M4A to MKV Converter
Convert M4A audio files (AAC in MPEG-4 container) to MKV (Matroska) container format for versatile multimedia projects. Audio stream is copied without quality loss. Professional-quality audio conversion powered by FFmpeg, all processing happens securely in your browser.
Recommended Settings
For Multimedia
- •Original AAC audio preserved
- •Supports chapters and metadata
- •Versatile container format
For Archiving
- •No quality loss (stream copy)
- •Multiple track support
- •Open-source format
Pro Tips
- •Audio stream is copied without re-encoding (no quality loss)
- •MKV supports chapters, metadata, and cover art
- •Excellent for multimedia projects and archiving
Most Popular
Audio stream copied directly to versatile MKV container
When to Use This Tool
MKV is a flexible multimedia container that can store M4A audio (AAC) with enhanced metadata support.
Recommended: Stream Copy
Store M4A audio in MKV containers for versatile multimedia projects with chapters and metadata.
Recommended: Stream Copy
MKV supports multiple audio tracks, subtitles, and chapters in a single file with AAC audio.
Recommended: Stream Copy
How It Works
Upload your M4A audio file
FFmpeg copies AAC stream to MKV container
Download your MKV file with original audio
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by FFmpeg.wasm (WebAssembly) for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
What is M4A format?
M4A is a file extension for MPEG-4 audio files that typically contains AAC-encoded audio in an MPEG-4 container. It's the standard audio format for iTunes and Apple Music.
Why convert M4A to MKV?
Converting M4A to MKV allows you to store AAC audio in a versatile Matroska container that supports chapters, metadata, cover art, and multiple audio tracks. The audio stream is copied without re-encoding, preserving original quality.
Will I lose quality converting from M4A to MKV?
No, the audio stream is copied directly without re-encoding (using -c:a copy). The AAC audio remains identical - it's just wrapped in an MKV container instead of MPEG-4. There's no quality loss whatsoever.
What's the difference between M4A and AAC in MKV?
The audio data is identical AAC. MKV is just a different container format that provides additional features like chapters, multiple audio tracks, and better metadata support compared to the MPEG-4 container used by M4A.
What players support MKV files?
VLC, MPC-HC, Plex, Kodi, and most modern media players support MKV files with AAC audio. MKV has excellent software support across all platforms.