What is H.264 (AVC)?
Definition
H.264, also called AVC or MPEG-4 Part 10, is the most widely supported video codec in the world. It plays on virtually every device, browser and editor, balancing good quality with near-universal compatibility, and is usually paired with AAC audio inside an MP4 file.
H.264 compresses video by predicting frames from earlier and later ones and storing only the differences, which keeps file sizes small while preserving good visual quality. Because it has been the default codec for around two decades, hardware decoders are built into phones, TVs, GPUs and game consoles, so playback is fast and battery-friendly. This near-universal support is the main reason it remains the safe default.
Most online video you watch is H.264 in an MP4 container with AAC audio. Newer codecs such as H.265 (HEVC), VP9 and AV1 are more efficient, producing smaller files at the same quality, but they are not supported everywhere and are slower to encode. H.264 trades some efficiency for the broadest possible reach.
A common confusion is mixing up the codec with the container: H.264 is the codec that encodes the picture, while MP4, MKV and MOV are containers that hold video and audio together. Another is assuming AVC and H.264 are different things, when they are simply two names for the same standard.
Quick facts
- Also known as AVC and MPEG-4 Part 10
- The most widely supported video codec across devices and browsers
- Usually stored in an MP4 container with AAC audio
- Less efficient than H.265, VP9 and AV1 (larger files at equal quality)
- The safest choice for sharing and broad compatibility