GSM to FAP Converter

Encode GSM telephony audio into PARIS FAP format online

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PARIS Workstation Audio

Transform GSM telephony speech into the FAP format — native to Ensoniq PARIS digital audio recording and mixing hardware.

Web-Based Conversion

No Ensoniq tools or PARIS software required. The GSM to FAP conversion runs entirely on our servers.

Secure Processing

Uploaded GSM recordings are deleted immediately. FAP files are purged from servers within 24 hours.

How to convert GSM to FAP

1

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

2

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

3

Let the file convert and you can download your fap 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
FAP is a byte-swapped variant of the PAF (Paris Audio File) format associated with the Ensoniq PARIS digital audio workstation, a recording environment popular among project-studio engineers in the late 1990s. Where standard PAF stores sample data in big-endian order, FAP reverses the byte layout for little-endian architectures, enabling direct memory mapping on Intel-based processors without a runtime byte-swap penalty. The underlying payload is uncompressed linear PCM at up to 24-bit depth and 96 kHz sampling, preserving full studio-grade fidelity. Because there is no lossy coding stage, recordings survive unlimited edit cycles with zero generational loss — a critical property during tracking and mixing. The SoX command-line utility maintains read/write support for FAP, making it the most accessible tool for converting legacy PARIS sessions to modern formats. Despite its niche origins, FAP demonstrates solid engineering: the header is minimal and deterministic, eliminating ambiguity that sometimes plagues chunk-based containers. Advantages include bit-perfect audio preservation, fast I/O on x86 hardware due to native byte order, and straightforward interoperability with raw PCM tools.
Developer: Ensoniq
Initial release: 1998

Frequently Asked Questions

What is FAP?

FAP is the PARIS Audio File format associated with Ensoniq digital audio workstation hardware for recording and mixing.

Why convert GSM to FAP?

FAP conversion is needed when importing speech audio into Ensoniq PARIS workstation projects or compatible audio editing tools.

What software reads FAP files?

PARIS workstation software and SoX can handle FAP files. It is a niche format not supported by most consumer audio players.

Is FAP lossless?

FAP stores audio in a format native to PARIS hardware. The decoded GSM speech is preserved without additional compression.

How is my data handled?

GSM uploads are erased after conversion. FAP outputs are deleted from servers within 24 hours.