With the cost of SSDs (solid state devices) plummeting, you might be tempted to replace your current drive with a faster, quieter version. As large capacity SSDs still command a substantial premium, you may opt for a smaller hard drive than your existing one; 240GB will set you back around £170 while 1TB is around three times as expensive. Don’t forget that Mac OS X requires about ten per cent free hard drive space in order to maintain its files. Time for a clear out!

Where’s the space gone on my Mac?

Before relocating or getting rid of data, find out what’s hogging your disk space. GrandPerspective (free) and DaisyDisk (£6.54) give good visual indications while OmniDiskSweeper (free) uses the standard hierarchical file window to show the sizes of every file and folder. Other apps such as CleanMyMac 2 (£34.95) show disk usage as part of their cleanup features.

Fast space finding fixes

Now you know where your space has gone, time to make some quick kills. Start with your downloads folder. Finished installing downloaded apps? Then bin the dmg file or installation package. How about all the mp3 music files? As you drag each file into iTunes it makes a copy. If you hit command-shift-R within iTunes you can see the current location of this. Get rid of the originals.

Empty the Trash frequently. If there are any stubborn files that won’t disappear, the easiest solution is to use Trash It! (free), a useful one-trick pony. 

How about your Mail attachments folder? Think about how many emails you receive with large attachments. What happens to these? Within the main Mail folder (~/Library/Mail), attachments for incoming mail are stored in the inbox folder. To make sure those from deleted emails are removed, go to “Remove unedited downloads” in Mail’s preferences and select “After Message is Deleted”. The current version of Mail also stores attachments in ~/Library/Containers/com.apple.mail/Data/Mail Downloads. As long as you don’t need them these can also be deleted, often saving you many hundreds of MB. 

If you own an iOS device, chances are you’ve downloaded and tried numerous free apps before deciding not to use them long-term. Even though they’re no longer on your device, they still reside on your Mac at ~/Music/iTunes/iTunes Media/Mobile Applications. Some apps are huge, especially games and offline/GPS maps, with individual apps having an official ceiling of 2GB. Clear out this folder to save space big time! 

If you work with iMovie you’ll be aware that video consumes huge amounts of hard drive space. Five minutes of video takes up approximately 1GB and editing a large movie will quickly use up your disk space. You can delete unused clips by selecting them and pressing the Delete key or by dragging them to the iMovie trash which also contains excess footage trimmed off clips and other items deleted from your project. The key here is to empty the trash, so permanently deleting such files from your project. Do bear in mind that you will not be able to undo any previous changes or retrieve clips.

Any sort of shared folder has the possibility of increasing in size if it is not pruned regularly. Top of the list will be those set by the system’s file sharing preferences. But the real culprit is likely to be Dropbox or any similar commercial sharing app. Offering many GB of file storage free of charge, Dropbox creates a duplicate folder in your home root directory. Every time someone adds files to a shared folder, these files are synced into the folder on your Mac. As this folder behaves like a standard Mac folder, whenever you move a file out of Dropbox it may also be deleted from the online shared folder depending on your settings. Consequently many users copy files out of Dropbox and end up with duplicates on their Mac so exacerbating the storage situation. Try to control all deletions and permanent deletions from the Dropbox website.

What else can I get rid of?

First, a warning. From Mac OS X 10.7 onwards, Apple has hidden the user-level Library folder. Prior to that, it could be found at ~/Library. There’s a very good reason for this: as this folder contains files used by your apps along with fonts and preferences, deleting items here can be very risky. While accessing this folder is quite straight forward, think carefully before manually deleting any files from here.

When uninstalling apps, don’t forget the support files. For instance, the GarageBand app is about 160MB but the support files (sounds, audio files, etc) can take up many GB. You can find this at /Library/Application Support/GarageBand. Any app that can help you run Windows software such as Parallels or VMware creates separate virtual machines for each Windows OS. If you have more than one do you need them all? For instance, a Windows 8 virtual machine in Parallels weighs in at over 14GB. Even CrossOver, which runs a limited number of Windows apps without installing the OS, creates ‘bottles’ for each app: the Microsoft Office 2010 one is upwards of 2.5GB.

