F4V to MKV converter
Convert F4V to MKV in seconds, free and unlimited. No upload, no sign-up, no watermark: your video never leaves your device.
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Quick answer: To convert F4V to MKV, add the F4V file to the iHateFiles F4V to MKV converter and press Convert. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. F4V is a format most software has stopped opening. MKV is not.
Should you convert F4V to MKV?
Yes. F4V is a format most current software no longer opens, so converting it is the reliable way to keep watching it. MKV is a reasonable target; MP4 is the safest.
The picture is re-encoded
An F4V usually holds H.264 video with AAC sound in a Flash wrapper. This writes H.264 video with AAC sound into the MKV. Both sides are compressed with loss, so this is a second generation: leave the quality at its default or higher, because the encoder is working from F4V artefacts rather than the original.
Where the MKV will play
MKV plays on VLC, Plex, most smart TVs and Android, but not the iPhone Photos app or QuickTime.
F4V and MKV side by side
| F4V | MKV | |
|---|---|---|
| Inside the file | H.264 video with AAC sound in a Flash wrapper | H.264 video with AAC sound |
| Compression | Lossy | Lossy |
| Carries sound | Yes | Yes |
| Plays on | Needs converting first | VLC, Plex, most smart TVs and Android, but not the iPhone Photos app or QuickTime |
| Here | Read only | Read and write |
What usually goes wrong
About the F4V. Renaming .f4v to .mp4 very often just works, because it already is one.
About the MKV. MKV and WEBM share a signature because WEBM is a restricted Matroska, so tools sometimes report one as the other. What matters is the codecs inside.
How to convert F4V to MKV
- Add your F4V file. It is read from your disk and stays there.
- Check the settings. The output format is already set to MKV.
- Press convert and the MKV file is saved back to your device.
Questions
How do I convert F4V to MKV?
Open this page, add your F4V file, and press convert. The file is decoded and re-encoded by your own browser and saved back to your device. Nothing is uploaded.
Is this F4V to MKV converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Will converting to MKV lose quality?
MKV is a lossy format, so some detail is discarded. The quality control on this page decides how much. The default is set high enough that most people cannot see the difference.
Can I convert several F4V files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.