Prusa Research Original Prusa MK4S
D2 Cloud-Optional — Full function with the router off.
The unplug test
Block internet at the router and the MK4S keeps printing exactly as before: slice a model in PrusaStudio/PrusaSlicer on your own computer, copy the G-code to a USB drive, and print from the printer's own screen. The built-in PrusaLink web server still serves a local control and monitoring page over your LAN with no internet required. The only things that stop working are Prusa Connect's remote (over-the-internet) monitoring and the Prusa mobile app, both of which are opt-in extras layered on top of a printer Prusa explicitly documents as usable with 'no drawbacks or limitations' offline. The Wi-Fi module itself is a physically removable ESP add-on, not a soldered-in requirement.
Why this tier: Prusa operates a real vendor cloud (Prusa Connect) and sells an optional Wi-Fi/NFC-equipped printer, but Prusa's own documentation states the MK4S is designed for native offline use, completes setup and prints with no account of any kind, and reaches 100% of core function (slicing on a computer, printing from a USB drive, monitoring over the local network via the built-in PrusaLink web interface) with the printer never touching Prusa's servers.
Specifications
| Account required | none |
|---|---|
| Works offline | fully |
| Lost when offline | Prusa Connect remote (over-internet) monitoring and control, Prusa mobile app, cloud print-queue / multi-printer fleet dashboard |
| Forced firmware updates | unknown |
| Radios | wifi, nfc |
| FCC ID | not checked |
| Local control | rest |
| Phones home | unknown |
| Self-hostable | full — fully replaceable on your own hardware PrusaLink, built into the printer's own firmware, already reproduces Prusa Connect's monitoring, file-upload and print-control functions entirely on the local network with no cloud account; OctoPrint is also compatible for owners who want a Raspberry Pi-hosted alternative. |
| Parts available | yes |
| Availability | in stock |
| Price band | $620-770 (seen 2026-09-03) |
| Vendor risk | 0 / 3 |
Where to buy
Open questions
- No FCC ID was located for the ESP Wi-Fi add-on module in the time available; Prusa's FCC grantee code was not confirmed, so this is an unresolved lookup rather than a meaningful absence.
- Whether firmware updates can be declined, or are ever pushed automatically over Prusa Connect, was not confirmed from documentation reviewed.
- Whether the standard setup wizard offers an explicit 'skip network setup' option on first boot, versus simply not forcing one, was not directly observed (based on documentation, not a hands-on unboxing).
Sources
Class A is primary (manual, FCC filing, teardown). Class B is corroborated community reporting. Class C is never sufficient alone.
- A https://www.prusa3d.com/product/original-prusa-mk4s-3d-printer-2/
Manufacturer product page: states the MK4S 'has been designed for native offline use, so if you don't want to use the network services, you don't have to,' lists connectivity as Ethernet, NFC receiver and a removable ESP Wi-Fi module delivered with the printer, USB drive printing, and kit/assembled pricing of $620.84/$765.92. — accessed 2026-09-03 - A https://help.prusa3d.com/article/prusa-connect-and-prusalink-explained_302608
Prusa's own help center distinguishes cloud-based Prusa Connect from locally-hosted PrusaLink (built into the MK4S, accessed by entering the printer's own IP address in a browser), states neither service is required for basic printing via USB or the onboard controls, and that PrusaLink provides monitoring, file upload and print control without any internet access or cloud account. — accessed 2026-09-03
History
- 2026-09-03 — First published at D2.
Last verified 2026-09-03 — 3 days ago.