MKV to AAC converter
Extract AAC audio from MKV video free online. Get compact, high-quality audio from Matroska files. No signup, 500 MB limit, auto-deleted in 1 hour.
Drop a file to convert here
or click to browse
About Advanced Audio Coding
Common Use Cases
- Extracting audio from media library files as compact AAC
- Getting soundtracks from MKV in a space-efficient format
- Creating portable audio from video for Apple devices
MKV files can contain audio in many formats: AAC, AC3, DTS, FLAC, or PCM. Extracting to AAC gives you a compact, high-quality audio file that works on Apple devices, in web browsers, and in most modern media players. If the MKV already contains AAC, the extraction is a lossless stream copy.
MKV bundles video with one or more audio tracks. AAC extraction gives you the audio in a compact lossy format that balances quality and file size, with perfect lossless extraction when the source is already AAC.
Why Convert MKV to AAC?
Lossless when source is AAC
Many MKV files contain AAC audio tracks. When they do, FFmpeg copies the stream directly with zero quality loss.
Compact file size
AAC produces excellent quality at small file sizes. An hour of AAC audio at 192 kbps is roughly 86 MB, compared to 635 MB for uncompressed WAV.
Apple device friendly
AAC is the native audio format for Apple devices, iTunes, and Apple Music. Extracted AAC files sync and play seamlessly.
Better than MP3
AAC is a more efficient codec than MP3. At the same bitrate, AAC sounds noticeably better, especially at lower bitrates.
When to use each
Keep as MKV when...
- Watching with video in a player
- You need surround sound (AC3/DTS)
- Multiple audio tracks matter
- Playing through media center software
- Subtitle tracks are needed
Extract to AAC when...
- You want just the audio, compressed
- Stereo audio for portable listening
- Apple device playback
- Building an audio playlist from video
- Compact file size is the priority
Common use cases
- Extracting audio from media library files as compact AAC
- Getting soundtracks from MKV in a space-efficient format
- Creating portable audio from video for Apple devices
How to use
- Upload your MKV file. Drag and drop your MKV onto the upload area, or click to browse. Uploads are limited to 500 MB per file.
- Start the conversion. Click Convert File and FFmpeg extracts the audio from the MKV. AAC streams are copied directly; other formats are transcoded to AAC.
- Download your AAC file. Download the AAC audio file. It works on Apple devices, in web browsers, and in most media players. Files are auto-deleted within 1 hour.
Frequently asked questions
- Which audio track is extracted?
- The converter extracts the default audio track from the MKV. For files with multiple language tracks, this is typically the primary audio stream.
- Will AC3 or DTS audio convert to AAC?
- Yes. FFmpeg decodes AC3, DTS, and other codecs and transcodes them to AAC. Multi-channel audio is downmixed to stereo.
- Is AAC extraction from MKV lossless?
- Only if the MKV already contains AAC audio. In that case, the stream is copied byte-for-byte. Other codecs require transcoding, which is lossy.
- Why AAC instead of MP3?
- AAC produces better quality than MP3 at the same bitrate. It is also the native format for Apple devices, making it the better choice for most users.
- Is MKV to AAC conversion free?
- Yes. Anonymous visitors get a free daily cap, registered users get a higher limit, and Premium or Lifetime members get unlimited conversions.
- Is there a file size limit?
- Yes, 500 MB per upload.
- What if my MKV has FLAC audio?
- FLAC audio is lossless, so transcoding to AAC produces excellent results. The AAC will be much smaller than the FLAC while maintaining high perceptual quality.