Video Merger
Combine several clips into one video. Add your files, drag them into order, trim the start and end of each, choose the output size and format, then press Merge videos. Everything runs in your browser, with no upload and no watermark.
Clips 0
No clips yet. Add the videos you want to join. They play in the order shown here, top to bottom.
- Length
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- Output
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- Bitrate
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- Takes about
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Keep this tab open and visible: browsers slow down hidden tabs, which would drop frames.
How to use the Video Merger
- Add your clips by dropping them on the box or clicking to browse. You can add more at any time.
- Put them in order: drag a clip by its handle, or use the up and down arrows. Remove clips with the × button.
- Trim if needed: type a new start or end time for any clip, in seconds or m:ss.
- Choose the output: size, how to fit clips of other shapes, transition, frame rate, quality and format.
- Press Merge videos and keep the tab visible. Merging runs in real time, so 3 minutes of clips take about 3 minutes.
- Preview the result and press Download to save the merged video.
Merging clips of different sizes
Every clip is drawn onto one output frame, so clips from different phones and cameras can be combined. Choose how a clip that does not match the output shape is handled:
| Option | What happens | Best for |
|---|---|---|
| Fit (add bars) | The whole clip is shown, scaled to fit; the empty space is filled with the bar colour | Mixing portrait and landscape without losing any of the picture |
| Fill (crop edges) | The clip is scaled to cover the frame and the overflowing edges are cut off | A clean full-frame look, such as vertical videos for Reels, Shorts or TikTok |
| Stretch | The clip is resized to exactly the output size, changing its proportions | Clips that are already almost the same shape |
Pick the output size that matches where the video is going: 1920 × 1080 or 1280 × 720 for YouTube and most players, 1080 × 1920 (9:16) for vertical short-form video, and 1080 × 1080 or 1080 × 1350 (4:5) for feed posts. Match first clip uses the size of the clip at the top of the list.
How the merger works, and its limits
Browsers cannot cut and join compressed video streams directly, so the tool plays your clips one after another in hidden players, draws each frame onto a canvas, mixes the sound with the Web Audio API and records the result with the browser's built-in MediaRecorder. The recorder pauses while the next clip loads, so there are no frozen frames or gaps between clips.
- Merging runs in real time. The time needed equals the total length of the trimmed clips. Keep the tab visible so the browser does not throttle it.
- Every clip is re-encoded at the output size, frame rate and quality you choose, which is what makes mixing different formats and sizes possible.
- Output format depends on your browser: Chrome, Edge and Safari can usually create MP4 (H.264); Firefox creates WebM. The list only shows formats your browser supports.
- Only clips your browser can play can be merged. A clip that cannot be read is marked in the list and skipped.
- Memory: the merged file stays in memory until you download it, so very long projects need a computer with enough free RAM.
Tips for a smooth result
- Trim dead air at the start and end of each clip with the Start and End fields; times accept seconds (
12.5) or minutes and seconds (1:05). - Use Sort by name when your files are numbered, such as
clip1,clip2,clip10; numbers are sorted naturally. - A short fade through black (0.3–0.6 s) hides jumps in picture and sound between unrelated clips.
- Estimated size = (video bitrate + audio bitrate) × total length ÷ 8. At 1280 × 720, 30 fps and the Balanced preset that is about 15 MB per minute.
Frequently asked questions
How do I merge two videos into one?
Add both files, check that they are in the right order, and press Merge videos. The tool plays the clips one after another, records them into a single new file and offers it as a download when it finishes.
Can I merge videos with different resolutions or orientations?
Yes. Pick an output size, then choose Fit to show each clip whole with bars around it, Fill to crop it so it covers the frame, or Stretch. Portrait and landscape clips can be mixed this way.
Is there a watermark or file size limit?
There is no watermark and no account. The only limits are your device's memory and the time it takes, because the merged video is kept in memory until you download it.
Why does merging take as long as the videos?
Your browser re-encodes the clips in real time with its built-in MediaRecorder while playing them in the background. This keeps your files private, but 5 minutes of clips take about 5 minutes. Keep the tab visible so no frames are dropped.
Is the sound kept?
Yes. The audio of each clip is joined in order. Clips without sound simply add silence, and with the fade transition the sound fades out and in together with the picture.
Which formats can I merge?
Any video your browser can play, such as MP4 (H.264), WebM and most MOV files. You can mix formats in one project. HEVC (H.265), AVI and WMV files may not open in every browser.
Are my videos uploaded?
No. All clips are read, played and encoded inside your browser tab, and nothing is sent to a server.