GSM to M4A converter
Convert GSM to M4A in seconds, free and unlimited. No upload, no sign-up, no watermark: your audio never leaves your device.
Last updated
Quick answer: To convert GSM to M4A, add the GSM file to the iHateFiles GSM to M4A converter and press Convert. The conversion runs in your browser, so the file is never uploaded, and it is free with no sign-up, watermark or size limit. GSM is a format most software has stopped opening. M4A is not.
Should you convert GSM to M4A?
Yes. Very little current software opens GSM, so converting it is the way to keep listening to it. Pick a generous bitrate.
Both GSM and M4A are lossy
GSM (GSM full-rate speech) has already discarded some of the sound, and M4A (AAC) will discard a little more. The M4A encoder works from the GSM, not the original recording, so pick a bitrate at or above the source. A lower one saves space and costs quality you cannot get back.
GSM was made for voices
GSM is a phone-call codec that keeps only the frequencies speech needs, roughly up to 4 kHz. Converting to M4A makes the recording open everywhere, but it will still sound like a phone call, because the rest of the sound was never recorded.
Where the M4A will play
M4A plays on Apple devices, Android, browsers and most modern players.
GSM and M4A side by side
| GSM | M4A | |
|---|---|---|
| Inside the file | GSM full-rate speech | AAC |
| Compression | Lossy | Lossy |
| Carries sound | Yes | Yes |
| One minute of stereo | about 0.1 MB | 1 to 1.9 MB |
| Plays on | Needs converting first | Apple devices, Android, browsers and most modern players |
| Here | Read only | Read and write |
What usually goes wrong
About the GSM. The quality ceiling is the codec, not the file. Converting to a higher bitrate cannot add back a frequency range that was never captured.
About the M4A. M4A, M4B, M4R and AAC are largely the same thing with different extensions. Renaming usually works, though it is not something to rely on.
How to convert GSM to M4A
- Add your GSM file. It is read from your disk and stays there.
- Check the settings. The output format is already set to M4A.
- Press convert and the M4A file is saved back to your device.
Questions
How do I convert GSM to M4A?
Open this page, add your GSM file, and press convert. The file is decoded and re-encoded by your own browser and saved back to your device. Nothing is uploaded.
Is this GSM to M4A converter free?
Yes, completely. There is no account, no sign-in, no watermark and no daily limit, because there is no server doing the work. Your own device does it.
Are my files uploaded anywhere?
No. There is no upload endpoint. The conversion runs inside this browser tab, so your file never leaves your device. You can open your browser's network panel and watch: nothing carrying your file is sent.
Is there a file size limit?
No fixed limit. Because the work happens on your machine there is no server quota. The only ceiling is your own device's memory, which for video means very large files may be slow.
Will converting to M4A lose quality?
M4A is a lossy format, so some detail is discarded. The quality control on this page decides how much. The default is set high enough that most people cannot see the difference.
Can I convert several GSM files at once?
Yes. Add as many as you like and they are converted one after another, then offered as a single ZIP.