"CPU LED is a fantastic little menu bar tool for keeping an eye on your CPU load. [...] So if you're at all concerned about your CPU load and you've got space to spare in your menu bar, give CPU LED a whirl. " (Samuel Gibbs - TUAW)

Do you ever wonder how stressed your CPU is? Sometimes, opening a complex activity monitor while your computer is heavily loaded is too late (or too much). Sometimes all you need to know is that your CPU is working hard.

CPU LED is a very lightweight unobtrusive app that adds a LED in your status bar indicating your CPU activity (coded as light, medium or hard). You can have only one light for all your processors or one per core (your choice). You can also choose the status icon appearance so it blends nicely with your status bar style, and hover with your mouse over the leds to see the current usage % and core temperature.

In order to know what is going on with your computer at a glance, CPU LED is the perfect companion for Disk LED!

See it for yourself.

And if you are using Mac OS X 10.7 Lion, you can also upgrade CPU LED by adding Memory LED!

That small guy will show you how much of your RAM is occupied (LED style), and how much paging is happening (i.e.: RAM to Disk and Disk to RAM operations). Too much paging means your performance is going down the sink...

Now you know how to solve those uncomfortable "I switched apps and my machine is dying" moments! When Memory LED shows that you are running out of memory, just close some programs and you are good to go!

If you are experiencing any problems or would like to send us a suggestion, please contact or tweet us @agileroute and we'll be happy to help you.

What's New

Version 1.3

- Now the four status icons are used to display CPU load.
- Hide status icon for disabled CPU cores.
- Fixed crash when loading a custom icon set for CPU status.
- DiskLED addon: fixed some external devices didn't disappear when unmounted if "Ignore devices that doesn't contain any media inserted" is enabled.

Ratings and Reviews

4.5 out of 5
848 Ratings
848 Ratings

Does what it says, but can be very badly behaved

I used this app since January 2012, when I bought an 8 core MBP and found I could no longer see each core's load in the activity monitor dock (it shows just one bar if you have any more than four cores.) I'm a programmer and I like to see if one of my cores is pegged (usually because I screwed something up.)

So I found CPULed. It's done a reasonable job since then, taking up little room in my menu bar and showing me CPU activity in a neat and reasonably attractive way. The problem is, it's become flaky. When I try to restart the Mac tells me "CPULed cancelled restart." (It restarts anyway.) If I try to quit it, it won't quit. Ever. I can't access its preferences. More recently, I've noticed Finder gradually using up to 100% CPU after an hour or so of uptime; I kill Finder, it creeps back up. I went through all my programs, extensions, plugins and other thingumajigs until I finally stopped CPULed running on startup. Sure enough, Finder is back to normal. All this on Lion, by the way.

I don't necessarily blame CPULed for this. After all, when I first installed it I could open its preferences, I could quit it, and it didn't cancel restart. It was the perfect little app. Finder behaved well too. Maybe it's fought with something I've put on more recently? I don't know. All I do know is that this particular luxury has been uninstalled.

Music Factory Studios

Perfect for Pro who need CPU info

As a audio engineer CPU usage is one of the most important things you need to manage when recording or mixing. Certian audio plugins can use alot of CPU and this app helps us to choose what to use sometimes using a very CPU intensiive plugin might not be the right choice so you watch CPU LED and then choose an alternative that is suitable. I have never had an issue with this app and I like how it shows all threads of the CPU depending on what Mac you have. I own 3 different Macs and each with different CPU configurations, Xeon 8 core Mac Pro it shows 16 bars one for each thread, and Dual core i5 Mac Mini it shows 4 bars for 4 threads and a 15 inch Macbook Pro with an i7 quad core and CPU LED shows all 8 threads this is a great feature but I have to say 16 little Bars on the 8 core Mac Pro forces you to use the more narrow icon sets because it takes up so much space in the toolbar. I just wish There were more in app purchasable icon sets. Even though there is alot of icon sets I would like to see some for the larger cpu sets like guys with Quad i7’s and Xeon Cpu’s. Image the 12 core mac pro with 24 bars on the toolbar you would have no room for anything else or other utility add on apps.

Uncle Gum

Works w Yosemite; no problems

I can’t comment about whether it is super accurate or not, but it does give me some idea that CPU is usually not overtaxed; shows me when something really pushes it (usually just briefly); but most importantly - when something strange is going on. Occasionally I’ll see a regular rhythm of red spikes, or one or more all locked up in red. Sometimes, but sometimes not, my computer well act strangely at the same time - being slow, locked up, some app not responsive, background process or even non-focused app not responsive. It gives me a useful flag to check further. Often a restrat fixes it. The quick link to activity monitor helps & gives more detail. Nice free app!


Raul Ignacio Verano
1.1 MB
OS X 10.6 or later
Age Rating
Rated 4+
© 2011 Agile Route


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