GSM to ALAC Converter
Processing entirely on your device — large files may take a moment.
GSM 06.10 Speech and Apple Lossless exist for different jobs: GSM 06.10 is the 1990s mobile-telephony speech codec — 13 kbit/s audio that VoIP systems and old answering machines still emit. Convert ALAC to FLAC for non-Apple players, or MP3 for sharing.
This converter runs entirely in your browser using WebAssembly — your files never leave your device, nothing is uploaded, and there are no watermarks, sign-ups or queues. Drop in several files at once to convert them as a batch.
How GSM compares to ALAC
| GSM | ALAC | |
|---|---|---|
| Structure | Raw GSM frames (33 bytes/20ms) | MP4 (alac sample entry) container |
| Types / schema | Lossy speech codec (RPE-LTP) | Lossless, 16-32-bit |
| Compatibility | Asterisk, SoX, ffmpeg | iOS, macOS, iTunes, ffmpeg |
| Best for | Telephony recordings | Apple-ecosystem lossless libraries |
How to convert GSM to ALAC
- 1
Select your files
Drag & drop your GSM files onto the area above, or click to browse. You can add multiple files at once for batch conversion.
- 2
Convert instantly
Click "Convert to ALAC". The conversion runs entirely inside your browser using WebAssembly — no upload, no queue, no waiting.
- 3
Download results
Download each converted ALAC file individually, or grab everything at once as a ZIP archive.
About the GSM format
GSM 06.10 is the speech codec of the original GSM mobile network — 13 kbit/s RPE-LTP that made digital cellphone calls possible in 1991 and still lives inside VoIP systems, old answering machines and Asterisk PBX recordings.
It is lossy speech, not music: converting GSM to WAV or MP3 preserves intelligibility perfectly while finally letting desktop players open the file without special codecs.
+ Strengths
- ✓Tiny bitrate for speech intelligibility
- ✓Ubiquitous in telephony systems
- ✓Decodes natively via ffmpeg
! Limitations
- −Speech-only quality — music falls apart
- −13 kbit/s artifacts are audible
- −8000 Hz sample rate only
About the ALAC format
ALAC (Apple Lossless Audio Codec) is Apple's FLAC equivalent: bit-exact lossless compression inside an MP4 container, opened-source in 2011 and now native on every Apple device and most server-side pipelines. It is what iTunes Store sells as "lossless" and what iPhone recordings encode to by default.
For non-Apple players FLAC is the safer target, and conversion is sample-exact in both directions — the decode is handled by ffmpeg's native ALAC decoder without any Apple runtime.
+ Strengths
- ✓Native on every Apple device
- ✓Open source since 2011
- ✓Reasonable sizes inside MP4
! Limitations
- −Outside Apple ecosystems FLAC wins
- −Slightly worse ratios than FLAC
- −Confusing .m4a extension doubles as lossy
Why convert GSM to ALAC?
Converting makes sense where the strengths of ALAC meet what GSM cannot give you. Native on every Apple device Meanwhile Speech-only quality — music falls apart One pass through the converter above puts your file on the right side of that trade-off.
Frequently asked questions
Is this GSM to ALAC converter really free?
Yes — completely free, with no sign-up, no watermark and no daily conversion limits. The site is supported by advertising.
Are my files uploaded to a server?
No. The conversion runs entirely inside your browser using WebAssembly, so your files never leave your device — that is what makes it instant and private.
Does it work on Windows, Mac, iPhone and Android?
Yes. Anything with a modern browser works: Windows, macOS, Linux, Android and iOS. No software installation is required.
Is there a file size limit for GSM to ALAC?
The only limit is your device's memory, since nothing is uploaded. Files up to a few hundred megabytes work fine on a modern desktop browser; very large files simply take a little longer.
Will converting GSM to ALAC reduce audio quality?
If ALAC is lossless, the output contains everything the GSM file contains — no further loss is added. If ALAC is lossy, one recompression pass is unavoidable; the quality slider controls how much. Loss that already happened in the source file can never be undone by converting.
Are tags like title and artist preserved?
Tag handling varies between target formats and this conversion focuses on the audio itself. For archival copies where tags matter, keep the original file; the converted copy is for playback and sharing.