DivX to MKV Converter

How to Convert DivX to MKV Online

1. Upload Your DivX File: Drag and drop or click "Add Files" to select your .divx clip. Batch is supported — queue several rips and download them individually or as a ZIP.
2. Pick File Compression and Codec: Default is Quality Preset on "Very High (Recommended)" with H.264 video and AAC audio — the safest pair for Plex direct play, smart TVs, and mobile clients. Switch to Constant Quality and set CRF (0–51, default 23 for H.264), Constant Bitrate (default 4 Mbps), Variable Bitrate (target 4, min 2, max 8 Mbps), or Specific file size. MKV also accepts H.265, AV1, VP9, the original DivX/Xvid stream (passthrough, no re-encode), plus AC3, DTS, E-AC3, FLAC, Opus, and Vorbis audio.
3. Adjust Video resolution and Trim (Optional): Keep original, pick a Preset Resolution (144p–4320p), scale by Resolution Percentage, or enter Width × Height. Use Trim → Time Range to clip a start and duration in HH:MM:SS.sss.
4. Convert and Download: Click Convert. Files process in your browser session — no sign-up, no watermark, no upload to a third-party server.

Why Convert DivX to MKV?

DivX is the MPEG-4 Part 2 codec popularised in the early-2000s DVD-rip era — originally a 2000 reverse-engineering of Microsoft's MPEG-4 v3 codec by Jérôme Rota, then rebuilt as a commercial product from DivX 4 onward. MKV (Matroska) is the modern open container, announced December 2002 by Steve Lhomme as a fork of the Multimedia Container Format and standardised as IETF RFC 9559 in October 2024. Converting from DivX-in-AVI to MKV gets you a future-proof wrapper without necessarily re-encoding.

• Pack multiple audio tracks and subtitles in one file — MKV holds an unlimited number of video, audio, picture, and subtitle tracks. AVI/DivX cannot. This is the single biggest reason to switch when you have a director's-commentary track, a foreign-language dub, or burned-out SRT/ASS subtitles to embed.
• Plex, Jellyfin, and Kodi libraries — Plex's direct-play target is MP4/H.264/AAC, but H.264-in-MKV typically remuxes (Direct Stream) with very low CPU rather than full transcode. Re-encoding old DivX to H.264 inside MKV cuts transcode load on Plex servers and Roku/Apple TV/Chromecast clients.
• Modernise old DVD rips — DivX Home Theater profile maxes at 1080p/30 with restrictive bitrate caps. Re-encoding to H.264 at CRF 20–23 typically halves file size at equal perceptual quality and lifts those caps.
• Chapters, attachments, and metadata — MKV supports chapter markers, embedded fonts (critical for ASS karaoke subtitles), cover art, and arbitrary file attachments. Useful for archived TV-show rips and anime.
• Codec passthrough when you only need a new container — Pick the DivX or Xvid codec to keep the original MPEG-4 Part 2 stream byte-for-byte, gaining MKV's multi-track and chapter features without quality loss from re-encoding.
• Better error recovery on large files — Matroska's EBML structure lets players seek and resync after a corrupted block; AVI's flat index can fail outright if the tail of the file is truncated.

DivX vs MKV — Format Comparison

Encode Settings Quick Guide

CRF is logarithmic: a 6-point drop roughly doubles the bitrate. CRF 18 is widely cited as visually lossless for H.264; CRF 28 for H.265 is roughly the H.264-CRF-23 equivalent at half the file size.

Frequently Asked Questions

Will converting DivX to MKV improve quality?

No — converting between formats can never add detail that wasn't in the source DivX file. What it can do is preserve the existing quality more efficiently (H.264 or H.265 at a sensible CRF will look the same as the DivX original at roughly half the size) or stop a player from struggling with the legacy codec. If you only want the MKV wrapper benefits, choose DivX or Xvid as the output codec to copy the stream without re-encoding.

Should I keep the original DivX stream or re-encode to H.264?

Re-encode to H.264 if you want smaller files, better Plex compatibility, or finer trim points. Keep DivX/Xvid passthrough if you want a near-instant conversion, perfect quality preservation, and only need MKV's multi-track or chapter features. AVI's index is brittle on large files; even a pure remux to MKV is worthwhile for long-term storage.

Will Plex direct-play an MKV with H.264 and AAC?

Plex's documented direct-play target is MP4 with H.264 (level 4.0 or lower), AAC stereo, and 1920×1080/30. MKV with the same codecs typically Direct Streams instead — Plex remuxes on the fly with very little CPU, far cheaper than full transcoding. If your client is a Roku or Apple TV that natively plays MKV (most current models do), you'll often still get true Direct Play. If you want guaranteed direct play across every client, convert to MP4 with DivX to MP4 or MKV to MP4 instead.

Can MKV hold multiple audio tracks and subtitles?

Yes — Matroska's defining feature is that one file can carry an unlimited number of video, audio, picture, and subtitle tracks. Plex, Jellyfin, Kodi, and VLC will detect them all and let you switch language, commentary, or subtitle track during playback. You'll need to add extra tracks with a tool like MKVToolNix after conversion; this converter outputs the source DivX video plus its embedded audio.

What's the difference between DivX, Xvid, and MPEG-4 Part 2?

All three implement the same MPEG-4 Part 2 video standard. DivX is the proprietary commercial codec from DivX, LLC. Xvid is an open-source GNU GPL fork of OpenDivX, started by ex-DivXNetworks contributors in 2001. Most "DivX" rips from the 2003-2010 era are actually Xvid; players treat the two as interchangeable. MKV will store either one losslessly via codec passthrough.

What audio codec should I pick?

AAC (default) for the broadest device support — every smart TV, phone, and streaming box plays it. AC3 or E-AC3 if your DivX source has 5.1 surround you want to preserve unaltered. FLAC for lossless archival. Opus for the smallest size at equal quality, but compatibility is narrower outside of Chrome, Firefox, VLC, and recent mpv builds.

Are MKV files larger than the source DivX?

Container overhead is negligible — the MKV header adds well under 1% versus AVI for typical movie-length files. If your output is larger, the cause is usually re-encoding at a CRF lower (sharper) than the DivX source quality, or a higher target bitrate. Drop CRF only one or two steps from the source-equivalent value, or use Compress MKV afterward to trim further.

Can I trim or cut sections during conversion?

Yes. Use Trim → Time Range to set a start time and duration in HH:MM:SS.sss. For multi-segment cuts (commercial removal across several break points), the dedicated Video Cutter handles multi-range editing. Trim during conversion always re-encodes around the cut points; passthrough is disabled for trimmed clips.

Does this work on mobile and without installing anything?

Yes — conversion runs in the browser session. There's no installer, no sign-up, no watermark, and no upload to a third-party cloud. Large multi-GB DivX files will be slow on a phone because the work happens on-device; for files over a few hundred MB, a desktop browser is faster.