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To download Decelerate from the Mac App Store, you need a Mac with OS X 10.6.6 or later. Learn More.


By Bulldozer Software

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Decelerator allows you to customize the acceleration setting of your mouse or trackpad. While System Preferences can change the tracking speed, it doesn't actually allow you to modify the factory default acceleration setting. There are a number of reasons you might want to do this:

1. Gamers often disable mouse acceleration entirely to gain a competitive edge in "twitch" reflexes. With mouse acceleration off, a distance on-screen corresponds with an exact distance your hand must move, and is unaffected by the speed with which it moves there.

2. Windows users often find Mac OS X's relatively high mouse acceleration disorienting and frustrating. Lowering the mouse acceleration can go a long way to easing the transition to a new operating system.

3. Some people prefer higher or lower acceleration settings for many reasons both logical and illogical. If you're one of those people, then Decelerator allows you to tweak to your heart's content.

Decelerator costs $1 (and no, I don't believe in reminding you how that compares to a cup of coffee, though I guess I just did!), with 70 cents of each purchase going to the "feed a starving developer" fund. I've been using the app very happily for the last few months, and I hope it's as useful (in fully unproductive ways!) for you as it has been for me. If you have any comments or suggestions, I'd love to hear them on the forums at

One more thing. I hate it when developers charge upgrade fees to users, so new Decelerator versions will ALWAYS be free for existing users.


Ok, two more things. If you have a problem, please please please contact me instead of (or at least in addition to) submitting a bad review. Developers have no way of contacting reviewers for details, and since I am unfortunately confined to only 5 senses, I can't actually fix "Horrible aplication I ever bought". I tried to address the 3 negative reviews so far here:


Version 1.0:
* First public release!


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Customer Reviews

Not Acceleration

What I am seeing on Snow Leopard is that it is just altering the tracking speed. If I set tracking to medium, close System Preferences, set Decelerator to maximun, and open System Preferences -- the tracking speed has been altered to max. Tracking speed affects how far the curser moves as the mouse moves; i.e. inches vs. inches. Acceleration affects how fast the cursor moves as the mouse moves; linear speed vs. inches. That is, having tracking low and acceleration high means that when you are trying to hit the close button and are moving the mouse slowly, the cursor barely moves, but when you want to move all the way to the opposite corner of the screen and move the mouse quickly, the curse moves rapidly to the corner.

This does not do that. No matter what speed you move the mouse the mouse tracks at the same rate. Now, as I understand it, this is a limitation introduced with Snow Leopard by Apple – they removed the API for acceleration. But I was hoping that this app had introduced their own implementation for mouse acceleration. Not so.

Half way there

This app does a great job turning off acceleration and has a clean interface. The only problem, as others have said, is that mouse settings seem to be either/or. Either you control mouse acceleration or you control mouse tracking speeds. I find that turning off acceleration at least makes the mouse usable, but the tracking speed is too slow and not configurable. If I go into the OS settings for the mouse to adjust the tracking speed, then the acceleration comes back on. In order of priority, support for the following would make this app 5 stars: (1) Tracking Speed control, (2) Ability to disable Scrolling Speed acceleration (my mouse wheel suffers the same acceleration problem), (3) Scrolling Speed control (assuming implementing #2 would result in the same either/or problem found with Tracking Speed.

Lion OSX - mouse accel issue

After upgrading to Lion & seeing immediate issues with my mouse & keyboard, and finding the typical 0 responses from Steam on their forums (which makes you wonder why they sell games that run on Macs), I found 2 threads on the Apple that were helpful with my mouse issues. However, the mouse accel "fix" seemed to reset after I turned my comp off and once in the middle of a game.

I cannot have this happen during a match so I reread the forums & bought this. Totally worth $0.99 BUT I have 1 minor issue: The speed that I'm used to seems to be between the Decelerator's settings of 0.5 and 1.0 So I will have to adjust my game, which is awful b/c the season starts in ~ 10 days. So if it was more adjustable, it'd be perfect & I'd give it 5 stars.

View in Mac App Store
  • $0.99
  • Category: Utilities
  • Released:
  • Version: 1.0
  • Size: 0.4 MB
  • Language: English
  • Seller:

Compatibility: OS X 10.6 or later

Customer Ratings

Current Version: