Every FDM printer needs firmware to turn G-code into stepper motor pulses, and for most of the hobby's history that meant one project: Marlin. Klipper's rise over the past several years has turned "which firmware" into a real fork in the road, and the two projects have answered the same problems — vibration-induced ringing, extrusion lag on corners — in architecturally different ways. This is a head-to-head: what each firmware actually is, how their motion-smoothing features compare on paper, which major manufacturers ship which one, and a practical framework for deciding whether to switch.

Marlin: All the Firmware Lives on the Board

Marlin is a single codebase that runs entirely on the printer's own microcontroller — no companion computer, no network dependency, no second point of failure. Its own project README describes it as firmware that "supports both 32-bit ARM and 8-bit AVR boards," adding that Marlin "originates from the era of Arduino based 8-bit boards, and we aim to support 8-bit AVR boards in perpetuity" while also running on modern STM32 and ESP32 controllers. A Hardware Abstraction Layer gives "a single code base that can apply to all machines," so the same project spans an 8-bit budget board and a high-end 32-bit controller. That monolithic design is Marlin's core appeal: flash it once, unplug the USB cable, and the printer runs itself — no Raspberry Pi to power, patch, or SSH into.

Klipper, Briefly

Klipper takes the opposite approach: it splits the job between an application processor (typically a Raspberry Pi) and the printer's microcontroller. Per Klipper's own Features page, "the application processor determines when to step each stepper motor, it compresses those events, transmits them to the micro-controller, and then the micro-controller executes each event at the requested time" — with step timing accurate to 25 microseconds. That extra compute budget is why Klipper became the default for the high-speed CoreXY builds dominating today's enthusiast scene. We've covered that architecture and its input-shaping workflow in full elsewhere; see our complete Klipper guide for the deeper walkthrough. Here, the point is simpler: Klipper needs a host computer running full time, and that's the tradeoff for its headroom.

Input Shaping and Pressure Control: The Gap Has Narrowed

This used to be Klipper's clearest advantage, and it still leads, but Marlin has closed real ground. Klipper's Features page describes "Input Shaping" as a way "to reduce the impact of vibrations on print quality," cutting or eliminating the ringing pattern that shows up on fast prints, alongside "Smooth Pressure Advance," a physics-based model of nozzle pressure that reduces ooze without introducing sudden speed changes.

Marlin's answer arrived later but is now built into the open-source project rather than bolted on. Per Marlin's own Input Shaping documentation, "Marlin first introduced ZV Input Shaping in version 2.1.2," a shaper controlled via G-code M593 that works by echoing a delayed, half-amplitude step signal to cancel ringing on the X, Y, and Z axes. The docs concede "more advanced input shapers may be able to cancel more complex acoustic waves" than the simple ZV shaper — the gap Marlin closed next. A newer Fixed-Time Motion system, contributed by Ulendo.io and merged into mainline Marlin starting with the 2.1.3 branch, adds ZV, ZVD, EI, 2HEI, 3HEI, and MZV shaper types — the same shaper family Klipper users recognize — extended across all nine of Marlin's axes and eight extruders. On extrusion, Marlin's Linear Advance plays the same role as pressure advance: it treats filament between drive gear and nozzle "as a spring," and the current 1.5 implementation runs the extruder "at a fixed speed offset during pressure adjustment" to stay within the machine's jerk limits.

Net result: both firmwares now ship real, tunable input shaping and pressure/advance compensation in their free, open-source base. The remaining gap is tooling, not capability — Klipper's accelerometer-driven `SHAPER_CALIBRATE` macro is more turnkey than Marlin's manual ringing-tower prints, and Klipper's finer step-timing still gives it more headroom at extreme speeds. But "Marlin can't do input shaping" has not been accurate since 2.1.2.

Who Ships What, Stock

Bambu Lab ships neither. Per discussion on the company's own community forum, Bambu's printer firmware is closed source and written from scratch — not a Marlin or Klipper derivative — with X1-series controllers running embedded Linux under a proprietary real-time motion layer. There is no official Klipper support; projects like X1Plus exist specifically to add Klipper-adjacent access by bypassing Bambu's authorization controls.

Prusa ships Marlin, heavily modified. The official Prusa-Firmware-Buddy repository, covering the MK4, CORE One, MK3.5/3.9, MINI, and XL, lists "Marlin" as its "3D printing core driver," with Prusa's own UI, WebUI, and hardware code layered on top.

Creality ships both, depending on the printer. Its legacy Ender-3 V2 downloads page lists firmware filenames like "Marlin2.0.8.2-HW-V4.2.2" — stock Marlin. Its newer speed machines run the opposite: the official Ender-3 V3 KE Klipper repository describes itself as a "clone from" the Klipper3d project, with Creality's own touch-UI layer (branded Creality OS) on top — the same pattern used on the K1-series machines.

Voron ships nothing itself — it's an open-hardware design, not a company — but its official build documentation is unambiguous: "All stock Voron printers run on the Klipper firmware," with Mainsail or Fluidd as the recommended web interfaces.

Switch or Stay: A Practical Framework

Consider Klipper if you want multi-material or toolchanger setups where its macro system and community configs are the path of least resistance, you're chasing print speeds where finer step-timing and easier shaper auto-calibration pay off, you want a browser-based UI like Mainsail or Fluidd instead of an LCD menu, or you're building a Voron or similar open-hardware CoreXY where Klipper is the documented default.

Stay on Marlin if simplicity matters more than the last 10% of speed: no Raspberry Pi to power or troubleshoot separately from the printer; an out-of-the-box Marlin fork (Prusa's Buddy firmware, Creality's Ender-3 line) that already does what you need, including input shaping via Fixed-Time Motion where the board supports it; or a machine whose warranty assumes stock firmware, where an unsupported Klipper flash would void it. For a single reliable printer running functional parts, Marlin's built-in input shaping and Linear Advance now cover most of what used to require switching — the case for Klipper rests more on ecosystem and tuning tools than a capability gap.

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