AVI to MP4 converter
FileReshape's AVI to MP4 converter turns AVI videos with DivX, Xvid, Motion JPEG, DV or H.264 picture into an MP4 with H.264 picture and AAC or MP3 sound, using FFmpeg in your browser. The video is not uploaded. H.264 is copied in seconds; older codecs are re-encoded, which takes a few minutes per minute of video.
Did a file not convert correctly? E-mail [email protected], ideally with a small sample file, and it will be fixed.
Key facts
- Input: AVI (.avi). Output: MP4 (.mp4).
- Your files are not uploaded: the work is done in your browser, on your own device.
- File size: up to 2 GB per file (the limit of the browser's WebAssembly memory).
- Needs a current browser (Chrome, Edge, Firefox or Safari) on a computer, tablet or phone; nothing to install.
- Free to use, with no sign-up.
AVI to MP4: why convert
AVI files are often memories: clips from a digital camera of the 2000s, transfers from a MiniDV camcorder, old dashcam recordings, films saved as DivX or Xvid, or exports from Windows Movie Maker. Today's phones, Macs, TVs, browsers, Google Photos and social networks often cannot play them, or play the sound without a picture. This converter reads the AVI in your browser and writes an MP4 with H.264 picture, the codec every device understands. Motion JPEG clips from old cameras usually become many times smaller in the process. MP3 sound is copied as it is, and uncompressed or other sound is converted to AAC. Family videos stay on your own computer: nothing is uploaded, and there is no watermark or limit on how many files you convert.
How to convert AVI to MP4
- Drop the AVI file in the box, or click to choose it.
- Check the codecs shown; H.264 can be copied, other video is converted to H.264.
- Click Convert to MP4, wait for the progress to reach 100 %, and save the MP4.
What changes when you convert
Interlaced camcorder video
DV and other camcorder recordings are often interlaced, which can show fine horizontal lines on moving edges. The converter keeps the picture as it is and does not deinterlace; most players handle it, but a desktop program like HandBrake can deinterlace if the lines bother you.
Old camera clips are large
Digital cameras from about 2000 to 2010 often recorded Motion JPEG in AVI, one JPEG picture per frame. As H.264 MP4 the same clip is typically five to ten times smaller with no visible loss.
Sound without picture
If an AVI plays sound but shows a black screen on your computer, the player lacks the video codec (often DivX or Xvid). The converter has those decoders built in and writes a picture every player can show.
Files larger than 2 GB
The browser can work with files up to 2 GB. Very long AVI captures from a camcorder can be bigger; use the desktop program HandBrake or FFmpeg for those.
About the formats
AVI
AVI (Audio Video Interleave) is Microsoft's video format from 1992. It was the standard for camcorders, early digital cameras and downloaded films in the DivX and Xvid era, and old family videos and dashcams still use it. Inside are often MPEG-4 Part 2 (DivX, Xvid), Motion JPEG or DV video with MP3 or uncompressed sound, which phones, browsers and most websites no longer play.
- AVI was introduced with Video for Windows in November 1992.
- Many digital cameras from about 2000 to 2010 recorded Motion JPEG in AVI, which makes very large files.
- The original AVI format cannot be larger than 2 GB; the OpenDML extension (1996) removed that limit.
- DivX and Xvid are both MPEG-4 Part 2 video, the generation before H.264.
MP4
MP4 (MPEG-4 Part 14) is the most common video file format. Phones, cameras, YouTube, WhatsApp and every computer and TV use it. An MP4 is a container: the picture inside is usually compressed with H.264 or H.265 (HEVC) and the sound with AAC, and the same file can also hold subtitles, chapters and a cover image.
- The format was standardised in 2003 and is based on Apple's QuickTime format, which is why MP4 and MOV files are so alike.
- H.264 video with AAC sound plays on practically every device made in the last 15 years.
- A minute of phone video in 1080p is typically 100–200 MB; in 4K it is often 350–500 MB.
- The "faststart" layout puts the index at the beginning, so a video can start playing before it is fully downloaded.
Frequently asked questions
Is my AVI file uploaded?
No. The conversion runs with FFmpeg inside your browser, on your own device. Your home videos are not sent anywhere.
How long does it take?
AVI files with H.264 inside are copied in seconds. DivX, Xvid, Motion JPEG and DV are encoded again: plan for one to five minutes per minute of video on a laptop, less for small old camera clips.
Will the quality be the same?
The picture is encoded with H.264 at a high quality setting, so it looks the same to the eye. It cannot get sharper than the original AVI.
Does it work for DVD files?
Unprotected .mpg files from a DVD recorder or a DVD you made yourself can be converted with the MP4 converter. Commercial DVDs are copy-protected and cannot be read.