Why convert AVI to MP4?

AVI is an older Microsoft container with large file sizes and patchy support on phones, tablets and modern players. MP4 plays everywhere and packs the same video into a much smaller file using efficient H.264 compression.

Why is my AVI file so large?

AVI dates from before modern compression and often stores video in old codecs like DivX or XviD with little efficiency. Re-encoding to H.264 MP4 typically cuts the size by half or more with no visible quality loss.

My AVI won't play or shows a "missing codec" error — will MP4 fix that?

Yes. AVI relies on whatever codec was used to create it, so a player lacking that exact codec shows an error or plays sound with no picture. Converting to standard H.264 MP4 removes the codec guesswork — it simply plays.

Will my old AVI video lose quality?

The MP4 keeps the original resolution and frame rate. Any difference from re-encoding is minimal at the high-quality settings used here, and it is usually outweighed by the smaller size and reliable playback.

Can I play the MP4 on my phone and smart TV?

Yes — that is the main reason to convert. H.264 MP4 is the format built into iPhones, Android phones, smart TVs and streaming sticks, none of which reliably handle old AVI files.

I have old camcorder or webcam AVI clips — can I convert those?

Yes. AVI was the default for camcorders, webcams and screen-capture tools in the 2000s. Converting those clips to MP4 makes them easy to store, share and play on today's devices.

Will the audio stay in sync?

Yes. The audio track is re-encoded alongside the video and kept aligned, so speech and sound stay matched to the picture even in long clips.

Convert AVI to MP4 Online

Modernize old AVI files — MP4 plays everywhere and compresses much more efficiently.

or drag & drop them here · images, video, audio and documents · up to 2 GB

How to convert AVI to MP4

Click "Choose Files" and select your AVI file, or drag & drop it onto the page.
Make sure MP4 is selected as the target format.
Click "Convert" and wait a few seconds.
Download your new MP4 file.

Why Converters.live?

Free and unlimited — convert as many AVI videos to MP4 as you need, no daily limits.
Files up to 2 GB, processed with the same FFmpeg engine professional tools use, keeping video and audio in sync.
Your video files are deleted from the server immediately after conversion — nothing is stored.

Frequently asked questions

Why convert AVI to MP4?: AVI is an older Microsoft container with large file sizes and patchy support on phones, tablets and modern players. MP4 plays everywhere and packs the same video into a much smaller file using efficient H.264 compression.
Why is my AVI file so large?: AVI dates from before modern compression and often stores video in old codecs like DivX or XviD with little efficiency. Re-encoding to H.264 MP4 typically cuts the size by half or more with no visible quality loss.
My AVI won't play or shows a "missing codec" error — will MP4 fix that?: Yes. AVI relies on whatever codec was used to create it, so a player lacking that exact codec shows an error or plays sound with no picture. Converting to standard H.264 MP4 removes the codec guesswork — it simply plays.
Will my old AVI video lose quality?: The MP4 keeps the original resolution and frame rate. Any difference from re-encoding is minimal at the high-quality settings used here, and it is usually outweighed by the smaller size and reliable playback.
Can I play the MP4 on my phone and smart TV?: Yes — that is the main reason to convert. H.264 MP4 is the format built into iPhones, Android phones, smart TVs and streaming sticks, none of which reliably handle old AVI files.
I have old camcorder or webcam AVI clips — can I convert those?: Yes. AVI was the default for camcorders, webcams and screen-capture tools in the 2000s. Converting those clips to MP4 makes them easy to store, share and play on today's devices.
Will the audio stay in sync?: Yes. The audio track is re-encoded alongside the video and kept aligned, so speech and sound stay matched to the picture even in long clips.

About AVI and MP4

Key things to know before you convert AVI to MP4:

AVI

AVI is a 1992 legacy container: poor codec support, no streaming, big files. Convert old AVI archives to MP4 unless specific software demands AVI.

MP4

MP4 with H.264 is the universal video format: phones, TVs, browsers, editors and messengers all play it. When in doubt, send MP4.

Related conversions

WEBM→MP4 MOV→MP4 MKV→MP4 GIF→MP4 WMV→MP4 FLV→MP4 M4V→MP4 AVI→MP3