A file extension does not always tell you which codec is required. MKV, MP4, MOV, WebM and AVI are containers that can hold different video and audio streams. If a file will not play, identifying the codec inside it is usually more useful than searching for a codec based only on the extension.
Use this page to understand the file you have. If Windows is missing playback support, the next step is to choose the Media Player Codec Pack edition that best matches your system.
1. Identify the formatCheck whether the extension is a container, codec stream or audio format, and what it normally contains.
2. Check what is insideContainers such as MKV, MP4 and MOV can hold different codecs. Use the File Inspector when the extension alone is not enough.
3. Add playback supportStandard suits most PCs, Plus adds advanced tools, and Lite keeps the installation smaller.
Modern and high-interest video formats
These formats and codecs account for many current playback questions, particularly around 4K, HDR, streaming, phones, cameras and downloaded video.
Established and legacy video formats
Older formats remain important because large personal, educational and downloaded-media archives still use them. Some now have relatively little modern documentation, even though users continue to encounter the files.
Audio formats
Audio files may be standalone or may appear as tracks inside video containers such as MKV, MP4, MOV, M2TS and AVI.
Codec families you may find inside these files
Containers describe how media is packaged; codecs describe how the audio or video is encoded. The same extension can therefore require different playback components from one file to another.
Modern video codecs
- AV1
- HEVC / H.265
- H.264 / AVC
- VP9
- VP8
Established and legacy video codecs
- MPEG-2
- MPEG-1
- MPEG-4 Part 2
- DivX
- Xvid
- VC-1
- Theora
- MJPEG
- DV
Common audio codecs
- AAC
- AC3 / Dolby Digital
- DTS
- FLAC
- ALAC
- Opus
- Vorbis
- MP3
- WMA
- PCM
This page is a practical guide rather than a guarantee that every codec profile, damaged file, DRM-protected stream or unusual container combination will play in every Windows application.
If the file is valid but Windows or your media player does not have the required decoder, choose an edition first and then continue to the official download page.
StandardRecommended for most Windows desktops and laptops with mixed modern and legacy media.
PlusFor advanced users, HTPCs and setups that benefit from the fullest toolkit.
LiteFor older or lower-power systems where a smaller package is preferred.