Convert MP4 to AVI Online
Convert modern MP4 videos to legacy AVI format for old players, car stereos, and DVD authoring. Free, in your browser, no file uploads.
.mp4 · up to 100 MB
What you can do
MP4 to AVI: compatibility with legacy players and systems
Car players
Convert MP4 to AVI for car multimedia systems that don't recognize H.264.
DVD authoring
AVI is the input format for most DVD creation software.
100% private
Conversion happens in your browser. Your video is never uploaded to any server.
Instant
No queues or waiting. Direct conversion in your browser.
How it works
Three steps, no hassle
Upload your MP4 video
Drag or select your .mp4 file. Up to 500 MB, no signup required.
Conversion to AVI
MP4 video and audio are remuxed or transcoded to the AVI container in your browser. Compatible with MPEG-4 and legacy codecs.
Download your AVI
Get an AVI file ready for DVD players, car multimedia systems, older Smart TVs, or authoring software.
FAQ
Got questions?
AVI is still necessary in several specific scenarios. First, car multimedia players: many infotainment systems manufactured before 2015 only read AVI from USB drives, with limited or no support for MP4 with H.264. Second, DVD recorders and authoring: DVD creation software like Nero Vision, DVDFlick, or TMPGEnc Authoring Works may require AVI as input before encoding to MPEG-2 for the final DVD. Third, low-end Smart TVs from Chinese manufacturers (very common in Latin American and African markets) that recognize AVI with MPEG-4 but not MP4 with H.264/H.265. Fourth, certain surveillance systems and DVRs that play AVI clips for historical recording review.
Video quality depends on the codec and bitrate, not the container (MP4 or AVI). AVI can contain virtually the same codecs as MP4: MPEG-4 Part 2 (DivX, Xvid), H.264, even H.265, as well as older codecs like MPEG-1, MPEG-2, or Indeo. Pure container conversion (remuxing), when the codec is compatible, involves no quality loss at all. If transcoding is required (codec change), quality depends on the target codec and chosen bitrate. Given equal codec and bitrate, MP4 and AVI produce identical quality.
AVI does not natively support the most efficient modern compression codecs like H.264 or H.265 in the same way as MP4. Historically, AVI files with MPEG-4 Part 2 codecs (Xvid, DivX) at the same resolution and visual bitrate as H.264 are 20–40% larger because MPEG-4 Part 2 is less efficient than H.264 (a later codec with better compression for the same quality). If AVI encapsulates H.264, the size is similar to MP4. Additionally, AVI does not standardly support modern audio formats like AAC or Opus; it uses MP3 or PCM, the latter being much heavier.
The main devices that still require AVI are: (1) Portable DVD players with USB ports or SD slots not updated to read H.264. (2) Car infotainment systems manufactured 2008–2015 by Toyota, Honda, Hyundai, Kia, and others with factory firmware. (3) Low-cost TVs manufactured in China and sold in emerging markets between 2012–2020. (4) Previous-generation gaming consoles like Xbox 360 and PlayStation 3 that support AVI/Xvid for local video playback. (5) Security monitoring systems (CCTV) with DVRs from the 2010–2016 generation.
AVI has very limited support for subtitles and multiple tracks compared to MP4 or MKV. The RIFF container was designed by Microsoft in 1992 for video with a single video track and up to two audio tracks (for stereo or dual-language audio). Embedded subtitles are not part of the original AVI standard; the OpenDML extension (Matrox, 1996) added support for files larger than 2 GB and some additional flexibility, but subtitle support still depends on the player software. In practice, subtitles in AVI are handled as external files (.srt, .sub) that the player loads separately.
AVI (Audio Video Interleave) was developed by Microsoft as part of Video for Windows and released with Windows 3.1 in November 1992. It is based on RIFF (Resource Interchange File Format), using a chunk structure identified by four-character codes (FourCC). In its early years, AVI was the dominant video format on PC, used for CD-ROM video clips, games, demoscene demos, and consumer digital video. With the rise of DivX in 2000–2002 (a pirated MPEG-4 Part 2 codec based on DVD video files) and its legal successor Xvid (released 2001), AVI became the standard format for sharing compressed movies over the internet during the data CD-ROM and peer-to-peer era (Napster, KaZaA, eMule). MP4 with H.264 gained ground from 2005 with the rise of YouTube and Apple's iPod devices, and by 2010 was the dominant format.
Convert MP4 to AVI: compatibility with legacy players and systems
AVI (Audio Video Interleave) is a multimedia container format developed by Microsoft and released on November 10, 1992 alongside the Video for Windows (VFW) subsystem in Windows 3.1. It is based on RIFF (Resource Interchange File Format), a data chunk architecture identified by four-character codes (FourCC) that Microsoft originally developed for Windows MIDI format (WAV and MIDI also use RIFF). The basic AVI structure consists of hdrl chunks (header describing video and audio properties), movi (interleaved video and audio data), and idx1 (position index for random access). This architecture, while functional, has important limitations: the original design did not accommodate files larger than 2 GB (partially resolved with the OpenDML extension by Matrox in 1996), does not support native seekable streaming (each frame is not self-contained as in MP4 with moov atoms), and metadata support is rudimentary compared to modern containers.
The reason AVI remains necessary in 2025 is the enormous installed base of devices with non-updatable firmware. Car infotainment systems manufactured between 2005 and 2015 by virtually all manufacturers (Toyota, Honda, Ford, Volkswagen, Hyundai, Kia, Renault) include USB or SD card players with factory firmware that recognizes AVI with MPEG-4 Part 2 (Xvid/DivX) as the video format. These systems do not receive firmware updates that add support for MP4/H.264, and vehicle owners do not replace the infotainment system for cost reasons. In the Latin American and Sub-Saharan African markets, where hardware turnover is slower, this installed base is particularly significant. Additionally, DVD authoring software (creating menus and DVD-Video structure) like DVDFlick, TMPGEnc Authoring Works, and DVD Architect typically accepts AVI as more reliable input than MP4 before the MPEG-2 transcoding stage for the DVD master.
From a technical perspective, converting MP4 to AVI can be a remuxing operation (if the MP4 video codec — H.264, MPEG-4 Part 2 — is compatible with AVI) or a full transcoding (if a codec change is required). Pure remuxing involves no quality loss: video and audio packets are extracted from the MP4 container and packaged into AVI without re-encoding. However, AVI has audio limitations: the standard format uses PCM (uncompressed) or MP3 audio, but not AAC natively (though some extended players support it). This means if the MP4 contains AAC audio (the most common case), the audio needs to be transcoded to MP3 or PCM to guarantee maximum compatibility in the resulting AVI. Convertir.ai handles this audio transcoding automatically in the browser using WebAssembly, producing an AVI compatible with the widest possible device base without requiring the video to be uploaded to any server.