Free online WMA to GSM converter

Source format: WMA

WMA stands for Windows Media Audio, an audio format developed by Microsoft. It is commonly used on Windows systems and in older media libraries, especially for music, voice recordings, and compressed audio distribution. WMA files may be either lossy or lossless, depending on the variant, and they are often chosen for relatively small file sizes and decent playback quality.

Target format: GSM

GSM is a narrowband speech audio format originally designed for telephony and voice transmission. It is optimized for speech rather than music, so it produces very small files but with limited audio fidelity. GSM is typically used in voice mail systems, telephony applications, and other low-bandwidth voice workflows where compact size matters more than high-quality sound.

How to perform the conversion

The most reliable way to convert WMA to GSM is with FFmpeg, which supports both formats and gives you control over audio parameters.

1. Install FFmpeg on your computer if it is not already available.
2. Open a terminal or command prompt in the folder containing your WMA file.
3. Run a conversion command such as ffmpeg -i input.wma -ac 1 -ar 8000 -c:a gsm output.gsm.
4. Check the resulting file in a player or in your target application to confirm it plays correctly.

If you prefer a graphical workflow, you can also use desktop audio tools that support export or transcoding through FFmpeg, but FFmpeg is usually the best choice for this specific conversion because GSM requires speech-oriented settings.

You can also convert the file on 101convert.com for free, without installing any software.

Notes on quality and compatibility

WMA to GSM is a major quality reduction. WMA may contain full-band music or higher-quality audio, while GSM is intended for narrowband voice. As a result, music, stereo effects, and high frequencies will be lost or heavily degraded.

For best results, convert speech recordings rather than music. Using mono audio and an 8000 Hz sample rate is typical for GSM and improves compatibility with telephony systems. Some players and editors may not support GSM playback directly, so test the output in the software or device that will use it.

If your goal is general audio sharing rather than telephony, a different target format such as MP3 or WAV may be more appropriate.