Prusa MK4 vs MK4S: What Changed, and Whether to Upgrade
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The MK4S is a refinement of the MK4, not a new printer: same 250 × 210 × 220 mm bed, same Nextruder with load-cell probing, same 290 °C and 120 °C limits. It added a 360-degree part-cooling duct that makes PLA overhangs and speed noticeably better, a high-flow-friendly hotend heater, a mount for the Buddy3D camera and revised profiles. Prusa sells an MK4 to MK4S upgrade kit. Upgrade if you print a lot of PLA at speed; skip it if you mostly print PETG and ASA.
Where to buy
Side by side
| Spec | MK4 | MK4S |
|---|---|---|
| Build volume | 250 × 210 × 220 mm | 250 × 210 × 220 mm |
| Extruder | Nextruder, load cell | Nextruder, load cell |
| Max nozzle / bed | 290 °C / 120 °C | 290 °C / 120 °C |
| Part cooling | Single-side duct | 360-degree duct, larger fan |
| Hotend heater | Standard | Revised, high-flow oriented |
| Camera | No mount | Buddy3D mount |
| Nozzle sizes | 0.25 to 0.8 mm | 0.25 to 0.8 mm; high-flow nozzles supported |
| Input shaping | Yes (firmware) | Yes |
| Upgrade path | MK4 to MK4S kit | MK4S to CORE One conversion kit |
What the 360-degree cooling changes
PLA at speed needs the whole perimeter cooled evenly; the MK4’s single-side duct left one face warmer, which showed as overhang droop on one side and limited how fast PLA could go cleanly. The MK4S duct fixes that and is the reason Prusa’s PLA profiles got faster. For PETG and ASA, which want less cooling, the difference is small.
Should an MK4 owner upgrade
- Yes if PLA is your main material and you print overhangs, or you want the camera mount.
- No if you print mostly PETG, ASA or nylon; the MK4 prints those the same.
- Consider instead the MK4/MK4S to CORE One conversion if you want an enclosure and heated chamber; see MK4S vs CORE One.
Buying today
Buy the MK4S; the MK4 is no longer sold new. MK3S+ owners can step through the MK3.9S or MK4S upgrade path; see the MK3 page. Full MK4S detail is on the MK4S page.
The units in the box
The listings are the MK4S kit, the MK4S assembled and a third-party CryoGrip sheet that fits the MK4 family.
FAQ
Do MK4 sheets fit the MK4S? Yes; same bed.
Does the MK4S print faster than the MK4? On PLA, yes through better cooling; the motion system is the same.
LayerWalker
Print defect diagnosis, calibration procedures and parts that actually fit. Corrections welcome through the contact page.
