Step 1: Drop your MP4 files using the button above or by deposit and leave.
Step 2: Click the 'Convert' button to start the conversion.
Step 3: Receive your converted FLV files.
MP4 to FLV Conversion FAQ
How do I convert an MP4 file to FLV?
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Upload your MP4 file using the picker above and the converter detects the source type and runs the MP4 → FLV pipeline. The result downloads automatically when conversion completes; no account needed for one-off conversions.
What happens to the subtitle tracks in my MP4 file?
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They cannot stay selectable, because FLV has no soft-subtitle stream to hold them. There are two ways out: burn them into the video during conversion, which makes them permanent and unstyleable, or export them as a separate .srt alongside the FLV for the player to load. The converter tells you which it did rather than dropping them silently. No current browser, phone or TV can play FLV — anything still in this container has to be moved out of it to remain watchable.
Can I still embed the file on a web page after converting MP4 to FLV?
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Not directly. MP4 plays inline in every browser; FLV does not, so a page embedding it falls back to a download link or an empty player frame. If the file is destined for a website, keep the MP4 for the web and treat the FLV as the archive or editing copy.
Will the FLV still play smoothly on a phone or a TV?
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It may not. MP4 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, MP4 is the safer container to stay in.
What happens to 5.1 surround audio when converting MP4 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 MP4 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 the MP4 to FLV converter free?
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Yes — basic MP4 → FLV conversion is free with no registration. Premium adds higher per-file size limits, more parallel batch workers, and removes ads.
How big an MP4 file can I convert to FLV?
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Free accounts: up to 100 MB per MP4 file. Premium: typically 1 GB per file, depending on the MP4 source type. Very large files are split into chunks server-side when the FLV format allows.
Will conversion change the content of my MP4?
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Conversion preserves all information that both MP4 and FLV can represent. Format-specific features that the FLV format doesn't support (e.g. vector data in raster output, formulas in plain-text output) are rasterized or stripped — see the format-specific notes on the result page.
Can I convert many MP4 files to FLV at once?
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Yes — drop multiple MP4 files into the upload zone and they are queued in parallel. Premium has more parallel workers; on a 50-file batch this is the difference between minutes and seconds.
Does the MP4 to FLV converter work on phones and tablets?
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Yes — the UI is responsive and the conversion pipeline runs server-side, so mobile devices upload-then-download just like desktops. iOS and Android browser file pickers (camera roll, Files app) work end-to-end.
Which browsers does the MP4 to FLV converter support?
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Chrome, Firefox, Safari (15+), Edge, and Opera. The converter uses standard `<input type="file">` upload — no WebAssembly or PWA dependencies — so even older browsers work.
