Prusa MMU3 Gets Massive Speed Boost — New Firmware Cuts Filament Swap Times by 9 Seconds

The MMU3 Gets Its Final Gift From Prusa

Prusa Research has released a firmware update for the Original Prusa MMU3 that dramatically slashes filament change times — cutting up to 9 seconds per swap on the MK4 and XL toolheads. For complex multi-material prints running dozens or hundreds of filament changes, that adds up to hours of real print time saved.

The update was announced on the official Prusa blog on March 23rd, with Jan Olejnik confirming the improvements apply across all supported toolheads. The speed gains come from optimised gear profiles and refined motor acceleration curves — no hardware changes required.

What Changed

The previous firmware already handled the MMU3's selector movement and filament parking sequences, but the new profiles reduce the selector's travel time between slots and tighten the tensioning sequence during loading. Prusa describes it as a farewell firmware boost for the MMU3, which is being replaced in the product line by the upcoming INDX system.

According to the Prusa blog, the improvements are most noticeable on the XL with its larger build area, where multi-material prints tend to be longer and filament swaps more frequent. Users on the MK4 also see significant improvements, though the gains are proportional to the number of swaps in a given print.

The Bigger Picture — INDX Is Coming

Prusa has been clear that the MMU3 is approaching end-of-life. The new INDX system, expected later in 2026, is being positioned as the successor — promising further speed improvements and a redesigned filament path built from the ground up. The firmware boost is effectively a parting gift to the MMU3's loyal user base.

The MMU3 has been one of the most popular multi-material upgrades for Prusa printers since its launch, and the community has already been sharing before-and-after times on print jobs. The consensus: for prints with 50+ filament changes, the time savings are real and noticeable.

Core One L Support Confirmed

Alongside the speed boost, Prusa confirmed that the CORE One L will also support the MMU3 going forward, maintaining the system's compatibility across the current printer lineup. Users can update via Pronterface or the PrusaSlicer firmware updater.

Should You Update?

Short answer: yes. If you own an MMU3 and run multi-color or multi-material prints regularly, the update is free, takes five minutes, and the speed improvements are measurable. The only caveat is that if you have custom slicing profiles with tuned loading sequences, you may want to re-calibrate after updating to take full advantage of the new profiles.