Format Atlas

Container vs codec

A container packages media streams, while a codec encodes audio or video inside it. MP4 or MKV alone does not tell you whether a device supports the internal codec.

Formats

MP4MP4 is an MPEG-4 Part 14 container based on the ISO Base Media File Format. It can hold video and audio, but .mp4 alone does not identify codecs such as H.264, HEVC, AV1, or AAC.MOVMOV is based on the QuickTime File Format and can hold video and audio. The .mov extension alone does not reveal codecs, track layout, or compatibility with a recipient's tools.MKVMKV is a Matroska container, not a video codec. It can hold video, multiple audio and subtitle tracks, and chapters; playback depends on the internal formats and player.WebMWebM is a subset of Matroska for web media. It may combine VP8, VP9, or AV1 video with Vorbis or Opus audio; WebM itself is not a single codec or a guarantee of smaller files.AACAAC is a lossy audio codec standardized by MPEG. It may appear as a .aac file or an audio track inside a container; the codec is not the container.

Compare

MP4 vs WebMMP4 and WebM are containers for audio and video, not single codecs. MP4 is widely used across devices and services; WebM is a Matroska-based subset associated with web delivery. Size and quality depend on the encoded streams, settings, and playback environment.MOV vs MP4MOV and MP4 are container formats, not video codecs. MOV is common in QuickTime-oriented capture and editing workflows, while MP4 is widely used for general distribution. Playback depends on the actual video and audio codecs inside the file.MKV vs MP4MKV and MP4 are containers that can hold video, audio, subtitles, and metadata. MKV often supports a flexible mix of tracks, while MP4 is widely used for delivery across devices and services. Compatibility depends on the codecs and track features inside the file.

Guides

Choose a video distribution formatChoose the container and the codecs inside it according to the playback destination and production workflow.Choose an audio distribution formatFor delivery, check the listener's playback environment as well as file size and whether the source must remain available.

Related formats and reading

File formatsA file format defines how data is represented and interpreted. Choose one by the recipient's software, editing needs, fidelity and long-term access, not by extension alone.MIME typesA MIME type identifies the kind of content, often as type/subtype such as image/jpeg. It helps browsers and services handle files, but should be checked against the actual content.

References and specifications