Video Merger (Join Multiple Videos into One)
Pick several video files, put them in the order you like, and join them into a single video. The resolution and frame rate follow the first clip, and clips of a different size are fitted in with black bars so nothing is cropped. If some clips have no sound, those parts are filled with silence so the audio stays in sync. It uses your browser’s built-in video encoder (WebCodecs), so your files are never uploaded. To speed up or slow down a single clip, use the Video Speed Changer; to convert formats or trim, use the Video & Audio Converter; to join audio files only, use the Audio Merger.
🔒 Runs in your browser · Your data is never sent to a server
You can also drag and drop files here to add them
Limits: up to 10 clips, 300.0 MB per clip, 600.0 MB in total, 10:00 total length
Videos to merge (joined from top to bottom)
No videos added yet.
Audio is converted to 48 kHz stereo. Clips without audio become silent sections. If none of the clips has audio, the result is video only.
Result
How to use
- Choose videos with "Add video files (multiple allowed)" (drag and drop also works).
- Use the "Up" and "Down" buttons in the list to set the order. The first video sets the output size and frame rate.
- Pick the "Output format" and "Quality". If you do not need sound, check "Remove audio (video only)".
- Press "Merge", then save the result with "Download" when it finishes.
Notes
- The resolution (width × height) and frame rate of the first video set the output. Other clips are fitted to that size, so a different aspect ratio gets black bars, and a different frame rate means frames are dropped or repeated. Put the clip you want to base the output on first.
- Clips without audio are filled with silence for their length. If none of the clips has audio, the result has no audio either. Clips with different audio formats are converted to 48 kHz stereo before joining.
- Every clip is re-encoded, so some quality is lost. "High" keeps the loss small but makes a larger file.
- To keep things manageable, you can merge up to 10 clips, 300 MB per clip, 600 MB in total, and 10 minutes in total length. The output is built in memory, so long or high-resolution videos can take a while or fail when memory runs out.
- Keep this tab open and in the foreground while merging. Some browsers slow down or pause background tabs.
- Available input and output formats vary by browser. MP4 (H.264) output works best in Chrome, Edge and Safari, WebM output in Chrome and Edge, and Firefox may have limited encoding support.
- Subtitles, chapters and extra audio tracks are not carried over. Transitions such as cross-fades and text overlays are not supported.
- All processing happens in your browser; the files you choose are never sent to a server.
Glossary
fps (frame rate)
The number of frames shown per second. This tool matches everything to the first video’s fps, dropping or repeating frames in clips with a different rate.
Letterbox (black bars)
Black bars added above and below, or at the sides, so a video with a different aspect ratio fits without being cropped. Clips whose aspect ratio differs from the first video get them here.
Re-encoding
Decoding a video and compressing it again. It is needed to join clips of different formats or sizes, at the cost of a small quality loss.
WebCodecs
A standard browser API for compressing and decompressing video and audio. This tool uses it to merge files inside your browser.
FAQ
Can I merge videos with different resolutions or frame rates?
Yes. Everything is matched to the first video’s resolution and frame rate (fps). Clips with a different size or aspect ratio are fitted in with black bars instead of being cropped, so put the clip you want to base the output on first in the list.
What happens to clips that have no audio?
Those sections are filled with silence, so the audio of the surrounding clips stays in sync with the video. If none of the clips has audio, the output has no audio track.
Is there a limit on the number or length of videos?
Up to 10 clips, 300 MB per clip, 600 MB in total, and 10 minutes in total length. The limits are strict because everything is re-encoded in your browser and built in memory. If you hit them, lower "Resolution (max height)" or merge in smaller groups.
Does merging reduce the video quality?
Slightly, because every clip is re-encoded. Choosing "High" quality keeps the loss small but makes a larger file.
Are my videos uploaded to a server?
No. Merging runs inside your browser using WebCodecs, and the files you choose are never sent anywhere.
Share this page