1Upload every file you want combined — at least two of them.
2Add the files in the order you want them joined; the first file you add comes first.
3Start the merge; the files are joined one after another into a single file.
4Download the single combined FLV file.
Merge FLV FAQ
Does it matter if the inputs are different formats?
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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. Matching inputs take a fast, lossless path; mismatched ones have to be reconciled to a common format, which is slower and costs one encode.
Anything specific to FLV when merging?
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Yes — nothing plays FLV natively any more, so the practical end of any FLV job is a modern container. That is worth checking when the inputs did not all come from the same source.
How does Merge FLV join the files together?
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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.
Can I run Merge FLV on several FLV 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.
Is there a file size limit on Merge FLV?
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Yes: free accounts process video up to 40 MB 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.
Why does a Word site host Merge FLV?
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WORD.to is built around the editable end of a document's life — the DOCX that is still being written, still being styled and still being argued over, before anyone flattens it for sending. Office files are containers full of other people's media — images, embedded audio, fonts — so the work people need on them is usually the work they would need on those contents anyway. Merge FLV shares the upload, the caps and the account with the conversions for that reason.
What should I do with the result once Merge FLV is finished?
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The converter on this site takes documents out to PDF for sending, to images for embedding and to plain text for anything that has to read them programmatically, and back the other way. Doing that afterwards keeps the editable original around, which is the part you cannot get back once it has been flattened.
Is Merge FLV here the same tool the sibling sites run?
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The engines are shared — the same document toolchain, the same workers, the same limits. What a Word site adds is a view on what survives leaving the Office format and what does not, which is the question every one of these jobs actually turns on. It also starts from one fact about the format this site is named after: the document is a zip of XML, so text edits are cheap and the weight is almost always the embedded images.
Do I need an account, and does anything get kept?
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No account is needed. Uploads and results are kept for about 24 hours, which leaves time to download the result, and are then deleted automatically; nobody reads, lists or indexes them. Several files in one job need a paid plan.
