Changing Application Opacity


Is there a way to change an applications opacity? It'd be really nice to have a small, clear iTunes window if you ask me...

And another, unrelated thing. When I play sound with any application, I get no output from my subwoofer. If I have the balance over to one side a bit, like a little bit to the left, I get bass response. WTF? Why is this happening?

Yes! There is a way. The property is called "Opaqueness". A friend of mine helped me set my terminal/console up so that it was semi-transparent. It's awesome when you set the background color. I'm in the process of figuring out how he set it, and if it's possible to use the same property on other apps. I'll let you know what I find! I do know that the value is a percentage, so it would be like:

Opaqueness = 0.8

or something like that.

Well, I found out how to change the terminal's opacity anyway. Here's what you do:

vi /Users/<you>/Library/Preferences/

Add the lines:


within the <dict> </dict> tags. Note that .8 is the percentage of Opaqueness you want. My terminal uses a blue background with white text and looks really smooth. If I figure out how to change the opacity of any other apps, I'll let you know.

you can use the property list editor app that's on the dev tools cd to do this too... just open terminal's plist file with that and add/edit the TerminalOpaqueness key/value pair.
I have already set my terminal's opacity, I was just wondering if I could do the same to apps.

I'm planning on opening a mac os X site:

See yeah later. If you solve the problem email me, its quicker...


<img src="">
Okay, so, if you're not careful you can do a lot of damage, but you all need to stop being afraid of the command line.

There are two somewhat long process for changing the opacity of the Terminal window, when it can be achieved very easily.

Open Terminal

At the prompt type

defaults write TerminalOpaqueness '0.xx'

where xx is a value from 01 to 99
It's possible to set the opacity of any CoreGraphics surface but it's a non-trivial hack.

You can look at the CoreGraphics headers to start if you want to write such a hack.
We already know how to make our term windows cool and opaq. We want to know -HOW- to do this with other app's.

I dont even know where to begin to look for CoreGraphics settings. Is this going to be a per app hack? (Which I prefer)
It's a per-surface hack, if you implement it. I would imagine hitting a key modifier then clicking on any surface would bring up a slider to change it's opacity.

At least that's how I would do it.
That makes no sense. What are you going to do, make a popup menu with 256 items?

A popup slider would actually work.

Anyway nobody is going to write this hack
as in a slider in a submenu, or a 'Set Window Opacity...' item that shows a dialog.

You can't just use modifier-click, because every possible key combination is going to be taken by some app or other.
if anyone wants to add this to an app they're writing, read the AppKit release notes for NSWindow