What This Merger Does — and What It Does Not
This tool rebuilds one video from its own parts. If someone sent you `holiday.mp4.001` through `holiday.mp4.004`, or a zip full of `part01`, `part02` files, this is what turns them back into `holiday.mp4`.
It joins the parts in order and writes the result straight to your device. Nothing is re-encoded, so the rebuilt file is identical to the one that was split — you can confirm it by checking the file size matches.
What it is not is a video editor. Joining two different recordings end to end at the byte level does not produce a playable video, no matter what the files are called — the second one's header ends up in the middle of the first one's data. Stitching separate clips together is real editing work, and the paid clip stitcher is the tool for it. This page is honest about the difference because getting it wrong wastes your time and produces a file that looks right and does not play.
When You Need to Rejoin Video Parts
Usually because someone sent you a file in pieces. Large footage arrives split when it was too big to email, too big for a chat app, or too big for the portal it came through — and the sender used a splitter to get it under the limit.
It also comes up with archives. Backups written across discs or memory cards are often stored as numbered volumes, and cameras themselves split long recordings automatically once a file hits a size limit imposed by the memory card's format.
And it comes up after using a splitter yourself: you split a file to move it, and now you are at the other end and need it whole again.
Getting the Order Right — the Part That Actually Matters
Order is the only thing a merger can get wrong, and it fails quietly when it does: the joined file is the correct size, opens, plays for a moment, and stops. Nothing about it announces the mistake.
So the order is worked out from the filenames and then shown to you before anything is joined. The common conventions are all recognised — `name.mp4.001`, `name.part01.mp4`, `name_part_2.mp4`, `name-3.mp4` — and numbers are read as numbers, so part 10 comes after part 9 rather than after part 1.
If a part is missing or one appears twice, you are told before you merge rather than after. And if a file was renamed on its way to you and the order looks wrong, every row can be moved up or down by hand. The list is the merge order, exactly as shown.
How It Works: Nothing Leaves Your Device
Each part is read from your own disk and written into the output one after another, in the order on screen. The browser handles the file as a reference rather than loading it into memory, which is why the size of the finished video does not matter — a 30 GB rebuild works the same way a 300 MB one does.
A zip is handled the same way. Rather than unpacking the whole archive, the tool reads its index — a few kilobytes at the end of the file — and takes each part directly out of it. For a zip made by this site's splitter, which stores rather than compresses, that costs nothing at all.
At no point does any of it reach a server.
Is It Really Private?
Yes. The merge happens inside your browser, on your device, and the finished video goes straight to your downloads folder. No part of the file is uploaded, so there is no copy anywhere for anyone to keep, and no account is needed to do it.
That is worth something specific here: footage that arrives split is usually footage that was too large and too private to put through a transfer service in the first place. Rebuilding it on a stranger's server would undo the reason it was split.
As with everything under Imagera's free tools, you can verify the claim rather than take it: load the page, go offline, and merge.
Merging Parts vs Editing Clips Together
Two different jobs, and the right one depends on where your files came from.
Rejoining parts — this free tool — when your files are pieces of one original: numbered, all the same size except the last, and useless on their own. The result is the original file back, exactly.
Stitching clips — the paid Imagera clip stitcher — when your files are separate recordings that each play on their own and you want one video out of them. That needs re-encoding to a common format, and it is where transitions, music and captions live.
If your files are numbered `.001`, `.002`, you are in the right place.