1Upload the MP4 videos that came out the wrong way round.
2Pick a quarter turn or a half turn, or type an arbitrary angle and choose a colour for the corners it will expose.
3Apply the rotation; the pixels and the orientation flag are reconciled so every viewer agrees on which way is up.
4Download the rotated MP4 file.
Rotate MP4 FAQ
Can I rotate a whole batch in one go?
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Yes. The same rotation is applied across every file you upload, which is the practical fix for a folder of scans or camera output that all came in the wrong way round.
How does Rotate MP4 turn the file?
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Concretely, a rotation flag is written into the container where the target supports one, which needs no re-encode at all; where it does not, the frames are transposed and the stream is re-encoded once. Quarter turns and half turns are the common case and take the cheapest path available for the format.
Anything specific to MP4 I should know?
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Yes — MP4 keeps its index in a moov atom, so a stream-copy edit is near-instant and the result still seeks properly in a browser. It is the kind of thing that explains why a file looks right in one application and wrong in another.
Why does my file look correct on my phone but sideways elsewhere?
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Because the orientation is stored as an EXIF flag rather than in the pixels, and not every viewer honours it. Rotating here normalises the two — the pixels and the flag end up agreeing, so the file looks the same everywhere.
What can I upload to Rotate MP4?
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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 Rotate MP4?
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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 Rotate MP4 lower the quality of my MP4 videos?
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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 Rotate MP4 on several MP4 videos at once?
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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 Rotate MP4?
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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. Rotate MP4 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 Rotate MP4 is finished?
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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 Rotate MP4 means the conversion is made from the version you settled on, not from the one you were still fixing.
Is Rotate MP4 here the same tool the sibling sites run?
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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?
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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.
