Should I keep the lid open on MBP when using as a desktop?

I’ve always used my laptops as desktops… connecting them to a keyboard/mouse and external monitors. I leave the lid closed when I do this. Is this OK? I recall reading something suggesting the lid should be open to assist with ventilation. I have two MBPs, a mid 2012 and an early 2015.

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You might get better cooling leaving the lid open, but Macs are designed to operate in “clamshell” mode, so I wouldn’t worry about it. The worst I can see happening is that the fans may run faster/louder than with the lid open.

You might, however, want to leave the lid open, place the laptop next to your external monitor and turn off mirroring in order to work with a dual-screen desktop. I find it is really convenient working this way - I always find myself wanting more screen real-estate and this is a way to get some for free (if you have a place on your desk for the laptop).


Hey thanks! I actually used to do that (leave it open for an extra screen), but then I was given a second monitor, thus the clamshell mode. But, I’ve seen setups with three and more monitors which make me wonder… will the open laptop work as a 3rd monitor?

Depends on the Mac model and the bandwidth used by each display for its selected resolution. Give it a try. If your Mac doesn’t support 3-display operation, then one of the displays won’t have an image, but nothing should fail.

I have a MacBook (so no fan) and an external monitor (and no room to put the open MacBook next to the external monitor). I don’t recall the details, but I had some infrequent anomalous behavior. Once upon a time I picked up up the MacBook and thought the bottom was warm, so I started connecting the USB-C cable to an “up-side-down” MacBook (with the bottom up). Since I don’t recall the problem, I’m not certain that I solved it, but I’m going with that superstition.

That’s not entirely impossible. On most Macs the underside gets warmer than the area above the KB because that its how the internals are connected to the case. So if you flip yours around that puts the hottest part at the top where it can also exchange heat freely with the surrounding air, unlike the usual position where there is very little airflow between the device’s underside and the table merely 1-2 mm away. On MBPs with fans that’s not so much an issue because the fans circulate air and force heat out the back, but on a fanless MacBook where it’s all about convection from the case I can see how putting it so that the bottom faces up could help.


With any INTEL Mac leave the lid open. I burned up a 2008 15" MBP leaving the lid closed. For M1 Macs I doubt it will make any difference. I have a full case on my M1 with no vents and still the fan never runs.

I’m 50/50 on this. I have a 2019 MBP13" and when I was in the office, it was charged/connected to an LG 4K 27". I left the lid closed all the time, but whenever I had shutdown (weekends or not using that week), I had to open the lid to power up, and for the display to get the signal. Once I did that and logged in, I would close the lid. I never had any heat issue. I guess it depends on the model. But then, this is where I whine about how about how Apple charges too much for the Mac Mini, as a $599 MacMini would be ideal for those that have a display and don’t need the portability or the cost.

I’ve been using a various 13" and 15" MBPs over the years in clamshell mode. Never had any issues, apart from loud fans at times of course. I assume that when people run into real trouble with closed lids it’s because they unknowingly had a fan die or the battery failed catastrophically. Those shouldn’t be related to a closed lid, but they will certainly be a bigger problem if the lid is closed when it happens.

I killed a MBP 15" in clamshell mode due to the intense heat. So I guess it depends on what you’re doing with with it. On the other hand if it’s an M1, I don’t think it will make any difference. Two months in and I still haven’t heard the fan or feel it get warm.= and I have it in a $50 case. In contrast if I had done the same with my INTEL Mac, it would have been like a hair dryer.

I use a 2019 13” MBP and have it in clamshell hooked up to a display.
It doesn’t get hot. Periodically the fan will run - but not noticably.
I have it stored vertically in a holder (Omoton).