1Upload the FLV 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 FLV file.
Rotate FLV FAQ
Does the format decide whether rotation is lossless?
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It does. FLV is the retired Flash container — nothing plays it natively any more, which is normally the reason it is being converted. That property is exactly what determines whether a quarter turn is free or costs a re-encode.
Anything specific to FLV I should know?
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Yes — nothing plays FLV natively any more, so the practical end of any FLV job is a modern container. It is the kind of thing that explains why a file looks right in one application and wrong in another.
How does Rotate FLV 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.
Can I rotate by an arbitrary angle, not just 90 degrees?
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Yes, though the two are different operations underneath. A multiple of 90 degrees rearranges existing data; any other angle has to rebuild the grid and fill the corners, so it costs a resample and usually wants a background colour choosing.
What happens to audio, subtitle and chapter tracks?
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They are carried across. Multi-track audio, embedded subtitle tracks and chapter markers survive wherever the target container can represent them — that is the main thing that separates a proper job from a naive re-encode that silently keeps only track one.
What can I upload to Rotate FLV?
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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 FLV?
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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 FLV lower the quality of my FLV 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.
Why would a modern-format site run Rotate FLV?
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WEBP.to is built around the modern replacement for both of the old defaults: one format that does lossy, lossless, alpha and animation, and reliably lands smaller than the JPEG or PNG it came from. People arrive here having decided the old defaults are costing them bandwidth, and that decision immediately raises the rest: what size, what quality, what happens to the transparency. Rotate FLV is on the same upload and the same account so those questions get answered in one place.
Once Rotate FLV has run, what is worth doing next?
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The converter on this site moves images to and from WebP, PNG, JPG and AVIF, which is where you decide whether a smaller file is worth losing the older browsers. Doing it in that order matters: pick the pixels first and the container afterwards, because the container is the cheap decision and the pixels are the expensive one.
Do the sibling sites run something different?
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The engines are identical — same libraries, same workers, same caps. What is different is the opinion attached, and the opinion here rests on a property of the format this site is named after: the same .webp extension can hold a lossy VP8 frame, a lossless one, or an animation, so the sensible processing path is decided per file rather than per extension.
What happens to my file, and is an account required?
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No account, and nothing is retained: uploads are deleted from the workers shortly after the job finishes, and nothing is inspected, listed or indexed. Accounts exist for history and batch size only.
