Convert MKV to AVI — Free & Private

Will my video be re-encoded or just remuxed when converting MKV to AVI?

Almost always re-encoded. MKV files typically carry modern codecs — H.264, H.265, VP9, or AV1 — that the much older AVI container was never designed to hold reliably. To produce a working AVI file, Convertlo re-encodes the video into an AVI-compatible codec and converts the audio track to match, so the result is a genuine transcode rather than a copy.

• H.264/H.265-in-MKV → AVI: re-encoded, since AVI predates these codecs
• VP9/AV1-in-MKV → AVI: re-encoded, no AVI player supports these natively
• Rare older MKV files already holding DivX/Xvid can sometimes remux instead
• Re-encoding takes longer than a remux but ensures the AVI actually plays

Will MKV's multi-track audio or embedded subtitles survive in AVI?

No. AVI does not support embedded subtitles — all subtitle tracks are dropped silently during conversion. AVI also has limited multi-audio support, so only the primary audio track carries over. If your MKV has multiple language tracks or subtitles you want to keep, extract the subtitle as a separate .srt file using MKVToolNix before converting; you can re-add it in your video editor afterward. VLC opens AVI files on any platform, and Windows Media Player and older Windows video editors handle AVI natively.

• VLC, Windows Media Player, legacy editing software: full support
• iPhone, Android, and web browsers: no native AVI playback
• Social platforms (YouTube, Instagram, TikTok) don't accept AVI uploads directly
• If the file needs to work on phones or online, MP4 is the better target

How much will the file size change going from MKV to AVI?

The file often grows. AVI's compatible codecs (DivX/Xvid-style or constrained encoders) are less efficient than the H.264, H.265, VP9, or AV1 typically found inside MKV, so achieving similar visual quality in AVI usually needs a higher bitrate — and a larger file.

• H.265/AV1-in-MKV → AVI: often a noticeable size increase for equivalent quality
• H.264-in-MKV → AVI: usually larger, though less dramatically
• Lowering the target quality can offset some of the increase
• If file size matters, keeping the file in MKV or converting to MP4 is more efficient

Why is converting MKV to AVI not recommended in most cases?

AVI is technically inferior to MKV in almost every way: it has file size limits, no embedded subtitle support, limited audio track support, and doesn't handle modern codecs (H.265, AV1) well. Converting MKV to MP4 is a better choice in nearly all modern situations — MP4 is just as widely compatible as AVI while supporting modern codecs and being universally accepted by phones, smart TVs, and social platforms. AVI is mainly useful when a specific older program — legacy video editing software, an embedded device, or a tool that only accepts AVI input — requires that exact container. Outside of those cases, MP4 is smaller, plays everywhere, and is the better default.

• Use AVI only when older software or hardware specifically requires it
• MP4 is the universal choice for phones, browsers, and social platforms
• Keep the original MKV as your archive copy if you need flexibility later