Merge videos
Join several MP4, MOV, WebM or MKV clips into one video, in the order you add them. Clips from the same camera are joined without re-encoding; different ones are fitted to the first clip’s size and saved as MP4.
Process locally
Files stay in this browser session. Closing or clearing releases them.
Choose files
MP4, MOV, WebM, MKV, at least 2, up to 10
Drop files here, or
Adjust settings
Optional: Clips of another shape
Run
Processes in this browser; cancel at any time
About this tool
Merge several video clips into one file, in the order you put them: MP4, MOV, WebM and MKV, 2 to 10 clips of up to 80 MB in total. The clips are joined in your browser and not uploaded.
When every clip has the same container, codec settings, picture size and sound settings, as clips from the same phone or camera usually do, they are joined by copying, without re-encoding: fast, lossless and in the same format. Otherwise all clips are re-encoded into one MP4 (H.264 video with AAC sound) at the size of the first clip, and clips of another shape are fitted with black bars or cropped to fill the frame.
How to use it
- Choose or drop 2 to 10 MP4, MOV, WebM or MKV clips, up to 80 MB in total.
- Use the up and down arrows in the file list to set the order; clips are joined from top to bottom.
- If the clips differ in shape, choose under “Clips of another shape”: “Fit inside, with black bars” or “Fill the frame, cropping the edges”.
- Select Run, play the joined video in the preview and download it. It is named after the first clip with “-joined” added.
Formats and limits
- Input
- MP4, MOV, WebM, MKV, 2 to 10 files
- Output
- MP4, MOV, WebM, MKV
- Size limit
- 80 MB per file
- Settings
- Clips of another shape (Fit inside, with black bars, Fill the frame, cropping the edges)
- Privacy
- Files stay in the current browser session. No file bytes are uploaded.
- Price
- Free, no sign-up
Common questions
Is merging lossless?
When the clips match, yes: their video and sound are copied into one file without being decoded, and the result keeps their format. This is the usual case for clips filmed on the same phone or camera with the same settings. Clips that differ in format, codec, size or sound settings are re-encoded into an MP4 instead.
What happens to clips of different sizes or orientations?
The joined video takes the size of the first clip. A clip of another shape, such as a vertical clip in a landscape video, is either fitted inside with black bars or scaled to fill the frame with its edges cropped, as you choose under “Clips of another shape”. Put the clip whose size you want first.
What if a clip has no sound?
Silence of the same length is put in its place, so the sound of the later clips stays in sync with their picture.
Can I add transitions between clips?
No. The clips are joined end to end, without fades or transitions. To cut unwanted parts first, use “Trim video” on each clip.
Which browsers can merge videos?
Re-encoding clips that differ needs a browser with WebCodecs: current Chrome and Edge, or a recent Safari or Firefox. Each run may take at most 30 minutes.
Related tools
Extract audio from video (MP4 to MP3)
Take the sound out of MP4, MOV, MKV or WebM video and convert it to MP3, M4A, OGG, WebM or WAV, or keep the track unchanged in its own container, optionally trimmed. Files are not uploaded.
Join audio files
Merge MP3, M4A, WAV, OGG, FLAC and other audio files into one track, in the order you add them, end to end, with a pause between them or with a cross-fade. Save the result as MP3, M4A, OGG, WebM or WAV.
Compress video
Make MP4, MOV, WebM and MKV videos smaller by quality level, target file size or bitrate, with an optional resolution limit. Encodes H.264 (MP4), VP9 (WebM) or AV1 (MP4) with the browser’s own encoder.
Convert video format
Convert between MP4, WebM, MKV and MOV; MP4 and MOV get H.264 video and AAC sound so any player opens them, and other formats copy streams when they can. Scale down, remove the sound or trim at the same time. Encoding uses the browser.
Crop video
Crop the picture of MP4, MOV, WebM and MKV videos to one region, in pixels or percent, to cut off black bars, a watermark corner or anything outside the subject. The sound is kept as it is.
Remove background noise from video
Clean the sound of MP4, MOV, WebM and MKV videos: hum, hiss, wind, fans and room noise are removed from speech by RNNoise in your browser. The picture is copied as it is; only the sound is encoded again.