Convert FLV to MKV
Turn your FLV file into an MKV that plays where you need it, right in your browser.
- Free to start
- In your browser
- Up to 1GB
How to convert FLV to MKV
Upload your FLV file
Drag and drop a FLV file to turn into MKV, or click to browse. Anything under 1GB, and nothing is installed.
Confirm MKV as the output
MKV is already selected, so there is nothing to configure. Switch to another format in the panel if FLV needs to go somewhere else.
Convert and download
We convert the FLV on our servers, usually in under a minute. Create a free account to download the MKV, or keep editing it in REQO.
Why convert FLV to MKV?
FLV was built for the Flash player, which browsers dropped for good at the end of 2020. Any FLV you still have is an archive file that needs converting before it can be watched or edited.
The practical problem: No browser has played Flash video since 2020, so FLV is effectively unplayable on the web. Editors and phones will not open it. The old codecs inside look soft next to a modern H.264 encode.
MKV solves that. Keeps multiple audio and subtitle tracks in one file.
Container
Typical codecs
Best for
Plays on
File size
| Feature | FLV | MKV |
|---|---|---|
| Container | Flash Video | Matroska |
| Typical codecs | Sorenson Spark, VP6, H.264 | Almost anything: H.264, HEVC, AV1, VP9 |
| Best for | Nothing new: Flash reached end of life in 2020 | Archiving with multiple audio and subtitle tracks |
| Plays on | Desktop players only, with effort | VLC and desktop players; rarely anywhere else |
| File size | Moderate, heavily dated | Depends entirely on the codec inside |
FLV to MKV questions
Is the FLV to MKV converter free?
Yes. Convert and preview the result for free, then create a free account to download it. There is no per-file charge and no watermark on the MKV itself beyond the free-plan badge.
Do I need to install any software?
No. The conversion runs on our servers and the whole flow happens in your browser, so it works the same on Windows, macOS, Linux, iPhone and Android. Nothing to install at either end. Where FLV plays: Desktop players only, with effort. Where the MKV you get back plays: VLC and desktop players; rarely anywhere else.
Does converting FLV to MKV reduce the quality?
Converting re-encodes the video, so it is not bit-for-bit identical. We encode at a high quality target, which keeps the result visually indistinguishable from the FLV on normal viewing. What changes is the container and the codec. MKV holds: Almost anything: H.264, HEVC, AV1, VP9. Converting the same file back and forth repeatedly will eventually show, so keep your original.
How large a file can I convert?
Anything under 1GB per upload, which is more footage in some formats than others. FLV: Moderate, heavily dated. MKV coming back: Depends entirely on the codec inside. For anything bigger, trim or compress it first, both are free tools here.
Is my file kept private?
Your upload is processed and then held only as long as your project needs it. Nothing is published, indexed or shared unless you create a share link yourself.
Other formats
Everything else you can do here.
Every conversion for a format
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Convert FLV to MKV now
Free, in your browser, and the file stays open in a full video editor afterwards.