Kannel
Kannel is a free, open-source WAP and SMS gateway for self-hosted mobile connectivity and messaging.
What Kannel is
Kannel is a free, open-source WAP and SMS gateway for self-hosted mobile connectivity and messaging. It links HTTP-based services to SMS centers and provides an HTTP interface for administration and sending messages. The gateway handles both mobile-originated and mobile-terminated SMS, with documented connections over HTTP and SMPP. Supported SMS protocols include CIMD 1.3 and 2.0, SMPP 3.4, UCP/EMI 4.0, SEMA SMS2000 OIS, and AT-protocol modems and phones. For WAP, Kannel translates WAP requests into HTTP, compresses WML pages, and supports WAP Push SI and SL. Its guide documents SSL for HTTP client and server communication and SSL-enabled SMPP connections. Kannel is mainly developed on Linux and is described as portable to other Unix-like systems. The download page identifies version 1.4.5 as the stable production release and 1.5.0 as a development release. The project began in June 1999, founded by Wapit Ltd., and directs users to mailing lists for support and development discussion.
Good
- Connects HTTP services with SMS centers
- Supports mobile-originated and mobile-terminated SMS
- Includes WAP translation and WAP Push
- Documents SSL for HTTP and SMPP
- Available as free self-hosted software
Watch out
- SMSC drivers do not share identical features
- Many SMS checklist items are marked not tested
- Stable release is version 1.4.5
- Primarily developed for Linux
Who it suits
It suits operators building self-hosted SMS or WAP gateway infrastructure on Linux and related Unix-like systems. Developers needing HTTP-based messaging integration can use its documented interfaces and protocols.
Verdict
Kannel combines SMS gateway functions, WAP handling, and documented protocol integrations in a self-hosted package. Its driver differences and noted untested capabilities require attention during deployment planning.
Plans and prices
From Kannel's own pricing page, checked 7 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| Kannel | Free | Open-source WAP and SMS gateway · self-hosted |
The facts
Each one read from Kannel's own pages, with the date it was checked.
What it does
- Download
- The download page identifies version 1.4.5 as the stable release intended for production systems and version 1.5.0 as the development release.checked 7 Oct 2026
- Inbound webhooks
- Yeschecked 24 Sep 2026
- Integration
- Kannel provides an HTTP interface for administration and sending SMS, and its guide documents HTTP and SMPP SMSC connections.checked 7 Oct 2026
- License
- The Kannel Software License permits redistribution and modification of source and binary forms subject to its stated conditions.checked 7 Oct 2026
- Messaging
- The user guide describes support for mobile-originated and mobile-terminated SMS messages.checked 7 Oct 2026
- Product
- Kannel is an open-source WAP and SMS gateway for mobile internet connectivity, WAP Push, and SMS messaging.checked 7 Oct 2026
- Project history
- The project site says Wapit Ltd. founded Kannel in June 1999 and that the project is coordinated by members of the Kannel Group.checked 7 Oct 2026
- Security
- The user guide documents SSL support for HTTP client and server communication, and SSL-enabled SMPP connections.checked 7 Oct 2026
- SMSC limits
- The user guide cautions that SMSC drivers do not all support the same features and that many checklist entries are marked not tested.checked 7 Oct 2026
- SMS protocols
- The FAQ lists support for CIMD 1.3 and 2.0, SMPP 3.4, UCP/EMI 4.0, SEMA SMS2000 OIS, and AT-protocol modems and phones.checked 7 Oct 2026
- SMS use
- It links HTTP-based services to SMS centers and provides a unified interface for sending SMS messages.checked 7 Oct 2026
- Support
- The project directs users to its mailing lists for contact information and the developer mailing list for development discussion and patches.checked 7 Oct 2026
- Two-way SMS
- Yeschecked 24 Sep 2026
- WAP features
- The gateway translates WAP requests to HTTP and compresses WML pages for delivery to phones.checked 7 Oct 2026
- WAP Push
- The user guide lists support for WAP Push SI and SL.checked 7 Oct 2026
The company
- Founded
- 1999checked 28 Sep 2026
Money
- Free plan
- Yeschecked 24 Sep 2026
Where it runs
- Platform
- Kannel is mainly developed on Linux and the overview says it should be fairly easy to port to other Unix-like systems.checked 7 Oct 2026
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