This tool converts FLV to MKV completely free and without any functional limitations. Since it is based on the browser API, the processing speed is the fastest because all files are processed locally on your device and are not uploaded to our server.
Batch Convert FLV to MKV Online
With this convertor, you can easily convert multiple FLV files to MKV format directly in your browser — completely free. You can also customize the video resolution (width and height) during the conversion.
To access advanced settings, click the Options button in the top right corner. There, you can set the output size for your MKV files.
Additional Settings:
Video Size: Set the width and height for the output MKV file.
Encoding Speed:Controls how fast the video is encoded. Faster speeds may result in larger file sizes.
Video Bitrate:Set between 1–10,000 Kbps to control the video quality and file size.
Frame Rate:Defines the video’s FPS (frames per second). Higher frame rates produce larger files.
Audio Bitrate:Recommended range is 16–320 Kbps.
Cut Video: Trim the video using a start and end time in HH:MM:SS format.
For example, setting 00:00:05 to 00:00:08 will cut a 3-second clip from the video or animation.
Before converting, you can choose a folder on your device where the converted MKV files will be saved. Each FLV file will be automatically saved to your selected folder after it's successfully converted — no manual downloads needed.
Save All: Once all FLV files are converted, click
Save All to instantly save all MKV files to your selected folder.
About FLV files
FLV (Flash Video) is a container format developed by Adobe for delivering video/audio over the internet using Adobe Flash Player. It was widely used for web streaming, online videos, and gaming platforms in the 2000s. Though largely obsolete after Flash's discontinuation, some legacy systems still use FLV files due to their small size and simple structure.
About MKV files
MKV (Matroska Video) is a flexible, open-source multimedia container that stores video, audio, subtitles, and metadata in a single file. It supports advanced features like multiple audio tracks, chapters, and modern video codecs such as H.265/HEVC. Widely used for HD movies, TV shows, and streaming, MKV is compatible with players like VLC. We can also convert MKV files to animated formats such as GIF, WebP, and APNG.
