Simplicity SDK Version 2025.12.4 - Release Notes (Nov 4, 2026)#

The primary tool for the Silicon Labs IoT software development ecosystem, combining wireless software development kits (SDKs) and platform into a single, integrated package.

Release Announcement
Release Summary

Release Announcement#

Starting with the 2025.12 release, the Simplicity SDK transitions from GitHub-based monolithic delivery to a modular, Conan-based package model.

To obtain and work with the Simplicity SDK 2025.12, customers must use Silicon Labs Tool (SLT) v1.1.0 or newer, available through:

SLT-CLI (v1.1.0+) – a standalone command-line tool
Simplicity Installer (v1.1.0+) – a graphical installer that integrates SLT-CLI functionality

This update also introduces a new directory structure organized by technology and functional domain, which may affect how SDKs are integrated, consumed, and automated in developer workflows.

Developer Guidance#

CLI development (Headless or CI/CD dev setups)#

Need to update scripts that rely on ‘git clone’ and integrate SLT to manage and automate the SDK delivery.
Any tooling, scripts, or manual workflows that rely on fixed SDK paths may need to be updated accordingly.

GUI development (Simplicity Studio 6)#

No SLT-CLI integration is needed, but note that SDKs are now stored in versioned Conan package directories managed by SLT.
Directory path changes:
- Studio 5 (SDK 2025.6): ~/SimplicityStudio/SDKs/simplicity_sdk
- Studio 6 (SDK 2025.12): ~/.silabs/slt/installs/conan/p/simplxxxxxxxxxxx/p

Resources#

For SDK download and installation instructions, see the SLT-CLI Getting Started Guide or Simplicity Installer Getting Started Guide.
For project migration, refer to the SLC-CLI Project Migration Guide or Simplicity Studio Project Migration Guide.

Note: This Simplicity SDK release will be published on GitHub for reference purposes only, not recommended for development. Development should use the SDK packages delivered via SLT.

Release Summary#

Release Item	Version	Release Date	Key Features	Chip Enablement
Platform	6.0.3	Nov 4, 2026	Platform MCU Automatic PCLK divider selection defaults to datasheet-compliant values. Power Manager adds EM0/EM1 voltage scaling and power savings. Expanded Clock Manager validation and oscillator configuration options. Bootloader Added EM4 GPIO retention during Firmware Upgrade feature for Series-2 devices. Added support for the xG2D device family. Security Added support for the Key Storage Unit (KSU) in the PSA Crypto API. Micrium OS Restricted Micrium OS usage to Series 2 devices. CPC Soft reset capability for future usage. SPI driver maintenance: removed legacy MMLDMA workaround. MVP Math Library None	EFR32FG23L010F128GM40 EFR32FG23L020F128GM40
RAIL Library	3.0.4	Nov 4, 2026	None	No new chips enabled this release.
RAIL SDK	3.0.4	Nov 4, 2026	None	No new chips enabled this release.
USB	1.6.0	Jan 22, 2026	Underlying platform changes only.	No new chips enabled this release.
Wi-Fi 6 + BLE (WiSeConnect)	4.0.3	Jun 11, 2026	Wi-Fi Added Wi-Fi Protected Setup (WPS) Push Button Configuration (PBC) feature support in Station mode. Vendor-specific IE support for Station (STA), SoftAP, and Concurrent Modes. Network Stack Added DHCP support from host for IPv4 in Dual Stack mode. Added SNI extension support for Embedded MQTT. Added NAT/PAT feature support. Added DNS IP address support in AP mode. Added support for Subject Name validation during TLS connections. Added IPv6 support in Dual Stack mode. Added DNS-SD support over mDNS for IPv4 and IPv6. Added adaptive timer optimizations in hosted Network Stack LWIP (IPv6 ND6, DHCP, DNS, ARP, ACD, TCP, and MLD6) for improved power efficiency. SiWx91x Platform Introduced Wakeup-on-Wireless feature. Enhanced driver support for BOD, OPAMP and SSI Peripherals. Added CMake build system support.	No new chips enabled this release.
OpenThread	3.0.3	Nov 4, 2026	OpenThread None Multiprotocol None	OpenThread None Multiprotocol None
Zigbee	9.0 Revision 3	Nov 4, 2026	Zigbee None Multiprotocol None	Zigbee None Multiprotocol None
Bluetooth LE	11.0.3	Nov 4, 2026	Example and Middleware Host examples shown on Studio Launcher page. Most bootloader-aware example applications converted to standalone to simplify early development. Host Stack Bluetooth host qualification for Core specification 6.1. PAwR event counter reporting. Channel classification reporting for a remote peripheral device. Support for larger BGAPI payload size in NCP applications. Controller PAwR event counter reporting. Support for HCI_LE_Set_Resolvable_Private_Address_Timeout (v2). Multiprotocol None	Bluetooth LE Added xGM270S SiP module support. Multiprotocol None
Bluetooth Mesh	10.3.0	Nov 4, 2026	Targeted quality improvements and bug fixes.	No new chips enabled this release.
Bluetooth Location Services	11.0.3	Nov 4, 2026	Support for multiple sub-events per initiator and reflector role in a CS procedure. Support for non-zero maximum procedure count in REAL_TIME_FAST algorithm mode.	No new chips enabled this release.
Z-Wave	8.0.4	Nov 4, 2026	Addressing the increasing demands for low power in battery-operated devices, the Z-Wave stack is now implemented independently from the platform power state (e.g., energy modes: EM0, EM1, EM1P, EM2, EM3/EM4). The Z-Wave Long Range TX output power algorithm is refactored. The 9.6 kbps PHY is used only if an end device in the network is not able to operate at a higher modulation rate (40 kbps or 100 kbps).	No new chips enabled this release.
Wi-SUN	2.11.2	Nov 4, 2026	None	No new chips enabled this release.
Silicon Labs Matter	2.8.1-1.5	Mar 25, 2026	Quality-tested Matter 1.5 solution for Thread and WiFi. Added support for Amazon Matter Simple Setup (MSS) with 917SoC. Added Matter demo for an Oven and Range Hood App. Added further optimizations in LwIP timers.	This release supports Series 2 and Series 3 EFR32 devices. Use v2.2.x-1.2 for Series 1 devices.
Amazon Sidewalk	2.8.4	Nov 4, 2026	Support for RAIL 3.0. Support for Simplicity SDK 2025.12.3.	No new chips enabled this release.
Connect	4.2.4	Nov 4, 2026	None	No new chips enabled this release.
Machine Learning	2.2.3	Nov 4, 2026	None	No new chips enabled this release.
Simplicity Connect Mobile App	3.2.2	May 4, 2026	None	No new chips enabled this release.

Note: Click here for earlier releases on GitHub.
Looking for older release notes? You can still access previous versions for both Simplicity SDK (prior to 2025.6.0) and Gecko SDK here.