Convert FLV to MKV

Transform your legacy adobe flash video format into MKV format. Free, private, and browser-based.

How it works

  1. Upload FLV Files — Drag and drop your FLV files into the converter, or click to browse. Common sources: old website archives, legacy flash content.
  2. Convert to MKV — The converter processes your files to MKV format entirely in your browser. No files are uploaded to any server — your privacy is guaranteed.
  3. Download Results — Download your converted MKV files instantly. For multiple files, download individually or as a ZIP archive.

Why convert FLV to MKV

  • Convert to lossless MKV format to prevent further quality degradation during editing
  • Leverage MKV advantages: supports multiple audio/subtitle tracks
  • Overcome FLV limitations: flash is discontinued and no longer supported
  • Upload to websites and platforms that require or prefer MKV format

FAQ

Is FLV to MKV conversion free?
Yes, Fileza.io converts FLV to MKV completely free with no limits on file size or number of conversions. No hidden fees, no watermarks, and no account required.

Will I lose quality converting FLV to MKV?
Both FLV and MKV use lossy compression. Output quality is excellent at high quality settings (85%+) — most people cannot see any difference.

Is it safe to convert FLV to MKV online?
Absolutely. Unlike most online converters, Fileza.io processes your files entirely in your browser using WebAssembly. Your FLV files are never uploaded to any server — the conversion runs on your own device, keeping your files 100% private.

Can I convert multiple FLV files to MKV at once?
Yes, Fileza.io supports batch conversion. Drag and drop multiple FLV files at once and they will all be converted to MKV simultaneously. Download them individually or as a ZIP archive.

Does FLV to MKV conversion work on mobile?
Yes, the converter works on any device with a modern web browser — iPhones, iPads, Android phones, and tablets. No app installation required.

Will the converted MKV files be smaller or larger than FLV?
File sizes depend on content and quality settings. FLV files are typically small, while MKV files are varies by codec.

How long does FLV to MKV conversion take?
Most conversions complete in seconds. The exact time depends on file size and your device performance. Since processing happens locally in your browser, faster devices convert more quickly. Video files may take longer due to re-encoding.