---
id: intro
title: Introduction to ZMK
sidebar_label: Introduction
---

ZMK Firmware is an open source (MIT) keyboard
firmware built on the [Zephyr™ Project](https://zephyrproject.org/) Real Time Operating System (RTOS). ZMK's goal is to provide a modern, wireless, and powerful firmware free of licensing issues.

## Features

ZMK is currently missing some features found in other popular firmware. This table compares the features supported by ZMK, BlueMicro and QMK:

 
|   **Feature**                                                                                          |     ZMK     |   BlueMicro  |     QMK     |
|--------------------------------------------------------------------------------------------------------|:-----------:|:------------:|:-----------:|
| Low Latency BLE Support                                                                                |     ✅      |       ✅    |             | 
| Multi-Device BLE Support                                                                               |     ✅      |              |             |
| USB Connectivity                                                                                       |     ✅      |              |      ✅     |
| User Configuration Repositories                                                                        |     ✅      |              |             |
| Split Keyboard Support                                                                                 |     ✅      |      ✅      |     ✅     |   
| [Keymaps and Layers](behavior/layers)                                                                  |     ✅      |      ✅      |     ✅     |
| [Hold-Tap](behavior/hold-tap) (which includes [Mod-Tap](behavior/mod-tap) and [Layer-Tap](behavior/layers/#layer-tap)) |     ✅      |     ✅    |    ✅   | 
| [Basic Keycodes](behavior/key-press)                                                                     |     ✅     |      ✅      |    ✅     |
| [Basic consumer (Media) Keycodes](behavior/key-press#consumer-key-press)                                 |     ✅     |      ✅      |    ✅     |
| [Encoders](feature/encoders)[^1]                                                                         |     ✅     |              |     ✅    |
| [OLED Display Support](feature/displays)[^2]                                                             |  🚧        |    🚧        |    ✅     |
| [RGB Underglow](feature/underglow)                                                                       |     ✅     |      ✅      |     ✅    |
| One Shot Keys                                                                                            |  🚧        |    ✅        |     ✅    |
| Combo Keys                                                                                               |  🚧        |              |     ✅    |   
| Macros                                                                                                   |  🚧        |      ✅     |     ✅     |
| Mouse Keys                                                                                               |             |     ✅      |     ✅     |
| Low Active Power Usage                                                                                   |     ✅     |              |            |
| [Low Power Sleep States](https://github.com/zmkfirmware/zmk/pull/211)                                    | 🚧         |      ✅      |            |
| [Low Power Mode (VCC Shutoff)](https://github.com/zmkfirmware/zmk/pull/242)                              | 🚧         |               |           |
| [Battery Reporting](https://github.com/zmkfirmware/zmk/issues/47)                                        | 🚧         |      ✅      |            |
| Shell over BLE                                                                                           |            |              |             |   
| Realtime Keymap Updating                                                                                 |     💡      |             |   ✅        |
| AVR/8 Bit                                                                                                |             |             |    ✅       |
| [Wide Range of ARM Chips Supported](https://docs.zephyrproject.org/latest/boards/index.html)             |    ✅       |             |             |
[^2]: Encoders are not currently supported on peripheral side splits.  
[^1]: OLEDs are currently proof of concept in ZMK.  

## Code Of Conduct

Please note that this project is released with a
[Contributor Code of Conduct](https://www.contributor-covenant.org/version/2/0/code_of_conduct/).
By participating in this project you agree to abide by its terms.