Generally you can delete any files or folders you have created including those within your downloads and documents folders. 

But I really need to keep everything!

If you really are the proverbial data squirrel, here are a few simple suggestions:

• Archive any files you are unlikely to need regularly. Control-click on a folder and select the compress option. The space saved will vary according to the type of file being archived: JPEGs and DMGs, for instance, are unlikely to compress very much. Once created, archives can either remain on your Mac or be saved to an external drive.

• Use an external drive for data files. This would be especially useful for design, audio or video files.

• Migrate your iTunes Music folder to an external drive and then relink to this within iTunes. This is quite possibly the single largest folder on your Mac: mine is a disk-busting 25GB.

Finally, if you do take the decision to delete files or folders, always back them up first. You never know…

Get rid of unwanted apps

It’s amazing how many apps you can acquire over a short period of time let alone over the many years most of us have been using a Mac. Most Mac OS X apps are bundles. The application is usually a special folder that looks like a single, double-clickable file and contains almost all the files needed to run the app. Trashing the app is easy; getting rid of all the support files isn’t. There are preferences (plist) and application support files and these can exist in a number of places on your Mac. These files along with the app itself may be wasting many gigabytes of your hard drive space.

Some major apps include an uninstaller. For example, you’ll find one of these in the Additional Tools folder of Microsoft Office. Sometimes an app’s installer doubles as an uninstaller. But the lack of a dedicated uninstaller in Mac OS X is a serious omission.

Fortunately there are a number of third party options. AppCleaner (free, www.freemacsoft.net), AppDelete ($7.99, www.reggieashworth.com) and AppZapper ($12.95, www.appzapper.com) all do the same job – but the fact that they each find different files to remove shows how complicated a process uninstalling can be!

AppDelete, AppZapper and AppCleaner all find different files when uninstalling! 

Too many languages and old code

Mac OS X supports a range of world languages, being localised for over 25 languages all of which are included automatically during installation. Using Mountain Lion’s Language & Text (previously International) system preference, languages can be put into preferred order making it easy to switch between them. Many major applications support multiple languages too, using the order from Language & Text to select one if the app doesn’t support your main language. The problem is that if you only want to use one or two languages, Mac OS X and many of your apps are bloated with all the others.

Getting rid of unwanted code is another disk-saving exercise. Universal Binaries host both PowerPC and Intel architectures yet since Lion, the former is not supported. 

Monolingual (donation requested, monolingual.sourceforge.net) lets you remove specific architectures from Mac OS X along with specific languages. While it can claw back huge swathes of hard drive space, unless you’re careful with the preferences it can also render your Mac unbootable so use with extreme care. 

Xslimmer ($14.95, www.xslimmer.com) works on an app level, keeping only the languages you select. Again, care is required as some apps view the removal of code as being an attempt at circumventing copy protection. To that end, Xslimmer keeps an updated blacklist of apps to be left alone.

Get rid of old code and unwanted languages with Xslimmer

Bye bye duplicates

How much of your precious hard drive space is being taken up by duplicate files? While hard drives may be getting bigger and cheaper, Apple’s direction is that of smaller, faster SSD drives. The problem is that these have smaller capacities so a higher level of filing discipline is essential. 

There are a number of reasons why you end up with so many dupe files. When you add songs to iTunes, if you have ‘Copy files to iTunes Media folder when adding to library’ checked in the preferences, you keep the original. Instant duplication. A couple of thousand high quality songs and that’s anything up to 10GB hard drive space wasted. And that doesn’t include dupes within iTunes. For the latter, iTunify ($15, www.satsumac.com) can help.

The same thing can happen when uploading photos into iPhoto. If you don’t delete the originals from the camera, you could end up uploading them a second or third time resulting in a larger iPhoto library file. Duplicate Annihilator ($7.95, brattoo.com/propaganda) breezes through this.

If you use Apple Mail, remember that all attachments reside in Mail’s own download folder. This can be another source of duplication. 

More generic apps use various strategies and criteria to find duplicates and give you control over which ones to get rid of. Have a look at Tidy Up ($39, www.hyperbolicsoftware.com) or Singlemizer ($9.99, singlemizerapp.com).

Tidy Up makes short work of finding duplications on your hard drive