Developing with Silicon Labs RAIL#

Silicon Labs RAIL (Radio Abstraction Interface Layer) provides an intuitive and easily-customizable radio interface that is designed to support proprietary or standards-based wireless protocols. RAIL allows customers to adopt the latest RF technology without sacrificing their previous development investment. It also future-proofs the code migration to future EFR32 ICs. The unified radio software API abstracts the significant number of hardware registers and complexity of the lower-level radio block, allowing customers to focus on their proprietary wireless application development instead of mastering device-specific details. RAIL is delivered through the Proprietary Flex SDK component of the Gecko SDK Suite (GSDK).

rail block diagram

Silicon Labs RAIL is the lowest layer for all networking stacks in Silicon Labs GSDK. RAIL supports a diverse set of radio configurations and functionality and is one of the key underlying technologies of Silicon Labs wireless products. The content on these pages is intended for developers who need to control their device's radio interface and performance through their embedded application.

For details about this release: Links to release notes are available on the Gecko SDK page.

For Silicon Labs' proprietary product information: See the product pages on

For background about RAIL: RAIL Fundamentals is a good place to start.

To get started with development: See the Getting Started section to get started working with example applications.

If you are already in development: See the Developer's Guide or the PHY Development section for details or go directly to the API Reference.