Official documentation can be found at the Marlin Home Page.

Please test this firmware and let us know if it misbehaves in any way. Volunteers are standing by!

Not for production use. Use with caution!

Marlin 2.1 supports both 32-bit ARM and 8-bit AVR boards while adding support for up to 9 coordinated axes and to up to 8 extruders.

This branch is for patches to the latest 2.1.x release version. Periodically this branch will form the basis for the next minor 2.1.x release.

Download earlier versions of Marlin on the Releases page.

Before you can build Marlin for your machine you'll need a configuration for your specific hardware. Upon request, your vendor will be happy to provide you with the complete source code and configurations for your machine, but you'll need to get updated configuration files if you want to install a newer version of Marlin. Fortunately, Marlin users have contributed hundreds of tested configurations to get you started. Visit the MarlinFirmware/Configurations repository to find the right configuration for your hardware. Make sure to select a compatible branch! The Marlin Download Page matches compatible software and configuration packages.

To build and upload Marlin you will use one of these tools:

• The free Visual Studio Code using the Auto Build Marlin extension.
• Marlin is optimized to build with the PlatformIO IDE extension for Visual Studio Code.
• You can also use VSCode with devcontainer : See Installing Marlin (VSCode devcontainer).
• You can still build Marlin with Arduino IDE : See Building Marlin with Arduino. We hope to improve the Arduino build experience, but at this time, PlatformIO is the preferred choice.

Marlin is compatible with a plethora of 32-bit ARM boards, which offer ample computational power and memory and allows Marlin to deliver state-of-the-art performance and features we like to see in modern 3d printers. Some of the newer features in Marlin will require use of a 32-bit ARM board.

Marlin originates from the era of Arduino based 8-bit boards, and we aim to support 8-bit AVR boards in perpetuity. Both 32-bit and 8-bit boards are covered by a single code base that can apply to all machines. Our goal is to support casual hobbyists, tinkerers, and owners of older machines and boards, striving to allow them to benefit from the community's innovations just as much as those with fancier machines and newer baords. In addition, these venerable AVR-based machines are often the best for testing and feedback!

Marlin's Hardware Abstraction Layer provides a common API for all the platforms it targets. This allows Marlin code to address the details of motion and user interface tasks at the lowest and highest levels with no system overhead, tying all events directly to the hardware clock.

Every new HAL opens up a world of hardware. Marlin currently has HALs for more than a dozen platforms. While AVR and STM32 are the most well known and popular ones, others like ESP32 and LPC1768 support a variety of less common boards. At this time, an HAL for RP2040 is available in beta; we would like to add one for the Duet3D family of boards. A HAL that wraps an RTOS is an interesting concept that could be explored.

Did you know that Marlin includes a Simulator that can run on Windows, macOS, and Linux? Join the Discord to help move these sub-projects forward!

The Issue Queue is reserved for Bug Reports and Feature Requests. Please use the following resources for help with configuration and troubleshooting:

• Marlin Documentation - Official Marlin documentation
• Marlin Discord - Discuss issues with Marlin users and developers
• Facebook Group "Marlin Firmware"
• RepRap.org Marlin Forum
• Facebook Group "Marlin Firmware for 3D Printers"
• Marlin Configuration on YouTube

You can contribute patches by submitting a Pull Request to the (bugfix-2.1.x) branch.

• We use branches named with a "bugfix" or "dev" prefix to fix bugs and integrate new features.
• Follow the Coding Standards to gain points with the maintainers.
• Please submit Feature Requests and Bug Reports to the Issue Queue. See above for user support.
• Whenever you add new features, be sure to add one or more build tests to buildroot/tests. Any tests added to a PR will be run within that PR on GitHub servers as soon as they are pushed. To minimize iteration be sure to run your new tests locally, if possible.
  • Local build tests:
    • All: make tests-config-all-local
    • Single: make tests-config-single-local TEST_TARGET=...
  • Local build tests in Docker:
    • All: make tests-config-all-local-docker
    • Single: make tests-config-all-local-docker TEST_TARGET=...
  • To run all unit test suites:
    • Using PIO: platformio run -t test-marlin
    • Using Make: make unit-test-all-local
    • Using Docker + make: maker unit-test-all-local-docker
  • To run a single unit test suite:
    • Using PIO: platformio run -t marlin_<test-suite-name>
    • Using make: make unit-test-single-local TEST_TARGET=<test-suite-name>
    • Using Docker + make: maker unit-test-single-local-docker TEST_TARGET=<test-suite-name>
• If your feature can be unit tested, add one or more unit tests. For more information see our documentation on Unit Tests.

Marlin is constantly improving thanks to a huge number of contributors from all over the world bringing their specialties and talents. Huge thanks are due to all the contributors who regularly patch up bugs, help direct traffic, and basically keep Marlin from falling apart. Marlin's continued existence would not be possible without them.

Marlin Firmware original logo design by Ahmet Cem TURAN @ahmetcemturan.

Marlin is published under the GPL license because we believe in open development. The GPL comes with both rights and obligations. Whether you use Marlin firmware as the driver for your open or closed-source product, you must keep Marlin open, and you must provide your compatible Marlin source code to end users upon request. The most straightforward way to comply with the Marlin license is to make a fork of Marlin on Github, perform your modifications, and direct users to your modified fork.