XviD (XviD MPEG-4 Video)
The open-source rebel codec that made high-quality video fit on a CD.
| Full name | XviD MPEG-4 Video |
| Extension | .xvid |
| MIME type | video/x-xvid |
| Developer | Xvid community (founded by Michael Militzer) |
| Released | 2001 |
| Type | Video codec (MPEG-4 Part 2 ASP) |
| License | GNU General Public License v2 |
| Common containers | AVI, MP4, MKV |
What is a XviD file?
XviD is a free, open-source video codec that compresses video using the MPEG-4 Part 2 Advanced Simple Profile standard. It became widely popular in the early 2000s for producing high-quality video at small file sizes. Files encoded with XviD are typically stored inside AVI or MP4 containers.
XviD is a codec, not a container format. The codec handles how video data is compressed and decompressed, while a container like AVI or MP4 wraps that compressed video together with audio and metadata. XviD follows the MPEG-4 Part 2 ASP specification, using techniques like B-frames, quarter-pixel motion compensation, and trellis quantization to achieve efficient compression. The name is a deliberate reversal of DivX, the proprietary codec XviD was created to challenge.
History
XviD grew out of the OpenDivX project, which DivXNetworks launched in January 2001 under Project Mayo. When DivXNetworks closed the project and released a proprietary DivX 4 codec built on the community's work, a group of developers forked the last open version of the encoding core. Michael Militzer, a German student, formally founded the XviD project in August 2001, releasing it under the GPL. Throughout the mid-2000s it became the dominant codec for sharing full-length movies over the internet.
Container vs codec
XviD-encoded video is stored as a stream of compressed frames inside a container file, most commonly AVI. The codec breaks each frame into 16x16 pixel macroblocks. I-frames (keyframes) are compressed independently using a technique similar to JPEG, capturing spatial detail within a single frame. P-frames and B-frames store only the differences from surrounding frames using motion estimation, which is what allows XviD to achieve high compression ratios without dropping to very low quality.
What it is used for
- Archiving DVD-quality movies at small file sizes for offline storage
- Playing back older video files downloaded or shared in the early-to-mid 2000s
- Converting XviD-encoded AVI files to modern formats like MP4 or MKV
- Low-bandwidth video distribution where H.264 encoders are not available
How to open it
VLC Media Player opens XviD files on all major platforms without any extra codec packs. Media players that rely on the system codec library, such as Windows Media Player, may need the Xvid codec package installed separately.
Pros and cons
Strengths
- Free and open-source with no licensing fees
- Good video quality at low bitrates for its era
- Widely supported by legacy media players and hardware DVD players
- Smaller file sizes than uncompressed or early MPEG-2 video
Trade-offs
- Superseded by H.264 and H.265, which offer better quality at the same file size
- No native support in modern web browsers
- Typically requires a separate audio track inside a container; the .xvid extension alone is rarely used in practice
- Limited to standard definition and early high-definition resolutions in common use
Convert XviD files
Free, in your browser, no signup. Start at the XviD converter, or jump straight to a popular conversion below.
Curious how fast and how small? See our measured conversion benchmarks.
XviD FAQ
Is XviD the same as DivX?
No. Both encode video using MPEG-4 Part 2, but DivX is a proprietary commercial codec and XviD is open-source. XviD was created as a free alternative after DivXNetworks closed the OpenDivX project.
Can I play an XviD file without installing anything?
VLC Media Player plays XviD files out of the box on Windows, macOS, and Linux. Most other players will need the Xvid codec package installed.
Why do most XviD files have an .avi extension instead of .xvid?
XviD is a codec, not a container. The video stream is packaged inside a container format, and AVI was the most common choice. The .xvid extension is rare; the codec inside an AVI file is what identifies it as XviD-encoded.
Should I convert my XviD files to MP4?
Yes, if you want broad compatibility. Modern devices, browsers, and streaming services expect H.264 or H.265 inside an MP4 or MKV container. Converting an XviD AVI to MP4 will make it playable almost everywhere.