AAC to MKV Converter

Convert AAC to MKV online, for free.



Choose Files
  • From Device
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  • From Url
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Video Options
Choose a codec to encode or compress the video stream. To use the most common codec, select "Auto" (recommended). To convert without re-encoding video, choose "Copy" (not recommended).
Select a resolution for your video (width x height) in pixels.
Change the ratio between width and height, for example, 4:3 or 3:2
Change FPS (frames per second) of video
Video will be rotated clockwise.
Sets the mode of sizing the video. "Max" resizes the video to fit within the width and height, but will not increase the size of the image if it is smaller than width or height. "Crop" resizes the video to fill the width and height dimensions and crops any excess video data. "Scale" enforces the video width and height by scaling. "Pad" resizes the video to the width and height dimensions and keeps the aspect ratio by adding black bars if necessary.
Subtitle Settings
Select the best option for your subtitles: 'Upload' to add your own, or 'Copy' to replicate from the original file.
Choose a file Browse
Upload a .srt or .ass file.
Hardsubs, always visible and integrated into the video, are suitable for permanent captions, while softsubs, stored separately, can be turned on or off for customized viewing.
Audio Options
Choose a codec to encode or compress the audio stream. To use the most common codec, select "Auto" (recommended). To convert without re-encoding audio, choose "Copy" (not recommended).
100% represents the original volume. To double the volume, increase it to 200%. To reduce volume by half, select 50%
Trim Settings
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How to Convert AAC to MKV?

  1. Click the “Choose Files” button to select your AAC files.
  2. Click the “Convert to MKV” button to start the conversion.
  3. When the status change to “Done” click the “Download MKV” button

Easy to Use

Simply upload your AAC files and click the convert button. You can also batch convert AAC to MKV format.

Best Quality

We use both open source and custom software to make sure our conversions are of the highest quality. In most cases, you can fine-tune conversion parameters using “Advanced Settings” (optional, look for the icon).

Free & Secure

Our AAC to MKV Converter is free and works on any web browser. We guarantee file security and privacy. Files are protected with 256-bit SSL encryption and automatically delete after a few hours.


Advanced Audio Coding (AAC) is a digital audio file format that reduces file size via lossy compression. Its primary uses are digital TV, digital radio, and Internet streaming. It is the standard audio format for iOS, YouTube, Nintendo, and Playstation. ISO/IEC designated the AAC codec as an improvement to MP3, due its ability to compress file size more efficiently while providing quality similar to uncompressed audio.

 

How to open an AAC file?

For best results, use VLC media player to open AAC files. Alternatively, AAC also opens by default in iTunes. AAC files are ubiquitous, however, and open in many other programs and software.

 

Additionally, since AAC files often serve as the audio files for video games, they open on most popular gaming consoles, such as Nintendo 3DS and Playstation 4.

 

Developed by: ISO/IEC MPEG Audio Committee

Initial Release: 1997

Useful links:

https://en.wikipedia.org/wiki/Advanced_Audio_Coding

https://www.iso.org/standard/43345.html?browse=tc

Matroska (MKV) is a free, open-source, container standard that can hold an unlimited amount of audiovisual and multimedia files in a single file format. Since it is open source, a user can customize it with open-source software. The name derives from “Matryoshka” dolls, which is a famous type of Russian handicraft that consists of a set of wooden dolls of decreasing size nested one inside another.

 

How to open an MKV file?

The best way to open an MKV file is to use VLC media player. This media player is compatible with all operating systems and platforms. This is important because MKV is not an industry standard, which means that other media players might not support it.

 

Additionally, MKV does not use codecs to compress file size, which means the file can be quite large. Therefore, another option for opening an MKV file is to download the appropriate codecs that are compatible with the selected media player. To accomplish this, download the Combined Community Codec Pack (CCCP) from a trusted site, such as Ninite.

 

Developed by: Matroska

Initial release: 2002

Useful links:

https://en.wikipedia.org/wiki/Matroska

https://www.matroska.org/

FreeConvert.com can convert your files to these related formats:


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