Video formats AIX Player plays on Windows

AIX Player registers 81 video file types with Windows and decodes the video, sound and subtitles inside them in the app. You do not install a codec pack, and nothing is added to the rest of your PC. This page lists the file types and codecs, and links to a guide for each common format.

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Windows 11 & 10 · Updated 28 October 2026

Container or codec: the difference that matters

A file extension such as .mkv, .mp4 or .avi names the container: the box. Inside are tracks compressed with a codec: HEVC, AV1 or H.264 for the picture, AAC or Dolby Digital for the sound. Two MP4 files can hold different codecs, which is why one plays and the other does not. A player needs a decoder for every track inside, not just for the extension, and AIX Player carries those decoders itself.

The file types it opens

• Everyday video: MKV and MK3D, MP4 and M4V, MOV and QT, AVI, WMV and WM, WebM.
• Discs and broadcast: TS, M2TS and MTS, VOB, VRO, EVO, MPEG, MPG, M1V and M2V, MXF, DVR-MS and WTV recordings.
• Older and web formats: FLV and F4V, 3GP and 3G2, ASF, RM and RMVB, DivX and XVID files, OGM and OGV, AMV, DV, NUT and NUV.

That is a selection; the full list has 81 extensions. Two things are deliberately not on it: playlist files (.asx and .wpl), and Blu-ray .bdmv index files. Blu-ray video itself plays from its .m2ts stream files.

Video codecs decoded in the app

HEVC (H.265), AV1, H.264, VP9 and VP8, MPEG-1 and MPEG-2, VC-1 and WMV 1, 2 and 3, MPEG-4 Part 2 (DivX and Xvid), H.263, RealVideo, ProRes, DNxHD, Theora, Cinepak, Sorenson Video 3 and Flash video. Hardware decode is on by default: where your graphics chip supports a codec it does the work, and the processor takes over where it does not.

Sound

AAC, MP3, Dolby Digital (AC-3) and E-AC-3, DTS including DTS-HD MA, TrueHD, FLAC, ALAC, Opus, Vorbis, WMA and Cook all decode in the app. Surround speakers get every channel; stereo speakers and headphones get a downmix. If a video plays silently, the no-sound guide finds the cause.

Subtitles

Subtitle files saved beside the video: SRT, ASS and SSA, VTT, SUB/IDX, SUP, SMI, AQT, JSS, RT, SCC, TTXT, UTF and MKS. Inside the video: text tracks, and picture-based tracks from discs (PGS from Blu-ray, VobSub from DVD, and DVB), plus closed captions. Teletext subtitles are not supported. Text subtitle files are read as UTF-8, or UTF-16 with a byte-order mark.

Resolution, bit depth and HDR

There is no resolution cap below 8K, so video up to 8K plays wherever your PC can decode it. 4K and 10-bit video in standard range (SDR) is free without a time limit. HDR video, meaning HDR10, HDR10+, HLG and Dolby Vision, is part of AIX Pro and has a separate free allowance: see Free and Pro. On an ordinary screen AIX Player tone-maps HDR to fit.

Format guides