Put two videos side by side
Show two clips together in one frame, left and right or top and bottom. Done on this device, and nothing is uploaded.
- Nothing is uploaded
- Works offline after first visit
- Open source
- No watermark. The limit is your device’s memory (phones hold less): two long HD clips may need a computer.
Lets you put two videos next to each other in one frame, left and right or one above the other, and saves the result as one MP4. It is free, needs no account and adds no watermark, and your videos are not uploaded: your browser decodes both clips and draws them together inside this tab. You choose whose sound is kept (or both, or none) and whether the result ends with the shorter clip or holds its last frame. After one visit and a short wait the page works offline.
Done
Free, no ads. Support StayPut
Open the network tab. Your files never appear in it.
Add files and run the tool to see every request this tab makes.
Your files are processed on this device and never sent to a server. Reload the page to clear everything from memory.
A worked example
You filmed the same dance twice, once yesterday (A) and once today (B), both 1280×720 and 10 seconds long. Left | Right gives a 2560×720 video, 10 seconds long, with A on the left and B on the right and A’s sound. Top | Bottom gives 1280×1440 instead, which suits a phone screen held upright.
If B is only 6 seconds long, the result ends at 6 seconds by default. Choose to run to the longer clip and B holds its last frame until A has finished.
What this page does and does not do
- It puts two videos together in one frame. It does not do three or more videos, or picture-in-picture with one clip small on top of another.
- Want to cut one video into parts? Use Video splitter.
- To join clips one after the other instead, use Merge videos.
- The result is an MP4 at most 3,840 pixels wide, and every cell is an even number of pixels. Clips with different frame rates are brought to the faster one, up to 60 frames a second.
How it works
- Drop two videos (MP4, MOV, WebM or MKV), or pick one for slot A and one for slot B.
- Choose Left | Right or Top | Bottom, how the clips fit, whose sound to keep and how long the result runs. The page shows the size, the length and the memory it needs.
- Press Put side by side. The result is one MP4, saved as the name of video A with -side-by-side.
In your browser, not on a server
Mediabunny (MPL-2.0) reads the MP4, MOV, WebM or MKV clips in your tab. For every frame of the result, your browser decodes the picture each clip shows at that moment (WebCodecs), draws the two side by side or stacked on a canvas, and encodes the canvas into an MP4, H.264 where available and VP9 or AV1 otherwise. The sound of the clip you chose, or a mix, is decoded by your browser and encoded as AAC.
Compared with upload-based tools: Online split-screen makers upload both clips, cap free files at a few hundred megabytes and often put their watermark on the result. Here the clips never leave your device, and there is no watermark.
Verify it yourself. Give the page a short while after one visit to save itself for offline use, then turn off Wi-Fi or switch to airplane mode and run the tool again. Or open your browser's developer tools (F12, or Cmd-Option-I on a Mac), pick the Network tab, and watch it while you convert. The panel above does the same count for you.
Questions
How do I put two videos side by side?
Drop both videos (the first is A, the second is B), choose Left | Right, and press Put side by side. You get one MP4 with the two clips next to each other, nothing uploaded. Swap A and B if they are the wrong way round.
What if the two videos have different frame rates?
They are retimed to the output rate, which is the faster of the two (up to 60 frames a second). For every frame of the result, the page takes the picture each clip shows at that moment, so a 24 fps clip and a 30 fps clip stay in step: the same second of each sits in the same frame.
What happens to the sound?
You choose: the sound of video A (the default), the sound of video B, both mixed, or none. A mix is lowered only if it would otherwise clip. A clip with no sound gives a silent result for that choice.
What if the two videos are different lengths?
By default the result ends with the shorter video. Choose to run to the longer one and the shorter video holds its last frame until the end. Sound longer than the result is cut.
Can I put three videos together, or one inside another?
No. This page puts exactly two videos in one frame, side by side or one above the other. It does not do three or more videos, picture-in-picture or other layouts.
Will it work on my phone?
It can, but a phone has less memory than a computer and two HD streams are decoded at once. The page shows the memory estimate before you start. On a phone, more than about 200 MB of video in total is likely to fail, so trim the clips shorter first or use a computer. Jobs too big for the device are refused before any encoding starts.
Are my videos uploaded?
No. Your browser reads both files from your device, decodes them with WebCodecs and encodes the result in this tab. Open the network tab, run it, and your videos are not among the requests.
More video and audio tools
Repeat video
Save a clip repeated end to end as one longer file, by count or by length. Done on this device, never uploaded.
Add audio to video
Put music or a voice-over on a video, or replace its sound. The picture is copied as it is, and nothing is uploaded.
Reverse video
Make a clip play backwards, for a rewind effect, a boomerang or a laugh. Done on this device, never uploaded.
Video to JPG
Turn a video into still images: a few good frames or every single one. Done on this device, never uploaded.