Convert MKV to FLV Online Free
Convert Matroska MKV video files to FLV for Flash-compatible players and legacy streaming platforms. ChangeThisFile uses FFmpeg on secure servers — no installation or signup needed.
ChangeThisFile converts MKV to FLV free using FFmpeg on secure servers. Upload your Matroska file with encrypted transfer, get your FLV download, and the file is automatically deleted. No signup or software needed — fast, free, and private.
Convert Matroska to FLV
Drop your Matroska file here to convert it instantly
Drag & drop your .mkv file here, or click to browse
Convert to FLV instantly
Matroska vs FLV: Format Comparison
Key differences between the two formats
| Feature | MKV (Matroska) | FLV |
|---|---|---|
| Full Name | Matroska Video | Flash Video |
| Developer | Matroska.org | Adobe Systems |
| Open Standard | Yes | No (proprietary) |
| Video Codec | H.264, H.265, VP9, AV1, MPEG-4 | H.263, VP6, H.264 |
| Audio Codec | AAC, FLAC, AC-3, MP3, Vorbis | MP3, AAC, Nellymoser |
| Subtitle Tracks | Multiple formats supported | Not natively supported |
| Browser Support | Via HTML5 with plugin | Requires Flash Player |
| Streaming | HTTP, HLS, DASH | RTMP |
When to Convert
Common scenarios where this conversion is useful
Flash Platform Submissions
Convert MKV content for upload to legacy Flash-based video platforms, portals, or CMS systems that require FLV input format.
RTMP Streaming Archives
Prepare MKV media files as FLV for ingestion into RTMP-based streaming servers and legacy broadcast workflows.
Consistent Legacy Format Libraries
Convert MKV files to FLV to maintain a uniform format across existing Flash-era video archives and libraries.
Older Embedded Video Players
Supply FLV content for Flash-based video players embedded in legacy websites or enterprise intranets.
E-Learning Flash Platforms
Convert MKV training videos to FLV for upload to e-learning systems built on Adobe Flash-based video delivery.
How to Convert Matroska to FLV
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1
Upload Your MKV File
Click or drag to upload your Matroska MKV file. The upload is secured with HTTPS encryption to protect your content in transit.
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2
FFmpeg Converts to FLV
Our servers use FFmpeg to encode your MKV content into an FLV container with H.264 video and AAC audio for Flash-compatible playback.
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3
Download Your FLV
Download the finished FLV when conversion completes. Your original MKV file is permanently deleted from our servers immediately after.
Frequently Asked Questions
FLV is required for legacy Flash-based video platforms, RTMP streaming servers, and older video players that predate H.264 MP4 support. While Flash is deprecated, FLV archives and some platforms still require this format.
Yes. VLC, MPC-HC, and other modern media players support FLV playback without requiring Flash Player. Flash Player itself was discontinued by Adobe in 2020.
No. FLV does not support embedded subtitle tracks. You will need to burn subtitles into the video or manage them as separate files.
Only the primary audio track is converted to the FLV container. Multiple audio tracks in MKV are not supported in FLV format.
Both your uploaded MKV and the converted FLV are deleted from our servers automatically after your download completes.
Files up to 50MB are supported. For larger MKV files, compress or trim the video beforehand.
Yes, FLV with H.264 encoding supports 720p and 1080p HD resolutions. The output maintains your source MKV resolution.
Yes, completely free. ChangeThisFile requires no payment, no account, and adds no watermarks.
The converted FLV uses H.264 video encoding with AAC audio, providing the best quality-to-size ratio for Flash-compatible delivery.
Only the primary video track is processed. MKV's multiple-track capability is not carried over to the FLV container.
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