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Merge AVI Files into One MP4

Join old AVI clips from a camcorder or digital camera into one MP4 that plays on today's phones and TVs. The conversion runs on your computer, not on a server.

Convert a video
Works with
  • MP4
  • MOV
  • AVI
  • VOB
  • Runs in your browser
  • 100% free
  • Private

Popular tools

How to merge AVI files

  1. Find your AVI files

    Copy the .avi clips off your camera card or old hard drive, then drop them onto the page.

  2. Sort them by scene

    Drag the clips into order. Camera files often have numbered names like MVI_0001.AVI, which helps you keep the order you filmed them in.

  3. Convert and download

    Click Merge & convert to MP4. AVI is always fully converted, so give it a few minutes, then preview and save.

Why people use Adapterry

  • Nothing is uploaded

    Your videos are processed in your browser and never leave your device.

  • No account needed

    Open the page and start. No email, no password.

  • No watermark

    Your MP4 comes out clean, with no logo stamped on it.

  • Works offline

    Once the page and video engine have loaded, you can keep working without an internet connection.

Supported formats

Add MOV, AVI, VOB or MP4 files, or a mix of them. You always get back one MP4 with H.264 video and AAC audio.

InMP4MOVAVIVOBOutMP4
See all formats

Why AVI needs converting

AVI is an older format from the Windows PC era. Many AVI files use DivX or Xvid video (MPEG-4 Part 2) with MP3 audio, which a lot of phones, smart TVs and editing apps won't open.

Adapterry re-encodes every AVI clip to H.264 video and AAC audio. Even if your clips came from the same camera, they always go through full conversion, so expect it to take longer than a quick MP4 join.

Questions and answers

Why won't my AVI file play on my phone?

Many AVI files use DivX or Xvid video and MP3 audio, which phones often don't support. Converting to MP4 with H.264 and AAC fixes that.

Can I merge AVI clips from different cameras?

Yes. Each clip is converted to the same format, and the final size follows the first clip. Clips with a different shape get black bars.

Why is merging AVI slower than MP4?

AVI files are always fully re-encoded, even when they match each other. MP4 clips with matching settings can skip that step.

My camcorder AVI has no sound. Will it still merge?

Yes. Adapterry adds silent audio to clips without sound, so they join with the rest.

Can I add MP4 or MOV clips to an AVI merge?

Yes. Mix any of the supported formats in one list and they all come out as one MP4.