When is AVI still useful?
AVI remains useful for legacy Windows applications, older playback hardware, and specialized systems that reject modern MP4 files. For current browsers and phones, keeping the MP4 is usually the better choice because it is smaller and more widely supported.
Why can an AVI output be larger?
This tool uses MPEG-4 Part 2 video and MP3 audio for practical AVI compatibility. Those codecs are less efficient than the H.264 and AAC combination common in MP4, so the output can be larger even when the visible quality is similar.
- Output container
- AVI
- Video / audio
- MPEG-4 Part 2 / MP3
- Best for
- Legacy Windows workflows
How to convert MP4 to AVI
- 1
Choose one MP4 video up to 100 MB.
- 2
Select an output quality and start the local browser conversion.
- 3
Preview and download the converted .avi file.
Frequently asked questions
Will the AVI play in every old device?
No single AVI codec works everywhere. This tool uses a common MPEG-4 and MP3 combination, but very old devices may require a device-specific resolution or codec.
Is this MP4 to AVI converter private?
Yes. The video is processed by WebAssembly inside your browser and is not uploaded to Free2Convert. Closing or refreshing the tab removes the working data.
Why can browser video conversion take several minutes?
Video decoding and encoding require substantial CPU and memory. Speed depends on the video duration, resolution, source codec, quality setting, and your device.