Merge Videos
Join several videos into one MP4 — without re-encoding when they share the same encoding
Click or drop videos hereChoose videos (add them in the order you want, or reorder below)
About Merge Videos
With Merge Videos, you can join two or more videos, one after the other, into a single MP4 in the order you set. The clips are joined by copy in your browser, with no upload and no re-encoding, only when they all share the same encoding: H.264 or HEVC video with AAC sound or none, the same size, frame rate, and encoder settings, as clips filmed one after another with the same phone settings can be. Otherwise, each clip is first sent to our video service and matched to the first one (its size, with black bars rather than stretching, its frame rate, stereo sound), then joined the same way.
How to merge videos into one MP4
- 1Choose or drop two or more videos; you can add more afterward.
- 2Set the order with the ↑ and ↓ buttons next to each video, and remove one with ✕.
- 3Click "Merge videos"; the number on the button is the count of clips.
- 4Wait while the page reads the clips and, when they differ, uploads and matches each one on our video service.
- 5Play the merged video and click "Download" to save the MP4, named after the first clip with -merged.
Formats and limits
- Input formats
- MP4, M4V, MOV, WebM, MKV, AVI, WMV, FLV, OGV, 3GP, 3G2, MPG, MPEG, TS, MTS, M2TS; at least two files
- Output
- One MP4: H.264 or HEVC copied as is when the clips are alike, H.264 with AAC sound when they had to be matched
- Maximum total size
- 2 GB on a computer, 700 MB on phones and tablets; clips sent for matching also face our video service's own size limit
- Frame rate
- That of the first clip when clips are matched, at most 60 frames per second
- Usage limits
- None when the clips are alike; otherwise each clip counts as one job in the hourly and daily limit of your internet connection on our video service
Where your file is processed
Only when all the clips are alike is nothing uploaded: ffmpeg.wasm, a copy of ffmpeg loaded from unpkg.com, joins them inside this tab. Otherwise, every clip is sent to our video service on Railway, matched, and downloaded back; the service erases each original when its matching ends and the matched copy once this page has fetched it. The final join always happens in this tab. An error shown on the page is reported to us as cleaned text with its error type, the tool name, and your browser and version, without the videos.
Frequently asked questions
Can I merge videos from different phones or cameras?
Yes. Clips that differ in size, frame rate, or format are matched to the first clip on our video service: same size with black bars where the shape differs, same frame rate, stereo sound, and silence added to a silent clip. They are then joined without a second re-encoding.
Does merging lose quality?
No, when the clips are alike: they are copied, not re-encoded, and nothing is uploaded. Yes, slightly, when they differ: each clip is encoded once in H.264 before the join, at the service's high-quality setting or, if that would make it larger than the original, with stronger compression; its sound becomes stereo AAC.
Which video sets the size of the result?
The first one in the list. Its width, height, and frame rate are applied to the others; a clip of another shape gets black bars and is never stretched. Move the clip you want as the reference to the top with the ↑ button.
How large can the videos be?
2 GB in total on a computer and 700 MB on phones and tablets, because the merged file is built in the browser tab's memory before you save it. Clips that must be matched also go through the size limit of our video service.
Tips and tricks
- ✓On iPhone, pick the clips in the Files app rather than the Photos library: iOS shrinks videos picked from Photos before the page receives them.