Xslimmer? What is it?

Xslimmer is a tool for Mac OS X that reduces the space claimed by Universal Binary applications, and their language localizations, on your hard disk, while preserving their full functionality. This is achieved by removing the code inside the Universal Binaries that does not fit with your machine's architecture or your system preferences language selection.

How does it work?

Universal Binaries are often referred to by developers as "fat binaries", and that's for a reason. When a Universal Binary application is created, it contains several versions of the code: a version intended to run on PowerPC machines (like G4 or G5 Macs), another one meant for the more recent Intel machines. This ensures that the application will run on all the platforms that support Mac OS X, but the code that is not suitable for the computer you are using will never be executed, although it is taking up space in your hard drive. Xslimmer analyzes the applications you have installed and removes the unnecessary code, leaving only the most suitable version for the computer you are using, and thus reducing the space taken up on your disk.

Isn't it dangerous to modify the binary data of applications?

Removing code that will never be run on your machine is safe. However, a very small number of applications may not function properly after they have been slimmed down, because they may check themselves to enforce anti-piracy measures. Xslimmer takes a number of precautions to avoid putting you in a position where an application cannot be used after being slimmed down. It provides a backup mechanism that can be enabled from Xslimmer's Preferences, automatically storing a copy of the applications before they are slimmed down. It also provides the means to "blacklist" applications that you don't want ever to slim down. The blacklist is automatically configured to ignore some popular applications known to perform integrity checks on themselves.

We recommend that you enable the backup option if you intend to reduce the size of an application that you will not be able to reinstall.

How much space will I save?

Xslimmer only reduces the size taken up by application code. Other application files, such as icons, images or support files are unaffected. The ratio of code to the total size of the application is very much dependent upon the nature of the application itself. Media-intensive applications, for example, show a lower rate of compression than those based on computing horsepower alone. BBEdit, for example, is reduced by 35%, whereas the reduction in Keynote is very low due to the huge amount of media files in the installation.

The size of Universal Binary code will probably grow in future months, as new architectures are introduced. 64-bit Intel microprocessors, for example, may require a third version of the code to be bundled inside Universal Binaries.

How do I reduce the size of an application, then?

When Xslimmer starts, it will open a window like the one shown in the image to the right. Drag an application, a group of applications or a folder with applications in it and drop them onto Xslimmer. Xslimmer will open the applications list and show you application information, then, simply press the Slim button. That's it!

Wouldn't it be better to just install applications already slimmed down?

Sure. Xslimmer provides a nice little feature that makes it a bit easier for people that install tools frequently. If an application is dropped from a read-only volume, such as a DVD or a dmg file, Xslimmer will install it to your Applications folder and then slim it down immediately. If you are the nonconformist type, you can configure the destination folder through Xslimmer's Preferences.

Is there a way to sort or take out non-slimmable apps from the list?

Press the "Clear" button in the toolbar of Xslimmer. All non-slimmable apps will be taken out of the list, including those just slimmed.

How do I restore an application?

To restore an application from Xslimmer's backup, you need to open the Slim History window (clicking the History button in the main toolbar), then click the restore icon (circular arrow) for the row corresponding to the app you wish to recover.

An application is not working after being slimmed. How do I report it?

To report an application, you should click the "History" button in the toolbar to open a window that will show the list of applications you have slimmed down. Then, you can click on the "report icon" (exclamation mark) for the application, and this will open the "blacklist report" dialog. If you accept to send it, details about the application and about your machine will be sent to us. We will analyze this data to try to understand what is causing the problems you describe, and blacklist the application if necessary.

Application X and tool Y perform other optimizations. Are they available in Xslimmer?

Initially, we did focus on Universal Binary reduction. In version 1.2 we included the ability to remove unwanted language files and localizations. Version 1.5 added full Leopard compatibility. Further optimizations are planned for future versions, with the driving goal remaining to be achieving size reduction without compromising functionality.

What payment methods are available?

Payment services are handled by FastSpring; thus, Xslimmer is available using any of the many payment alternatives they support: a variety of credit cards, PayPal, money orders, checks and others, depending on your location.

When will I receive my license?

Most payment methods are processed immediately after your purchase. These include credit card or paypal balance. In the case e-check, it normally takes 4 days to get processed and confirmed by Paypal. Your license is generated and sent to you via email immediately after paypal signals us that payment has been received. In the case you did not use e-check, and if you have not received your license after a few minutes, please check your spam folder. If you still have not received it, you can use the contact form in order to request it to us. Please do provide an alternative email address apart from the one you used in Paypal, as sometimes email providers have too strong anti-spam measures and they do not allow for our emails to get through.

What does the license give rights to?

There are 2 types of licenses, full and promotional. Full licenses grant the right to use Xslimmer and get free upgrades for the major version current at the time of purchase. Full licenses bought before November 29th, 2007, are valid for any version of Xslimmer due to Xslimmer's first year promotion.

Promotional licenses, like those from MacAppADay, are normally locked to the version of Xslimmer that was available at the time of the promotion.

Based on the usage you give to the license you can install it in a different number of computers:
  • Personal use: A license can be used on all computers owned by the license owner or where the license owner is the primary user.
  • Professional use: A license is required for each user, even when the license owner owns all the computers.

I have lost my license file. How do I recover it?

We can resend you the license. Simply use the following link: License Recovery to recover it. Our automated system should send it right away. Should you not receive it in a few minutes, please contact us.

I have the license, but Xslimmer does not recognize it

Xslimmer recognizes the file only if it has the complete extension, .xslimmer_license. Some email programs do shorten attachment filenames. When this happens, as the extension name is incomplete, Xslimmer ignores the file. Simply ensure that your license file has its full name: "YourName.xslimmer_license".

I want to try it.

Excellent. Please, grab your copy from the main page.

I need to report a bug.

Too bad you found one. Use our feedback form to contact us. Your bug is important to us and the information will help other users.

Which languages is Xslimmer available in?

As of this moment Xslimmer is localized in English, French, Italian, Spanish, Japanese and Dutch.