Free Online Video Merger

About the Video Merger

Joining several short recordings into one continuous video usually means installing a desktop editor or uploading files to a service. This merger takes a different approach: it plays your clips in the order you choose, paints each frame onto a canvas, mixes the audio, and records the result with the browser's own media encoder. No file is sent anywhere, and no plugin or command-line tool is required. Add your clips, arrange them with the arrow buttons, and press merge.

Ordering clips

Every added clip appears in a numbered list showing its name, duration, and size. Use the up and down arrows to move a clip earlier or later, or the remove button to take it out. The merge always follows the list from top to bottom. Clip durations are read when the file is added, so the total length and the estimated output size are shown before you start.

Different sizes and shapes

Clips recorded on different devices rarely share the same resolution. The merger picks a canvas large enough for the biggest clip, capped at 1920 pixels on the long side to keep memory use reasonable. Smaller clips are scaled to fit inside that canvas and centered with black bars, which preserves their aspect ratio instead of stretching them. Audio from every clip is routed through the Web Audio API and recorded together with the picture.

Real-time recording

Browsers do not expose a general-purpose timeline encoder in JavaScript. That is why the tool records in real time: a three-minute total takes roughly three minutes. The tab must stay in the foreground, because background tabs can pause animation frames and drop captured frames. Very long merges are also limited by the memory available to the page, since encoded chunks accumulate until the recording finishes.

Output format

When the browser can record H.264 inside an MP4 container, the download is an .mp4 file. Otherwise the tool records WebM and labels the result clearly. The actual codec used is shown in the result card rather than assumed, so you know exactly what you are getting before you share it.

Frequently asked questions