/mp4
Drop any file to identify it
We read file headers, not extensions. Nothing gets uploaded.
MP4 is the default video container for the modern internet — a universally compatible package that holds video, audio, and subtitles, and plays on every browser, phone, and operating system. If you've watched a video online in the last decade, you've watched an MP4. It's the format behind YouTube, TikTok, Netflix streams, Zoom recordings, and the video your cousin posted of their cat. MP4 isn't actually a video format — it's a container. Think of it as a box that holds a video track (usually compressed with H.264 or H.265), an audio track (usually AAC), and optionally subtitles and metadata. The container itself doesn't determine quality; the codec inside does. When in doubt about what video format to use, the answer is MP4.
Technical details
Full Name
MPEG-4 Part 14
MIME Type
video/mp4
Developer
ISO / MPEG
Magic Bytes
00 00 00 ?? 66 74 79 70
Safety
.mp4 is a known, safe format.
What opens it
VLC
FREEAll
Every web browser
FREEAll
Windows Media Player
FREEWindows
Apple QuickTime
FREEmacOS
Convert with fwip
Convert .mp4 files instantly in your browser. No upload, no signup, no subscription. Your files never leave your device.
Free in your browser. Batch processing & offline mode in the desktop bundle.
FAQ
What's the difference between MP4 and MOV?
Both are video containers and can hold the same codecs. MOV is Apple's format and works best in Apple's ecosystem. MP4 is the universal standard — if you need a video to play everywhere, use MP4. You can convert MOV to MP4 with <a href="https://fwip.app/tools/mov-to-mp4/">fwip</a> without re-encoding.
How do I compress an MP4 video?
Use <a href="https://fwip.app/tools/compress-video/">fwip's video compressor</a> to reduce file size in your browser. It re-encodes the video at a lower bitrate. No upload, no account required.
What's the difference between MP4 and MKV?
MKV supports more features — multiple audio tracks, chapter markers, more codecs — but MP4 plays on far more devices. MKV is the enthusiast's choice for archiving; MP4 is the safe choice for sharing.