Mainsail vs Fluidd: Choosing the Right Klipper Web Interface in 2026

Klipper Needs a Frontend — But Which One?

Klipper firmware does not come with its own user interface. It runs as a background service on a Raspberry Pi (or similar SBC) and communicates through Moonraker, an API layer that handles file management, printer control, and status updates. To actually control your printer — start prints, monitor temperatures, edit configs — you need a web frontend that talks to Moonraker.

The two leading options are Mainsail and Fluidd. Both are free, open-source, and browser-based. Both do the same fundamental job. But their design philosophies differ enough that most Klipper users develop a strong preference. This guide breaks down the real differences so you can choose without installing both (though you absolutely can run them side by side).

Mainsail: Speed and Efficiency First

Mainsail takes a minimalist approach. The interface is clean, fast, and information-dense. It loads quickly even on a Raspberry Pi 3 and wastes no bandwidth on animations or visual flourishes.

Key Features

• Macro management — Mainsail’s Macro Store provides pre-built macro scripts for common tasks (bed leveling sequences, filament changes, maintenance routines). You can browse, install, and customize macros without writing G-code from scratch.
• Config editor with syntax highlighting — edit printer.cfg, moonraker.conf, and other Klipper configs directly in the browser with error checking that catches typos before they cause firmware crashes.
• System resource monitoring — real-time CPU, memory, and disk usage displayed in the interface. Useful for diagnosing performance issues on underpowered Pi boards.
• Customizable dashboard — rearrange panels, hide unused sections, and create multiple dashboard layouts for different use cases (printing, maintenance, calibration).
• Webcam integration — supports multiple camera feeds with configurable aspect ratios and adaptive streaming quality.
• Timelapse plugin support — works with the popular moonraker-timelapse plugin for automated print timelapses.

Who It Suits

Power users who prioritize speed, keyboard shortcuts, and information density. If you treat your printer like a production machine and want maximum data visible at a glance, Mainsail is your interface.

Fluidd: Visual Polish and Accessibility

Fluidd takes a more visual approach. The interface is modern, with smooth animations, rounded corners, and a layout that feels more like a consumer app than a machine control panel.

Key Features

• Hot reload configuration — change printer.cfg settings and apply them without restarting the Klipper service. This is a genuine time-saver during calibration sessions where you are tweaking pressure advance or PID values repeatedly.
• Intuitive temperature controls — large, touch-friendly temperature graphs and preset buttons. Works well on tablets and touchscreens mounted near the printer.
• Drag-and-drop file management — upload G-code files by dragging them into the browser. Simple but effective.
• Responsive mobile layout — Fluidd’s mobile view is more polished than Mainsail’s, making it better for monitoring prints from your phone.
• Color-coded status indicators — at-a-glance printer status with clear visual cues for heating, printing, idle, and error states.

Who It Suits

Users who value aesthetics, touchscreen operation, and a gentler learning curve. If you want your printer dashboard to feel modern and approachable — or if you monitor prints primarily from a phone or tablet — Fluidd delivers a smoother experience.

Direct Comparison

Performance on Low-Power Hardware

Mainsail is noticeably lighter. On a Raspberry Pi 3B (which many Klipper users still run), Mainsail loads 1-2 seconds faster and uses less memory. On a Pi 4 or Pi 5, the difference is negligible. If you are running Klipper on an older or budget SBC, Mainsail’s efficiency matters.

Configuration Editing

Both offer in-browser config editors. Mainsail’s editor includes syntax highlighting and basic error detection that catches common mistakes (missing colons, invalid section names). Fluidd’s editor is functional but lacks these quality-of-life features. For heavy config editing, Mainsail wins.

Mobile Experience

Fluidd’s responsive design adapts better to small screens. Temperature controls are touch-optimized with large targets, and the layout reorganizes cleanly on portrait-oriented phones. Mainsail works on mobile but feels cramped — it was designed desktop-first.

Plugin Ecosystem

Both interfaces support Moonraker plugins (timelapse, power control, update manager). Mainsail’s Macro Store is a unique advantage — it is effectively a curated library of community-contributed automation scripts that Fluidd does not replicate.

Updates and Development

Both projects are actively maintained with regular releases. Mainsail tends to release larger updates less frequently, while Fluidd ships smaller incremental updates more often. Both have responsive communities on GitHub and Discord.

Can You Run Both?

Yes. Since both are just static web files served by a local web server, you can install Mainsail and Fluidd on the same Pi and access each on a different port. KIAUH (Klipper Installation And Update Helper) makes this trivial — select both during setup, and you get Mainsail on port 80 and Fluidd on port 81 (or whichever ports you configure).

This is genuinely the best way to decide. Spend a week printing with each and see which one you reach for naturally.

What About OctoPrint?

OctoPrint is the other major web interface for 3D printers, but it targets Marlin firmware primarily. While an OctoKlipper plugin exists, it adds complexity without matching the native Klipper integration of Mainsail or Fluidd. If you are running Klipper, use Mainsail or Fluidd. If you are running Marlin and want remote monitoring, OctoPrint remains excellent — see our OctoPrint remote access guide for setup instructions.

For more on Klipper setup in general, check our Klipper installation guide and Klipper vs Marlin comparison.

Conclusion

Mainsail and Fluidd are both excellent Klipper frontends. Mainsail is faster, more information-dense, and better for power users who live in config files. Fluidd is prettier, more touch-friendly, and better for users who monitor prints from mobile devices. Neither is objectively superior — they are different tools optimized for different preferences. Install both via KIAUH, use each for a week, and let your habits decide.