MP4 to SLN Converter
Extract Asterisk PBX audio from MP4 in SLN format
Asterisk PBX Native
SLN is the standard audio format for Asterisk systems. Converting MP4 audio to SLN creates prompts your PBX can load directly.
Prompt Library Builder
Batch convert MP4 videos to SLN and build your complete IVR prompt library in one session — efficient PBX content creation.
Cloud Processing
No Asterisk installation needed for the conversion. Our servers extract and format the SLN audio from your MP4.
How to convert MP4 to SLN
Select files from Computer, Google Drive, Dropbox, URL or by dragging it on the page.
Choose sln or any other format you need as a result (more than 200 formats supported)
Let the file convert and you can download your sln file right afterwards
About formats
Frequently Asked Questions
SLN is Asterisk PBX's native audio format for IVR prompts, voicemail greetings, and hold music. Converting creates audio your PBX system can use directly.
Asterisk, FreePBX, and other Asterisk-based PBX systems load SLN files natively for voice prompts and automated responses.
Standard Asterisk uses 8000 Hz (sln) for narrowband and 16000 Hz (sln16) for wideband. Choose based on your PBX configuration.
Upload several MP4 files and create multiple SLN voice prompts at once — build your entire PBX prompt library in a single session.
Yes — SLN is headerless signed 16-bit linear PCM. Asterisk knows the format based on the file extension and configured sample rate.
Yes — only the audio track from your MP4 is kept. The result is a raw signed linear audio file for PBX use.