Step 1: Supply your M4V files using the button above or by haul and lay.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Get your converted FLV files.
M4V to FLV Conversion FAQ
Will resolution and frame rate be preserved in the FLV?
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Yes. M4V → FLV keeps resolution, frame rate, and aspect ratio unchanged by default. To change them, use the Resize or Speed tool on the result.
Is the M4V to FLV conversion reversible?
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You can convert the FLV back to M4V on this site. If either format involved is lossy, the round-trip is not bit-perfect even though it is visually or audibly close.
What happens to the subtitle tracks in my M4V file?
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They are dropped. FLV has no soft-subtitle stream to hold them, and the converter neither burns them into the picture nor exports them as a separate file. If you need them, extract the subtitles to an .srt file with a desktop tool such as ffmpeg or MKVToolNix before converting, and load that file alongside the FLV in your player. No current browser, phone or TV can play FLV — anything still in this container has to be moved out of it to remain watchable.
My M4V has several audio tracks — do they all survive into the FLV?
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No. The converter keeps one audio track, the one with the most channels (normally the main mix), and drops the rest; there is no setting to pick a different one. To keep another track, remux the M4V with that track first (VLC or ffmpeg can do this), then convert it. M4V keeps chapter markers, artwork and subtitle tracks in the shape the Apple TV app expects, which plain MP4 often loses.
Why does my M4V file fail to convert to FLV?
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Almost always DRM. Some M4V files are encrypted at the bitstream level by the store or software that issued them, and an encrypted stream cannot be decoded by us or by anything else without the licence key. Files you recorded, exported or downloaded unprotected convert normally; a licensed purchase will not, and no converter can honestly promise otherwise. DRM-protected M4V purchases cannot be converted by anything; only unprotected M4V files are convertible, and non-Apple players often need the extension renamed.
Will the FLV still play smoothly on a phone or a TV?
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It may not. M4V is decoded by dedicated silicon on phones, tablets and TVs, which is why it plays without flattening the battery. FLV typically falls back to software decoding on the same hardware — higher CPU load, a warmer device, and dropped frames on 4K material. For a device target, M4V is the safer container to stay in.
What happens to 5.1 surround audio when converting M4V to FLV?
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It is downmixed to stereo, because FLV has no dependable multichannel path. The fold-down uses the standard ITU coefficients so dialogue in the centre channel stays intelligible and the surrounds come in at reduced level rather than vanishing. Anything that relied on discrete channel placement is gone after that.
Why would I convert M4V to an older format like FLV?
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Because a lot of hardware never learned anything newer and never will. DVD players, in-car head units, camcorder playback modes, industrial displays and plenty of broadcast ingest equipment accept FLV and nothing else. The conversion is a deliberate step down in efficiency, bought in exchange for working on a device that has no other option. FLV’s low per-packet overhead made it excellent at streaming over the unreliable connections of its era, and huge archives of it still exist.
Is there a file-size limit when converting M4V to FLV?
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Free conversions have a size limit per file, set by the type of file, and the page tells you when a file is over it. A paid plan removes that limit, so much larger files can be converted.
Can I batch-convert several M4V files to FLV at once?
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Several files in one job need a paid plan. Free use is one file per conversion, one conversion an hour. On a paid plan you can add several files to one job, then download each result on its own or all of them in one ZIP.
What happens to my M4V files after the conversion?
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Uploaded files are processed on our own conversion servers, nobody looks at them, and they are not shared. The upload and the converted file are both deleted automatically about 24 hours after the conversion, which leaves time to download the result. See /privacy/ for the full policy.
Will my FLV play on phones, tablets, and TVs?
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FLV plays in most desktop players but is sometimes unsupported on mobile and TV. For broadest reach, consider MP4 instead.