Mainsail review: an open-source web interface for Klipper-powered 3D printers with live monitoring, macros, and multi-printer management. Free and self-hosted.
Mainsail is a free, open-source web interface for controlling and monitoring 3D printers that run the Klipper firmware. It connects to Moonraker, the API server that bridges Klipper to web clients, to provide a live, browser-based dashboard for starting prints, adjusting settings, and monitoring progress.
Developed by the mainsail-crew open-source community with its first release around 2020, Mainsail has become one of the two dominant web interfaces in the Klipper ecosystem, alongside Fluidd, and is commonly deployed on a Raspberry Pi connected to the printer's control board.
Mainsail provides real-time print monitoring with temperature graphs and progress statistics, macro management for custom G-code routines, and a console for direct G-code interaction and diagnostics. It supports multiple webcam angles and automated timelapse creation through the moonraker-timelapse plugin.
The interface also supports managing multiple printers from a single dashboard and can receive print jobs sent directly from supported slicers. MainsailOS, a companion Raspberry Pi image, bundles Klipper, Moonraker, and Mainsail together for a simplified initial setup.
Mainsail is completely free and open source, with no paid tiers, subscriptions, or licensing fees. It is self-hosted on the user's own Raspberry Pi or single-board computer alongside Klipper and Moonraker.
The project is sustained through voluntary community contributions via GitHub Sponsors rather than commercial sales, and there are no restrictions on the number of printers or users a self-hosted instance can support.
Mainsail is used as a web-based interface for monitoring and controlling 3D printers that run the Klipper firmware.
Yes, Mainsail is free and open-source software with no paid tiers or licensing fees.
Yes, Mainsail connects to a printer running Klipper firmware through the Moonraker API server; it cannot control non-Klipper printers.
Both are open-source web interfaces for Klipper printers built on Moonraker, but they differ in UI design and layout philosophy; choosing between them largely comes down to personal preference.
MainsailOS is a ready-to-use Raspberry Pi operating system image that bundles Klipper, Moonraker, and Mainsail together for a simplified setup.
Yes, Mainsail supports monitoring and controlling multiple Klipper-powered printers from a single dashboard.