1Upload every file you want combined — at least two of them.
2Drag the uploaded items into the order you want; the order is taken from the list, not from the filenames.
3Start the merge, which joins matching inputs without re-encoding them and reconciles mismatched ones exactly once.
4Download the single combined MPEG file.
Merge MPEG FAQ
Is the merge lossless?
+
It is whenever the inputs already agree — the encoded data is copied straight through. It stops being lossless only when the inputs disagree and something has to be re-encoded to make them compatible, and even then it is one pass, not one per file.
How does Merge MPEG join the files together?
+
Concretely, clips with matching codec, resolution and frame rate are concatenated as a stream copy and the join is instant; anything mismatched is normalised to a common format first, which is the slow path but the only correct one. Upload everything you want combined and the result comes back as a single file.
Anything specific to MPEG when merging?
+
Yes — MPEG-1/2 uses a program stream rather than a modern index, so cuts are aligned to GOP boundaries unless the picture is re-encoded. That is worth checking when the inputs did not all come from the same source.
How many files can I combine at once?
+
On the free tier a merge accepts two files at a time, which is deliberately higher than the single-file limit on other tools because merging one file is meaningless. A pass removes the cap entirely.
What can I upload to Merge MPEG?
+
MP4, MOV, MKV, WebM, AVI, WMV, FLV, 3GP, M4V, MPEG and MPG. The container and codec are probed before anything runs, so a mixed batch is handled correctly per file rather than assumed to be uniform.
Is there a file size limit on Merge MPEG?
+
Yes: free accounts process video up to 1 GiB per file, by far the most generous cap on the site; ffmpeg with x264, x265 and libvpx does the work, which is the same toolchain behind most desktop video software. Video is the one family where the cap is high enough that upload time, not the limit, is what you will actually notice.
Will Merge MPEG lower the quality of my MPEG videos?
+
It depends on whether the job needs a re-encode. Operations that only touch the container or the timeline are done as a stream copy and the picture is bit-identical to the source. Anything that has to redraw frames goes through x264/x265 at a quality level you set, where CRF 23 is visually transparent on most footage.
Can I run Merge MPEG on several MPEG videos at once?
+
Yes. Uploads queue in parallel, which matters more here than anywhere else because video jobs are minutes rather than seconds. Free accounts run one file at a time; a pass lifts that.
Why does a EPUB site host Merge MPEG?
+
EPUB.to is built around the open eBook format — XHTML in a zip, reflowable by design, and readable on hardware nobody has thought about the layout for. A book is a zip full of markup, images and fonts, so almost every job people bring to an eBook site is really a job on one of those things. Merge MPEG runs on the same upload and the same account as the conversions because that is where it is needed.
What should I do with the result once Merge MPEG is finished?
+
The converter on this site moves books between EPUB, MOBI, AZW3, PDF and DOCX, so a title ends up on whatever hardware is actually going to read it. Doing that after Merge MPEG means the conversion is made from the version you settled on, not from the one you were still fixing.
Is Merge MPEG here the same tool the sibling sites run?
+
The engines are shared — the same toolchain, the same workers, the same limits. What a EPUB site adds is a view on reflow: which of these operations a reflowable book genuinely supports, and which ones only make sense on the fixed-layout media inside it. It also starts from one fact about the format this site is named after: the book is a zip of XHTML with a manifest, so the text costs almost nothing and every decision that matters is about the embedded images and font subsets.
Do I need an account, and does anything get kept?
+
No account, and nothing is kept: uploads are deleted from the workers shortly after the job finishes, nothing is read and nothing is indexed. Free accounts exist for history and batch size, not for access.
