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Convert FLV to MKV - Save Your Flash Videos Forever

Transform Flash videos into the versatile MKV format. Play your old videos anywhere.

Step 1: Upload your files

You can also Drag and drop files.

Step 2: Choose format
Step 3: Convert files

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Flash is Dead, But Your Videos Don't Have to Be

Adobe officially ended Flash support in December 2020. If you have FLV files from the Flash era, they're getting harder to play. Many browsers won't touch them, and media players are dropping support.

Converting to MKV gives your Flash videos a future. MKV is an open, widely-supported container that works with virtually every modern media player. Your old videos stay playable for years to come.

How to Convert FLV to MKV

  1. Upload your FLV file - Drag and drop or click to select your Flash video
  2. Confirm MKV output - MKV is selected as your target format
  3. Download your video - Get your converted file ready for any player

The entire process happens in your browser. No software to install, no accounts to create.

Why Convert FLV to MKV?

FLV was designed for streaming over the web using Flash Player. It served its purpose well, but that era is over. Here's why MKV is the better choice now:

  • Universal playback - VLC, Windows Media Player, Kodi, and most media players handle MKV natively
  • Multiple audio tracks - MKV supports multiple audio streams in one file, unlike FLV
  • Subtitle support - Embed subtitles directly in the file
  • Chapter markers - Navigate long videos easily
  • Future-proof - MKV is an open standard with ongoing development

In our testing, MKV files converted from FLV play smoothly on every major platform without requiring special codecs or plugins.

FLV vs MKV: Technical Comparison

Understanding the difference helps you see why this conversion makes sense:

  • Container flexibility - FLV supports limited codecs (Sorenson, VP6, H.264). MKV accepts nearly any video and audio codec
  • Metadata - MKV handles extensive metadata, chapter information, and attachments. FLV has basic tagging only
  • File size - Both are efficient containers. Your converted file will be similar in size to the original
  • Streaming - FLV was built for streaming, MKV is optimized for local playback and archival

The conversion repackages your video without re-encoding when possible, preserving the original quality.

Common Use Cases

Archiving Old Web Videos

Downloaded Flash videos from the 2000s and early 2010s? Convert them to MKV before they become unplayable. Many video sites from that era used FLV exclusively.

Building a Media Library

If you're organizing videos for Plex, Kodi, or similar media servers, MKV is the preferred format. It integrates better with media library software than FLV.

Editing Legacy Footage

Some video editors struggle with FLV files. Converting to MKV first can make editing smoother, especially with older footage.

Alternative Formats to Consider

MKV isn't the only option for your FLV files. Depending on your needs:

  • FLV to MP4 - Better for sharing online or mobile devices. MP4 has wider compatibility on phones and tablets
  • FLV to AVI - Good for older Windows software that doesn't recognize MKV
  • FLV to WEBM - Ideal for embedding videos on websites

Choose MKV when you want maximum flexibility and don't need to worry about mobile compatibility.

Works on Any Device

Our converter runs entirely in your browser:

  • Windows, Mac, Linux, Chromebook
  • Chrome, Firefox, Safari, Edge
  • Tablets and phones (for smaller files)

No plugins, no Flash Player (ironically), no downloads required.

Pro Tip

If your FLV file has multiple audio tracks (rare but possible), MKV will preserve all of them. MP4 typically only keeps one audio track. This makes MKV ideal for multilingual content.

Common Mistake

Assuming all FLV files are low quality. Many FLV files from the mid-2000s onward used H.264 encoding and look fine when converted. Don't discard them without checking.

Best For

Archiving Flash-era video content for long-term storage. MKV's open format ensures your converted videos will remain playable as technology evolves.

Not Recommended

Skip MKV if you primarily watch videos on iPhone or iPad. Apple devices don't natively support MKV. Convert to MP4 for iOS compatibility instead.

Frequently Asked Questions

No. When possible, we remux the video stream without re-encoding, preserving the original quality exactly. The conversion changes the container, not the video itself.

Most smart TVs and streaming devices (Roku, Fire TV, Chromecast) support MKV playback. If yours doesn't, consider converting to MP4 instead for broader TV compatibility.

FLV files required Flash Player, which Adobe discontinued in 2020. Browsers removed Flash support, and many media players have dropped FLV compatibility. Converting to MKV solves this.

FLV is a legacy Flash container with limited codec support. MKV is a modern, open container supporting virtually any codec, multiple audio tracks, subtitles, and chapters.

Yes. Upload several FLV files and convert them all to MKV in a single batch. No need to process each file individually.

MKV offers more features (multiple audio tracks, better subtitle support). MP4 has wider compatibility on mobile devices. Choose MKV for archival and desktop playback, MP4 for mobile sharing.

For most files, conversion takes seconds to a few minutes depending on file size and your device. Remuxing is faster than full re-encoding.

File sizes are typically similar. MKV is an efficient container that doesn't add significant overhead. Some files may be slightly smaller or larger depending on how metadata is stored.

Yes. VLC is one of the best players for MKV files and handles them without any additional codecs. The converted files will play immediately in VLC.

No. The conversion happens entirely in your browser using local processing. Your videos never leave your device during conversion.

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