Merge MP4 Files into One MP4
Join several MP4 clips into one file without uploading them. Clips from the same phone or camera are usually joined in moments, with no quality loss.
- MP4
- MOV
- AVI
- VOB
- Runs in your browser
- 100% free
- Private
How to merge MP4 files
Add your MP4 clips
Select all the MP4 files you want to combine. Hold Ctrl (or Cmd on a Mac) to pick several at once.
Arrange them
Drag the clips into place, or move them with the up and down buttons until they play in the right sequence.
Merge and save
Click Merge & convert to MP4. Play the preview, then download the combined file.
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.
When MP4 merging is instant
Most MP4s from phones and cameras use H.264 video and AAC audio. If every clip in your list has the same resolution, frame rate and audio settings, Adapterry copies the video data straight into the new file without re-encoding. It's quick and the picture stays exactly as it was.
If your MP4s come from different places, such as a phone clip and a screen recording, the settings won't match. Adapterry then re-encodes everything to one format. It takes longer, but you still end up with one consistent MP4.
Questions and answers
Why was my MP4 merge so fast?
Your clips shared the same codecs and settings, so Adapterry joined them without re-encoding. Nothing was recompressed, so there is no quality loss.
Why are some MP4 merges slower?
When clips differ in resolution, frame rate or audio, they have to be re-encoded to match. That work happens on your computer and can take a few minutes for long videos.
Can I merge MP4s recorded on two different phones?
Yes. The clips probably won't match, so Adapterry converts them to one shared format. The output uses the first clip's resolution, and other shapes get black bars.
Does the merged MP4 keep the sound from every clip?
Yes. Audio from every clip is kept and converted to AAC when needed. Clips with no sound get a silent track so they can still be joined.
Will the merged MP4 work on video sites?
The output is a standard MP4 with H.264 video and AAC audio. That is the format most video sites and social apps ask for.