GSM to SND Converter

Transform GSM telephony speech into MS-DOS SND format

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DOS-Era Compatibility

Move GSM telephony audio into the SND format — a simple MS-DOS sound type for legacy computing and vintage system preservation.

No Tools Required

Convert GSM to SND directly in your browser. No DOS utilities or command-line software needed on your machine.

Instant Results

Both formats are tiny. Your GSM to SND conversion finishes in moments, ready for immediate use.

How to convert GSM to SND

1

Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.

2

Choose snd or any other format you need as a result (more than 200 formats supported)

3

Let the file convert and you can download your snd file right afterwards

About formats

GSM 06.10 (Full Rate) is the foundational speech codec of the Global System for Mobile Communications standard, ratified by ETSI in 1991 and deployed across hundreds of cellular networks worldwide. Operating at a fixed 13 kbit/s, the algorithm applies Regular Pulse Excitation with Long-Term Prediction (RPE-LTP) to compress 20 ms frames of 8 kHz mono speech into just 33 bytes each. This approach models the vocal tract as a linear predictive filter, encodes the excitation signal, and leverages pitch periodicity for further reduction — tuned to deliver intelligible voice under the bandwidth constraints of early digital mobile channels. The codec powers not only GSM telephony but also many VoIP applications, voicemail systems, and IVR platforms that benefit from its low bitrate. Three concrete advantages stand out. First, extraordinary compression: one minute of speech fits in roughly 100 KB, enabling efficient storage and transmission. Second, universal tooling — libraries such as libgsm and SoX handle encoding and decoding on every major platform. Third, a royalty-free patent landscape that has encouraged adoption across open-source telephony projects like Asterisk and FreeSWITCH.
Initial release: 1991
SND is a multi-platform audio file extension used across several computing ecosystems since the late 1980s. On Sun and NeXT workstations, .snd files follow the AU format structure — a header with magic number 0x2e736e64, data offset, encoding type, sample rate, and channel count, followed by raw audio. On MS-DOS PCs, the same .snd extension was used by early sound utilities like Sounder and SoundTool for simple 8-bit unsigned PCM recordings. Macintosh systems also employed .snd for sound resources embedded in the resource fork. Because the extension is shared across incompatible formats, audio processing tools typically inspect the file header to determine which variant they are handling: files beginning with the AU magic number are treated as Sun/NeXT audio, while headerless files are interpreted as raw PCM with assumed parameters. The Sun/NeXT variant supports multiple encodings including mu-law, A-law, 8-bit and 16-bit linear PCM, and ADPCM, making it versatile for both speech and general audio. One advantage of the AU-style SND is its self-describing header, which enables any compliant player to determine sample format and rate without external metadata. The MS-DOS SND variants hold historical value as artifacts of the era when Sound Blaster cards first brought digital audio to personal computers. SND files from all platforms can be processed and converted using SoX and other audio tools.
Initial release: 1988

Frequently Asked Questions

Why convert GSM to SND?

SND is a legacy MS-DOS sound format. It is useful for running audio on vintage DOS systems or preserving recordings in period-correct format.

What software plays SND files?

SoX, DOSBox, and some vintage audio utilities can play SND files. Modern players may need SoX for conversion to a playable format.

Is SND still used?

SND is a historical format mainly used in retro computing, DOS game preservation, and legacy system maintenance.

How does the quality compare?

SND is a simple 8-bit format. The conversion preserves GSM audio quality within those technical limitations.

Are my recordings handled securely?

GSM uploads are deleted immediately. SND outputs are removed from our servers within 24 hours.