AVI to MP4 Converter

Turn legacy AVI video into MP4 that plays on phones, browsers, and TVs. Free, in your browser, with no signup and no watermark.

Select AVI file →

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Choose Files

Click or drag and drop to upload files

We support most file types including: MP4, MOV, WEBM, AVI, MP3, WAV, PNG, JPEG, GIF, MKV, PDF, FLAC, TIFF!

EchoWave is used by creators, marketers, educators, and businesses to convert and edit media online.

Updated June 2026

AVI is an older Windows container, and the DivX or Xvid video inside it often refuses to play on phones, in browsers, or on smart TVs. Converting to MP4 re-encodes that video to H.264, the codec almost every device supports today. The result plays the same clip anywhere and is usually smaller, all free and right in your browser.

Free, no sign-upNo account, no trial

Runs in your browserNothing to install

Works on every devicePhone, tablet, laptop

No watermarkClean output, every time

How it works

How to convert AVI to MP4

1
Upload your AVI
Drag your AVI onto the converter or pick it from your device. Nothing to install.
2
Choose MP4 and convert
Select MP4 as the output and start. Free, with no sign-up and no watermark.
3
Download your MP4
Save the finished MP4, or open it in the editor to trim, crop, or resize it first.

Try it

Estimate your MP4

Pick a video bitrate and a length to see the MP4 file size before you convert.

Video bitrate

Length5 min

1 min30 min

Estimated MP4 size183MBSharp 1080p

An estimate. Real size varies with resolution, frame rate, and how much the picture moves.

The formats

AVI vs MP4

AVI

Audio Video Interleave

A legacy Microsoft video container

Type: Legacy video container
Holds: Older codecs like DivX or Xvid with MP3 or PCM audio
Typical size: Large for the quality it gives
Plays on: Windows and VLC, patchy on phones

Best for:Playing older Windows video files

MP4

MPEG-4 Part 14

The video format that plays everywhere

Type: Video container
Holds: H.264 video plus AAC audio, sometimes subtitles
Typical size: Large, it carries video
Plays on: Phones, browsers, TVs, almost any player

Best for:Watching and sharing video

Will it lose quality?

When the codecs already match MP4, the converter can change the container without re-encoding, so the picture stays identical.
When the video has to be re-encoded for MP4, a high bitrate keeps it visually close to the AVI.
Converting cannot add detail the AVI never had. The output is at best as good as the source.

Use cases

What people use it for

Play anywhereMake a clip your device supports

Video editorsGet footage your software accepts

Web videoUse a format browsers play

CourseworkHand in a standard video file

SharingSend a clip people can open

Troubleshooting

If something looks off

The MP4 will not play

Some players are picky about codecs. Try it in VLC, which opens almost anything, or convert again and let the converter re-encode the video.

The file got larger

A format change can shift the size, and re-encoding at a high bitrate adds overhead. Lower the bitrate or trim the clip for a smaller file.

Audio and video drift out of sync

Re-download the source and convert again. If a long recording drifts, splitting it into shorter pieces usually fixes the sync.

FAQ

AVI to MP4 questions

Is the AVI to MP4 converter free?

Yes. EchoWave converts AVI to MP4 with no signup, no file-count limit, no trial, and no watermark. Upload your AVI, convert it, and download the MP4 from your browser.

Why will my AVI not play on iPhone or Android?

Phones play MP4 natively but rarely support AVI, especially when the video uses older DivX or Xvid codecs. Converting AVI to MP4 re-encodes the video to H.264, which iPhone, iPad, and Android all play without an extra app.

How do I convert AVI to MP4?

Upload your AVI, choose MP4 as the output format, and start the conversion. When it finishes, download the MP4 or open it in the editor to trim, crop, or resize it first.

Will converting AVI to MP4 lose quality?

AVI to MP4 almost always re-encodes the video, because MP4 does not accept DivX or Xvid as-is. Exporting at a high bitrate keeps the result visually close to the source, but converting can never add detail the original AVI did not have.

Will the MP4 be smaller than the AVI?

Usually yes. AVI files made with older DivX or Xvid codecs are often inefficient, so re-encoding to H.264 frequently shrinks the file while keeping similar picture quality. The exact size depends on the bitrate you choose.

Can I convert AVI to MP4 on Mac and Windows?

Yes. The converter runs in any browser on macOS, Windows, Chromebook, and Linux, so you do not need Windows Media Player, VLC, or a desktop converter installed. There is nothing to download and no account to create.

Does the AVI to MP4 converter work on phones?

Yes. It runs in your mobile browser, so you can convert AVI to MP4 on iPhone, iPad, and Android, which is handy because those devices cannot open the AVI directly in the first place.

Can I convert large AVI files or several at a time?

Yes. Nothing caps how many AVI clips you push through, so a folder of DivX or Xvid videos can go one after another into MP4. A long, high-bitrate AVI uploads first and then re-encodes to H.264, so bigger recordings just need a bit more time.

What opens an MP4 file after converting?

Almost everything. MP4 plays in every browser, on every phone, on smart TVs, and in editors like iMovie, Premiere, and CapCut, so an MP4 is the safest format for sharing and uploading.

Is it safe to convert AVI to MP4 here?

Re-encoding a DivX or Xvid AVI to H.264 MP4 needs no account and no codec packs or desktop transcoder on your computer. Our security page explains how the AVI you upload and the MP4 you download for phones and browsers are handled.