Add files from where they live
Drop a AVI file on the box, browse for it, or import it from Dropbox, Google Drive or a link. You can add more files later, and each file gets its own result.
Free AVI to MP4 converter
Convert AVI to MP4 online. Add a file, confirm MP4 and download it. A single file needs no account.
Converting AVI to MP4 takes video out of a 1992 Windows container and puts it in one that phones, browsers and smart TVs actually open. The old DivX, Xvid or DV picture is normally re-encoded to H.264, so the file usually gets smaller. It cannot look better than the AVI you started with.
Transfers use HTTPS, and files converted on the free tier are deleted within 24 hours, so the result is not a long-term archive. Quality depends on the source file, so open the MP4 file once before you share it.
FromAVILossy
AVI (Audio Video Interleave)
A container Microsoft introduced in 1992 with Video for Windows. It usually holds older codecs such as DivX, Xvid, Motion JPEG or DV, with MP3 or uncompressed PCM audio, and it predates streaming and modern compression features.
ToMP4Lossy
MP4 (MPEG-4 Part 14)
The container used by current phones, cameras and streaming services. It was designed for codecs with reordered frames, variable frame rates and playback that starts before the download finishes, three things the older AVI structure handles awkwardly.
Why use indox to convert AVI to MP4?
Watch the job run
A progress bar shows the file moving through the conversion. If you picked the wrong file, cancel and start again.
Download it or hand it on
Save the MP4 file, copy a share link or convert it to another format. Free-tier output expires on its own after 24 hours.
What changes
- The codec is modernised. DivX, Xvid, Motion JPEG and DV are replaced by H.264 or a similar current codec, which is what hardware decoders in phones and televisions are built for.
- Size generally falls, sometimes dramatically. DV runs at roughly 13 GB per hour and Motion JPEG is similarly heavy, while H.264 reaches comparable quality at a fraction of that.
- Audio moves from MP3 or uncompressed PCM to AAC, the track type MP4 players expect, with a small saving in space and no obvious change to the ear.
- Playback over a network improves, because an MP4 can be arranged so a browser starts playing before the whole file arrives, something AVI was never designed for.
How do I convert AVI to MP4 online?
- 1
Add your AVI file
Drop your AVI file into the converter (or choose a file from disk).
- 2
Pick MP4 and press Convert
Confirm MP4 as the output format and start the conversion.
- 3
Download the MP4 file
Download the MP4 file when it is ready. Start another conversion anytime.
What do I get from indox's AVI to MP4 converter?
You upload a AVI file, indox converts it to MP4, and you download the result. A single file needs no account, and nothing is installed.
- No install and no account for a single file
- MP4 output you can download or share
- Progress while the job runs, with a cancel button
- Free-tier files are deleted within 24 hours
What are the limits for AVI to MP4?
Size
The upload box shows the live size limit before you add a file. Signing in raises it, and paid plans raise it further.
Formats
AVI in, MP4 out. Pick another output on the converter if you need a different format.
Privacy
Files are encrypted in transit over HTTPS and processed on indox infrastructure.
Deletion
Free-tier files are deleted automatically within 24 hours after the job finishes.
Limits worth knowing
- Quality is capped by the source. Blockiness, low resolution and noise in the AVI are carried into the MP4, and re-encoding adds a small further loss.
- Interlaced footage, typical of DV camcorders, can show comb-like lines on motion unless it is deinterlaced, and results vary with the source.
- Damaged or incomplete AVI files, common with interrupted downloads, may convert only partly or lose audio sync, since the index sits at the end of the file.
- Some AVI files contain rare or proprietary capture-card codecs that no general decoder understands, and those cannot be read at all.
What do the free and paid plans add?
Free
- All converters
- Daily credit refresh
- Email support
Basic
- Access to all features
- AI Extract & Doc Chat
- Priority conversions
- Email support
Highest priority
Premium
- Everything in Basic
- Highest priority queue
- Larger file limits
- Priority support
Pay-As-You-Go
- No subscription
- Credits never expire
- Opt-in auto-refill
- Access to all features
Which conversions are close to AVI to MP4?
MOV to MP4
iPhone and Mac video that plays anywhere
MKV to MP4
Video for phones, TVs and editors
WEBM to MP4
Browser recordings you can share
MP4 to MP3
The sound from a video
Related conversionsReverseMP4 to AVI
Who can use a AVI to MP4 converter?
When to use it
- Watching old downloaded or ripped videos on a phone, tablet or smart TV that refuses AVI.
- Rescuing DV camcorder captures and early digital camera clips before the software that opens them disappears.
- Posting an archived clip to a social network or video site that asks for MP4.
- Bringing legacy footage into a current editor that no longer ships decoders for DivX or Xvid.
Where can I read more about converting files?
Do it all with indox
No tool matches that search.
AVI to MP4 FAQs
Why won't my AVI file play?
Most often the device lacks a decoder for the codec inside, not for AVI itself. AVI is only a wrapper, and its usual contents (DivX, Xvid, Motion JPEG, DV) are formats that phones, browsers and many smart TVs dropped or never supported. Converting swaps those for H.264 and AAC, which virtually all current hardware decodes.
Does converting AVI to MP4 reduce quality?
Slightly, in most cases, because the picture is decoded and compressed again with a different codec. With a reasonable output size the difference is hard to see, since H.264 is far more efficient than the codecs AVI files typically use. What you will not get is an improvement: softness and artefacts from the original stay.
Will the MP4 be smaller than the AVI?
Usually, and the saving depends on the original codec. Camcorder DV and Motion JPEG files shrink enormously, often to a tenth of their size or less. An AVI already compressed with DivX or Xvid is fairly compact, so the reduction is modest, and it can even grow slightly if the new encode targets higher quality.
Can AVI be converted to MP4 without re-encoding?
Rarely in a useful way. Copying the streams untouched only works when the AVI happens to hold video and audio that MP4 accepts, and the common DivX or Xvid content, although technically MPEG-4 video, is still refused by many MP4 players. For dependable playback the video generally needs re-encoding to H.264.
Why does my converted video have horizontal lines on moving objects?
Those lines are interlacing from the original recording. DV camcorders and television captures stored each frame as two fields taken a fraction of a second apart, which old tube televisions blended naturally. On a progressive screen the fields show as a comb pattern wherever something moves. Deinterlacing removes it, at some cost in vertical sharpness.
Is AVI still worth keeping?
As an original, yes, as an everyday format, no. Keep the untouched AVI if it is a first-generation capture, since every re-encode loses a little and a better conversion may be possible later. For watching, sharing and uploading, MP4 is the practical choice because support for AVI's codecs keeps shrinking with each new device.