Video File Formats — WhatThisFile

About video files

Video files are the most misunderstood format category on the internet. People say "MP4" when they mean H.264. They say "codec" when they mean "container." A video file is a box (the container) holding separate streams (video codec, audio codec, subtitles) — and which box you use determines what can play it.

MP4 won the container wars for consumers. MKV won for archivists and enthusiasts. MOV is what your iPhone records. AVI and WMV are leftovers from a previous era that refuse to fully disappear. The codec inside matters more than the container — H.264 plays everywhere, H.265 is better but less compatible, and AV1 is the open-source future that takes forever to encode.

The single most common video problem is "my device won't play this file." The solution is almost always the same: convert to MP4 with H.264 video and AAC audio. That combination plays on every browser, phone, TV, and operating system. It's not the most efficient encoding, but compatibility is king.

All video formats

.3gp 3GP is a video format for older mobile phones — heavily comp... .ass ASS is a styled subtitle format supporting fonts, colours, p... .avi AVI is a legacy video container from Microsoft — one of the ... .divx DivX is a legacy video codec and container from the early 20... .f4v F4V is Adobe's later Flash video format, essentially an MP4 ... .flv FLV is Adobe Flash's video format — once behind every web vi... .m2ts M2TS is the video container format used on Blu-ray discs and... .m4v M4V is Apple's video container — essentially an MP4 with opt... .mkv MKV is an open-source video container that supports virtuall... .mov MOV is Apple's native video container — the default recordin... .mp4 MP4 is the default video container for the modern internet —... .mpeg MPEG is the full-extension spelling of MPG — the same MPEG-1... .mpg MPG is a legacy video format using MPEG-1 or MPEG-2 compress... .mts MTS is the AVCHD camcorder format developed by Sony and Pana... .mxf MXF is a professional broadcast and post-production video co... .ogv OGV is an open-source video container from the Xiph.org Foun... .srt SRT is the most widely used text subtitle format — plain tim... .ts TS is a video transport stream format — designed for broadca... .vob VOB is the raw video/audio container format used on DVD-Vide... .vtt VTT (WebVTT) is the W3C standard caption format for HTML5 vi... .webm WebM is Google's open video format — VP8/VP9 or AV1 video wi... .wmv WMV is Microsoft's legacy video format — once bundled with e...

Format comparison

Format	Type	Compatibility	Features	Best for
.mp4	Container	Universal	H.264/H.265, AAC, subtitles	Everything (default choice)
.mkv	Container	Players only	Any codec, chapters, multi-audio	Archiving, media servers
.mov	Container	Apple + VLC	ProRes, H.264/H.265	iPhone video, pro editing
.webm	Container	Browsers	VP9/AV1, Opus	Web streaming
.avi	Container	Legacy	Limited metadata	Old archives
.wmv	Container	Windows only	WMV codec	Legacy Windows video

FAQ

What's the difference between a codec and a container?

A container (MP4, MKV, AVI) is the file format — the box. A codec (H.264, H.265, VP9) is the compression algorithm used on the video and audio inside. The same codec can live in different containers, and the same container can hold different codecs.

What's the most compatible video format?

MP4 with H.264 video and AAC audio. Every browser, phone, smart TV, and operating system plays it. When in doubt, this is the format to export or convert to.

Why can't my TV play this video file?

Smart TVs typically only support MP4 with H.264. If your file is MKV, uses H.265/HEVC, or has an unusual audio codec, the TV may refuse it. Convert to MP4 (H.264 + AAC) for maximum compatibility.

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