OneTaskBy Tim King · Updated
Video Merger
Join Video Clips Into One Online, No Upload
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How the Video Merger works
This video merger joins two or more clips into one file, end to end. Drop in the videos, choose the order and the frame size, press Render and download a single video. Clips of different shapes are fitted with black bars or cropped to fill. Everything runs in your browser, so nothing is uploaded.
Video merger: one file instead of a folder of clips
Phones and cameras split recordings into separate files every time you press stop. Sharing them as a folder means the viewer has to play each one in turn, in the right order. Merging them gives one file that plays straight through and uploads once.
Choosing the order
"As picked" keeps the order the files arrived in. "By file name" sorts them by name with numbers read as numbers, so "clip2" comes before "clip10". Camera files such as GX010231 and GX010232 are already numbered in recording order, so sorting by name is usually right for them.
Mixed shapes and sizes
The merged video has one frame size. Leave it on "Same as the first clip", or pick a fixed size such as 1920 × 1080 for landscape, 1080 × 1920 for vertical video or 1080 × 1080 for a square post. A clip with a different shape is either fitted inside the frame with black bars or scaled up and cropped to fill it.
How the merge works
The page plays each clip in turn and records it onto a canvas, so a merge takes as long as the clips play. The result is WebM in Chrome, Edge and Firefox and MP4 in Safari. Sound from each clip is carried across unless you remove it. To join audio files only, use the audio joiner, and to trim each clip first, use the video trimmer.
FAQ
Why does merging take as long as the videos?
The browser has no built-in way to copy video frames between files, so the page plays every clip and records the canvas in real time. A two-minute set of clips takes about two minutes to merge.
Can I join clips with different resolutions?
Yes. Every clip is scaled into the chosen frame size. Fit keeps the whole picture with black bars where the shapes differ, while Fill crops the edges so the frame has no bars at all.
Is there a limit on how many clips I can merge?
There is no fixed limit, but each clip is held in memory while it plays, and very long merges use more memory. For dozens of clips or over an hour of footage, merge in smaller batches first.
Why is the merged file a different format from my clips?
Browsers record to WebM, except Safari which records MP4. The pictures and sound are re-encoded on the way, so the output format follows the browser rather than the original files.
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Audio Joiner
Merge several audio files into one, in order, with optional gaps.
Video Resizer
Scale a video down (or up) to a standard resolution.
Video Fade
Fade a video in from black or white and out again.