Magnify your Mac screen

For some people with eyesight problems the menus and other User Interface (UI) presentation is too small to see in comfort. Apple’s “public” solution to this is via the System Prefs, Universal Access and Zoom. But that isn’t very appealing, since it just enlarges all the pixels, making everything blocky.

They have had a far superior solution for years now, but for reasons unknown to me, it has been limited to developers. Fortunately, it’s not geeky at all: it’s just a program you run, and choose the amount of magnification you want with a little slider. That’s it.

Equally fortunately, getting access to the developer tools which have this program (the program is named “Quartz Debug”) is absolutely free. What’s more, if you have a recent OSX install disc, you very well may already have the installer for Developer Tools.

I have never noticed anything untoward with the OS because I have this installed. You will, in short, notice absolutely nothing new, with exception of a new folder: “Developer” on your hard drive.

If you have the developer tools installer on your OSX install disc, just go ahead and install it, and skip down to part 2, below. If not, here’s how to go online and get it.

Google “ADC member site” and click on the “join now button”

or just visit here: and choose the Free membership down in the lower left corner.

Either way, fill in the form to become an ADC member.

Log in, and click on downloads, and look for “Developer Tools” (probably in a menu on the right.) (You can also find the tools by looking on

On the resulting page look for “Xcode 3.2.1 Developer Tools” (the version number 3.2.1 may be higher when you read this; you’re looking for the current version of Xcode Developer Tools).

The download is about 900Mb, so it will take a while.

Part 2.

Once you get the .dmg file, double click it to mount it, and then double click the installer to install the tools. This will create a new folder on your hard drive, cleverly called “Developer.” This folder must remain where it is.

NOW… here’s how you get your UI to enlarge so that you can see everything more easily.

Open the developer folder. In it, open the Applications folder. In it open the Performace Tools folder, and in there, you will see a program called “Quartz Debug.”

This is the program you want to run to enlarge your UI. (You may want to simply place an alias to it on your desktop.)

Double click the Quartz Debug program to run it. Go to the Window menu and choose “UI Resolution” (or just press command 2.)

Select the level of magnification you want. I suggest you start with 1.5 or 2.

You will NOT see anything happen immediately. However, now when you start up any modern program, you’ll see the enlarged UI. Launch Mail or Safari to see the effect. Quartz Debug needs to stay running. (Not all programs will respond properly to the enlargement, but most will.)

The effect takes place when you launch a program. It will not affect currently running programs. That means if you want to see a larger UI in a program you have running at the time you run Quartz Debug, you’ll have to quit that program and re-launch it. Yes, that means the Finder too; it’s just another program. To relaunch the Finder, go to the Apple menu, and choose “Force quit…” and select the Finder from the list. (Instead of “quit” it will say “relaunch” instead.)

Also note that the success of Quartz Debug depends on your video card, and how well it support the Quartz rendering engine. The only to go is to try it and see. If you don’t like it, or can’t use it, just ignore it. Your OS will be fine… or at least mine is.

That’s it. From now on, anytime you want a larger UI, just run Quartz Debug, and you’re set to go!