Free online MKA to GSM converter

Source format

MKA is an audio-only Matroska container. It is commonly used to store music, voice recordings, and multi-track audio with modern codecs such as FLAC, AAC, Opus, or Vorbis. MKA files are popular among users who want flexible metadata support, multiple audio streams, and good compression in a single file.

Target format

GSM is a speech-oriented audio format based on the GSM 06.10 codec. It was designed for telephony and low-bandwidth voice transmission, so it produces very small files but with limited fidelity. GSM is mainly used for voice prompts, legacy phone systems, and other applications where compact speech audio matters more than sound quality.

How to perform the conversion

The most reliable way to convert MKA to GSM is with FFmpeg, because it can read Matroska audio and encode directly to GSM.

1. Install FFmpeg on your computer.
2. Open a terminal or command prompt in the folder containing your MKA file.
3. Run a command like ffmpeg -i input.mka -ac 1 -ar 8000 output.gsm.
4. If the source contains multiple audio tracks, choose the correct one with -map, for example ffmpeg -i input.mka -map 0:a:0 -ac 1 -ar 8000 output.gsm.
5. Check the result by playing the GSM file in a compatible audio player or importing it into your target system.

If you prefer a graphical workflow, you can also use desktop audio tools that support FFmpeg-based export or conversion. On 101convert.com, you can convert the file online for free without installing any software.

Notes on quality and compatibility

GSM is a major quality downgrade from most MKA sources, especially if the MKA file contains music, stereo audio, or high-resolution audio. GSM is optimized for narrowband speech, so it typically uses 8 kHz mono audio and sounds thin or robotic on non-voice material. For best results, convert only speech content, and expect loss of detail, stereo separation, and high frequencies.

Compatibility can also be limited: many modern players support GSM through FFmpeg or system codecs, but some software may not open .gsm files directly. If your destination system requires a specific container or filename extension, verify its requirements before converting. When the source MKA contains subtitles, chapters, or multiple tracks, those elements will not carry over to GSM because GSM is an audio codec format, not a multimedia container.