Combine multiple videos into one MP4. Free, private, runs in your browser.
100% private — your files and text never leave your browser. All processing happens locally on your device.
Choose files
or drop them here
Mode
Transcode quality
Merge Videos combines clips locally with FFmpeg.wasm. Add the files, move them into the order you want, and export one MP4. No clip is uploaded or processed by a Convertful server.
Video merging is easiest when every clip uses compatible codecs, dimensions, frame rates, and audio settings. Auto mode tries a fast stream copy first, then falls back to transcoding when the clips need to be normalized.
Merging several large clips can be one of the heaviest browser media tasks. The cancel button terminates the FFmpeg worker so you can recover quickly, remove clips, or retry with fewer inputs.
Yes. After adding clips, use the up and down controls to set the merge order before creating the final MP4.
No. Each clip is written to FFmpeg.wasm in your browser, merged locally, and returned as a local MP4 download.
Copy mode works when clips have compatible streams, codecs, time bases, and dimensions. If they differ, Auto mode uses transcoding for a more reliable MP4.
The browser has to hold multiple video inputs, FFmpeg assets, and the output file in the current tab. Large clips can exceed available memory.
Yes. Cancel terminates the FFmpeg worker. You can then remove clips, reorder, or retry with transcode mode or smaller files.