<p><a href="https://i.sstatic.net/1ldX4.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/1ldX4.png" alt="Left right" /></a></p>
<p><a href="https://i.sstatic.net/TtrmF.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/TtrmF.png" alt="Filament sensors" /></a></p>
<p>The MK3 has 4 pins on the filament sensor, the MK3S has only 3 pins. While you need to take the extruder apart to see that, you can also have a look at the cable instead:</p>
<p><a href="https://i.sstatic.net/5C6JE.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/5C6JE.png" alt="Filament sensor cable" /></a></p>
<p>Matching the sensor, the MK3 has a 4 strand wire including blue and the MK3S has a 3 strand cable without blue.</p>
<p><a href="https://i.sstatic.net/nuCqp.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/nuCqp.png" alt="Bearing clips" /></a></p>
<p>Looking under the heatbed, you'll find the MK3 bearings are fixed with U-bolts while the MK3S has broader bearing clips.</p>

CC BY-SA 4.0
2022-11-11T14:26:43.073Z
You list three differences. Did you ever find out the differences mentioned in your other sub-questions, such as the minor changes to the plastic parts of the extruder?
Greenonline
CC BY-SA 4.0
2022-11-11T14:40:49.843Z
@Greenonline: since I don't own a MK3S, I wasn't able to check for differences
Thomas Weller
CC BY-SA 4.0
2021-07-13T14:02:42.963Z
2021-07-13T14:02:42.963Z
Thomas Weller
<p>On the LCD, the MK3 will show <strong>Original Prusa MK3 OK</strong>, while the MK3S/+ will show <strong>Original Prusa MK3S OK</strong>. This will only work if you have the stock firmware installed.</p>

CC BY-SA 4.0
2022-11-10T17:17:21.323Z
2023-03-18T20:38:26.717Z
2023-03-18T20:38:26.717Z
3DCoded
<p>I have a Prusa i3 MK3 or maybe it was upgraded to a i3 MK3S.</p>
<p>How can I figure out?</p>
<p>The <a href="https://shop.prusa3d.com/en/original-prusa-i3-mk3s/1390-original-prusa-i3-mk3-to-mk3s-upgrade-kit.html" rel="nofollow noreferrer">description of the upgrade kit</a> talks about</p>
<ul>
<li>the SuperPINDA (how is it different from the old one?)</li>
<li>a number of small changes (which?)</li>
<li>improved plastic parts (which parts, how are they different?)</li>
<li>metal clips (where to look for them?)</li>
<li>a number of minor changes to the extruder plastic parts (which ones, before and after?)</li>
</ul>
<p>I'd like to figure that out without taking the printer apart.</p>

<prusa-i3>
Distinguish i3 MK3 from i3 MK3S
Thomas Weller
# Distinguish i3 MK3 from i3 MK3S

(Asked by: username_0 on 2021-07-13)

I have a Prusa i3 MK3 or maybe it was upgraded to a i3 MK3S.

How can I figure out?

The [description of the upgrade kit](https://shop.prusa3d.com/en/original-prusa-i3-mk3s/1390-original-prusa-i3-mk3-to-mk3s-upgrade-kit.html) talks about

* the SuperPINDA (how is it different from the old one?)
* a number of small changes (which?)
* improved plastic parts (which parts, how are they different?)
* metal clips (where to look for them?)
* a number of minor changes to the extruder plastic parts (which ones, before and after?)

I'd like to figure that out without taking the printer apart.

**Tags:** prusa-i3

---

## 2 answers

### Answer by username_0 on 2021-07-13. Score: 4 | Accepted answer

[![Left right](https://i.sstatic.net/1ldX4.png)](https://i.sstatic.net/1ldX4.png)

[![Filament sensors](https://i.sstatic.net/TtrmF.png)](https://i.sstatic.net/TtrmF.png)

The MK3 has 4 pins on the filament sensor, the MK3S has only 3 pins. While you need to take the extruder apart to see that, you can also have a look at the cable instead:

[![Filament sensor cable](https://i.sstatic.net/5C6JE.png)](https://i.sstatic.net/5C6JE.png)

Matching the sensor, the MK3 has a 4 strand wire including blue and the MK3S has a 3 strand cable without blue.

[![Bearing clips](https://i.sstatic.net/nuCqp.png)](https://i.sstatic.net/nuCqp.png)

Looking under the heatbed, you'll find the MK3 bearings are fixed with U-bolts while the MK3S has broader bearing clips.

> **Comments:**
> **username_1**: You list three differences. Did you ever find out the differences mentioned in your other sub-questions, such as the minor changes to the plastic parts of the extruder?  
> **username_0**: @Greenonline: since I don't own a MK3S, I wasn't able to check for differences  

---

### Answer by username_2 on 2022-11-10. Score: 4

On the LCD, the MK3 will show **Original Prusa MK3 OK**, while the MK3S/+ will show **Original Prusa MK3S OK**. This will only work if you have the stock firmware installed.


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