MKV to AAC Converter

Convert MKV to AAC Online

Pull the audio track out of an MKV video and save it as a standalone AAC file — useful when you only want the soundtrack, dialogue, or music from a movie, recording, or screen capture. AAC is a lossy format that holds up better than MP3 at the same bitrate, so you keep clean sound at a small file size. Your MKV's video stream is discarded and the audio is re-encoded (or copied, if it is already AAC) into a raw .aac stream.

How to Convert MKV to AAC

1. Upload Your MKV File: Drag and drop your .mkv into the box, or click "Add Files" to browse. You can queue several MKV files and convert them with the same settings.
2. Set the Quality Preset: Under Advanced Options, leave Quality Preset on "Very High (Recommended)" for transparent sound, or switch to Constant Bitrate / Custom Bitrate to pin an exact rate such as 128 or 256 kbps.
3. Trim or Down-mix (Optional): Use Trim to set a Start time and Duration if you only need a clip, or change Audio Channel / Audio Sample Rate to down-mix to mono or match a target device.
4. Convert and Download: Click "Convert" and save your .aac file. No sign-up, no watermark.

MKV to AAC at a Glance

Frequently Asked Questions

Does converting MKV to AAC lose quality?

Some quality loss is unavoidable because AAC is a lossy format, but it is efficient: a 128 kbps AAC track is generally considered transparent (indistinguishable from the source) for most listeners, and the gap versus the original narrows further at 192-256 kbps. If your MKV already contains an AAC audio track, the closest you can get to lossless is to keep the bitrate at or above the source rate. To avoid a second lossy generation entirely, copy the audio into an MKV-to-M4A conversion only when the source is already AAC.

Will my AAC file keep the title, artist, and album art?

No. A raw .aac file is an ADTS elementary stream with no container, so there is nowhere to store tags or cover art — most players will show it as "Unknown." If you need metadata, convert to MKV to M4A instead: M4A wraps the same AAC audio in an MP4 container that supports title, artist, album, and artwork tags.

What's the difference between AAC and MP3 for this conversion?

At the same bitrate, AAC usually sounds cleaner than MP3, especially at lower rates like 96-128 kbps, and AAC files tend to be a touch smaller at matching quality. MP3 still wins on raw compatibility with older hardware and car stereos. If you need a file that plays on virtually anything, use the MKV to MP3 converter; if you want the better quality-to-size ratio for modern devices, AAC is the right pick.

Which devices and apps play raw .aac files?

AAC playback is broad — iPhones, iPads, Macs, Android phones, and apps like VLC and foobar2000 handle .aac fine, and it is the native format behind Apple Music and YouTube audio. The catch is the raw ADTS wrapper: a few older players and some car head units expect AAC inside an .m4a or .mp4 container rather than a bare .aac stream. If a device refuses the file, re-wrap it as M4A.

How big will the AAC file be?

It depends on bitrate and length, not on the size of the original MKV. At a constant 128 kbps, AAC audio is roughly 1 MB per minute; at 256 kbps it is about 2 MB per minute, so a 60-minute recording lands near 58 MB at 128 kbps. In our testing, a 3-minute 1080p MKV music video re-encoded at the "Very High" preset produced a 2.9 MB AAC file — a fraction of the multi-hundred-megabyte source. Files are uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared. The main practical limit on a large MKV is upload time, since movie-length files can run to several gigabytes.