Two clips, one frame — resize, place, blend audio — Free, No Upload
Layering one video over another is the basis of reaction videos, webcam-over-gameplay clips, side commentary and split-screen edits. This page covers how to composite a second video on top of a base video in the browser: scale it down to a corner, set how it blends, decide which soundtracks survive, and export the combined clip without uploading either file.
Drop a base video, add a second video on top, size and position it, then export the composite locally — no watermark, no upload.
Open the Video Overlay tool →The base video becomes the background and defines the final dimensions and length. The overlay video plays on top, scaled to whatever size you choose and anchored to a position you pick. Each frame, the tool draws the base picture, then draws the overlay's current frame over it, and records the result. Both clips advance in real time, so motion in the overlay stays in sync with the moment it plays.
For a classic floating insert, set the overlay size to roughly a quarter or a third of the width and snap it to a corner with a margin. For a stacked or split look, make the overlay larger and place it on one half. The custom position option lets you put it at any X/Y percentage when a preset corner isn't quite right. Opacity lets you ghost the overlay over the footage — useful for soft transitions or watermark-style clips.
Two videos mean two soundtracks, and you rarely want both at full volume. Keep the base audio for the main action, and toggle Mix overlay audio only when the second clip's sound matters — for example a voice reacting to muted gameplay. If you just want the visuals of the overlay, leave its audio off and the base track plays alone. When you choose a 2× or 4× fast export, audio is dropped on both layers so the render finishes quicker.
The overlay doesn't have to run the whole time. Set the timing to a window so the second clip appears only between two seconds — a cutaway that drops in for five seconds, then leaves the base video clean again. Turn on the optional fade so it eases in and out instead of popping. If you want the overlay present throughout, leave the timing on Whole video and, for a short overlay, enable Loop so it repeats until the base ends.
Both videos are read with local blob URLs and composited in your browser — nothing is uploaded. Because the output is recorded live from the canvas, expect the render to take about as long as the base clip at 1× speed, and use the fast modes when you can spare the audio.
Yes. Use the gameplay as the base video, add the webcam clip as the overlay, size it to about 25% and place it in a corner. Keep the webcam audio with Mix overlay audio if you want your commentary.
The base video. The overlay is looped if it's shorter and cut off if it's longer.
If it's a WebM with an alpha channel, yes — transparent areas let the base show through. Most regular MP4s have no transparency and appear as a solid rectangle.
No. Both clips stay on your device and are processed locally in the browser.