AAC to MKV Converter
Convert AAC to MKV online for free: nothing to install, no watermark, files encrypted in transit and deleted automatically after conversion.
Advanced options
Drag & drop your AAC file here, or
How to convert AAC to MKV in 3 steps
- 1
Upload your AAC file
Drag and drop or select the AAC file you want to convert.
- 2
Choose MKV as output
The output format is pre-selected for you — just confirm and start the conversion.
- 3
Download your file
Once processing finishes, download your converted MKV file instantly.
AAC vs MKV: what is the difference?
| AAC | MKV | |
|---|---|---|
| Full name | Advanced Audio Coding | Matroska Video |
| Type | Compressed audio | Video container |
| Compression | Lossy | Depends on the codec |
| Developed by | MPEG (ISO/IEC) | Matroska.org |
| File extension | .aac | .mkv |
What is AAC?
AAC is the successor to MP3 and generally sounds better at the same bitrate. It is the audio format behind Apple Music, YouTube and most MP4 videos, and it is supported by all modern phones and browsers.
What is MKV?
MKV (Matroska) is an open, royalty-free container that can hold any number of video, audio and subtitle tracks plus chapters in a single file. It is popular for films and archives, but many phones, TVs and editors do not open it natively.
Tips for converting AAC to MKV
- Converting a compressed file such as MP3 to a lossless format does not restore detail already removed; it only makes the file larger.
- For music, a lossless source (WAV or FLAC) gives the best result when you convert to MKV.
- Check that your player, car stereo or editing app supports MKV before converting a whole library.
- Keep the original AAC file as a backup until you are happy with the converted audio.
Frequently asked questions
- How do I convert AAC to MKV online?
- Upload your AAC file above, select MKV as the output format, and click Convert. ConvertFastHub processes the file in the cloud and gives you a download link — no software installation required.
- Is it free to convert AAC to MKV?
- Yes. Free accounts get 10 conversions every 24 hours with files up to 50MB. For unlimited conversions, larger files up to 1.5GB, and priority processing, upgrade to ConvertFastHub Pro.
- Is my file safe when I convert it?
- Files travel over an encrypted connection, are scanned automatically for malware (files up to 200 MB), are processed in an isolated worker and are deleted automatically: after 1 hour without an account, 24 hours with a free account, or 7 days with Pro.
- Can I convert AAC to MKV on my phone?
- Yes. The converter runs in the browser and the work happens on our servers, so it works the same on Android, iPhone, tablets and computers — there is no app to install.
- Do I need an account?
- No. You can convert without signing up; results are then kept for 1 hour. A free account keeps them for 24 hours and shows your conversion history.