For an open-source FDM base

Prusa Research Original Prusa MK4S

An open-frame FDM printer with a 250 × 210 × 220 mm build volume per Prusa Research, a color touchscreen, and an optional MMU3 for multicolor.

In short The Prusa MK4S is an open-frame filament (FDM) 3D printer with a 250 × 210 × 220 mm (9.8 × 8.3 × 8.7 in) build volume. Prusa Research claims a 290 °C (554 °F) nozzle and a 120 °C (248 °F) bed; the printer measures 500 × 550 × 400 mm (19.7 × 21.7 × 15.7 in) and weighs 7 kg (15.4 lb).

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Documentary analysis · Not personally tested

FDM · Open frame

Image provided by Prusa Research. The pictured equipment does not establish the bundle contents.

250×210×220mmBuild volume

290°CMax nozzle temp

120°CMax bed temp

7kgWeight

Why consider it?

An open-source design with the Nextruder extruder, 360° part cooling and an ecosystem of parts and print profiles thoroughly documented by Prusa Research.

What to verify

The chassis stays open by default: the enclosure and filter are separate add-ons worth planning for regular ABS or ASA use.

Prusa MK4S specifications

Technology: Filament (FDM)
Build volume: 250 × 210 × 220 mm (9.8 × 8.3 × 8.7 in)
Printer dimensions: 500 × 550 × 400 mm (19.7 × 21.7 × 15.7 in)
Weight: 7 kg (15.4 lb)
Enclosure: Open frame
Max nozzle temperature: 290 °C (554 °F)
Max bed temperature: 120 °C (248 °F)
Multicolor: Optional MMU3, up to 5 materials, sold separately from the printer.
Materials: PLA, PETG, Flex, PVA, PC, PP, CPE, and PVB per the spec sheet; ABS, ASA, HIPS, and PA with the optional Prusa enclosure and filter.
Screen: 3.5-inch touchscreen
Built-in camera: No
Connectivity: Ethernet, Wi-Fi
Listed features: Auto bed leveling, filament runout sensor

Printer 500 × 550 × 400 mmBuild volume 250 × 210 × 220 mm

How much space does it need?

The Prusa MK4S measures 500 × 550 × 400 mm (19.7 × 21.7 × 15.7 in) for a 250 × 210 × 220 mm (9.8 × 8.3 × 8.7 in) build volume: the dashed box is the printer, the solid cube the largest theoretical part, about 11% of the machine’s volume. Add room for the spool or multicolor unit, cables and ventilation.

Source: official Prusa Research pages (prusa3d.com), checked September 28, 2026. Manufacturer claims, not our measurements. Build volume is nominal: orientation, supports and reserved zones can reduce the usable space.

Compare the Prusa MK4S

Prusa MK4S vs Prusa CORE One+CORE One+ vs MK4S: Which Prusa to Pick?

Which projects is it for?

The MK4S is an open-frame FDM printer with a build volume of 250 × 210 × 220 mm per Prusa Research, a direct successor to the MK4 with a redesigned 360° cooling system and a high-flow Nextruder. It targets the do-everything workshop: functional parts, prototyping, and everyday PLA or PETG printing.

Available as a kit or pre-assembled, it suits both makers who want to understand their machine and users who prefer a ready-to-run setup, since both versions share the same mechanics and the same advertised performance.

Materials and setup

Prusa Research lists PLA, PETG, Flex, PVA, PC, PP, CPE, and PVB in standard configuration, with a hotend up to 290°C and a heatbed up to 120°C. ABS, ASA, HIPS, and PA require the optional Prusa enclosure with filtration.

Multicolor isn't native: adding the MMU3, sold separately, allows up to 5 materials or colors on the same part, using Prusa's own cutting-and-purge system.

What the bundle includes or not

Per Prusa Research's listing, the kit version includes the components to assemble, the power cable, a printed handbook, and access to the online manual; the assembled version ships ready to print with a smooth PEI sheet.

The 3.5-inch color touchscreen is standard on the MK4S. The enclosure, MMU3, and smoke filter remain separate add-ons: check precisely what a listing includes before comparing prices across retailers.

Alternatives to compare

For an enclosed chassis with active chamber heating on a similar bed size, the CORE One is the direct comparison at Prusa Research. The Prusa Research page places the MK4S within the rest of the lineup, including the more compact MINI+.

The FDM vs resin guide helps compare the MK4S against a machine like the SL1S SPEED depending on how much detail you need.

Frequently asked questions

What is the build volume of the Prusa MK4S?

Prusa Research lists a 250 × 210 × 220 mm (9.8 × 8.3 × 8.7 in) build volume (width × depth × height). That is the largest theoretical part size; supports, brim and orientation reduce the usable space.

How big is the Prusa MK4S?

According to Prusa Research, the Prusa MK4S measures 500 × 550 × 400 mm (19.7 × 21.7 × 15.7 in) (width × depth × height) and weighs 7 kg (15.4 lb). Leave extra clearance for the spool, cables and airflow, and more if you add a multicolor unit.

Is the Prusa MK4S enclosed?

No, it is an open-frame printer. It suits PLA and PETG; ABS and ASA are better handled by an enclosed machine. Its nozzle reaches 290 °C (554 °F) and its bed 120 °C (248 °F).

Does the MK4S have an enclosed chamber?

No, it ships as an open frame. Prusa Research sells an optional enclosure as a separate accessory to stabilize ambient temperature and filter fumes.

Is multicolor included with the MK4S?

No, the MMU3 that enables up to 5 materials is a separate accessory. The base printer runs one material or color at a time.

Should you pick the kit or the assembled version?

Both share the same mechanics and the same advertised performance per Prusa Research; the kit requires assembly, while the assembled version is ready to print out of the box.

Similar printers to compare

CrealityEnder-3 V3 SE220 × 220 × 250 mm · Open frame · 250 mm/s

FlashforgeAD5X220 × 220 × 220 mm · Open frame · 600 mm/s

FlashforgeAdventurer 5M220 × 220 × 220 mm · Open frame · 600 mm/s

Sources and limits

Source: official Prusa Research pages (prusa3d.com), checked September 28, 2026. Manufacturer claims, not our measurements.
How we assess specifications

We have not measured noise, real printing speed, accuracy or reliability, so none of these is rated here.