(AP) -- Moving digital files between your work and home computers can be a pain. Add smartphones and tablet computers to the mix, and you've got yourself a giant headache.
Google Inc. unveiled its solution to the problem last week, while two other companies, Dropbox Inc. and Microsoft Corp., improved their existing offerings. The idea is to leave your files on their computers, so that you can access them from any Internet-connected device, wherever you are.
That means you can stop emailing big files to yourself, and you can stop carrying those USB thumb drives that fill up quickly, especially when transferring photos and video. These services also make it easier to share documents with others.
The three services I tried are free, though you'll have to pay if you need more than your allotted storage.
Google Drive, Dropbox and Microsoft's SkyDrive share many core features.
You can store just about any type of file - photos, videos, songs, spreadsheets and more - on distant servers operated by those companies. All you need is a Web browser and an Internet connection. To upload a file to the online storage service, you simply move the file's icon to the browser window. The original file remains on your computer.
To access a file from another computer, you simply go to the service's website and log in. You can make changes on that computer and move the file back online. You can create Web links to entire folders or specific files for sharing.
You can install free software to simplify these transfers. The software creates a special folder on your computer for that particular service. Anything you add to it will automatically get transferred to your online storage. If you or colleagues make changes from another computer, the original version gets automatically updated.
A subset of features is also available through apps for mobile devices. You can pull up photos and other documents on the go, though it's not designed for making too many changes.
One drawback with all three services: You can lose metadata associated with these files. Attributes such as the file's creation date can change in transfer. The contents aren't affected, with one major exception I'll discuss as I compare the individual services.
The services give you plenty of free space for word processing, spreadsheets and other basics, but not enough for extensive storage of photos and video.
You get 2 gigabytes for free on Dropbox, 5 GB on Google Drive and 7 GB on SkyDrive. Those who used SkyDrive before April 23 can claim 25 GB of free space, though others might be eligible too. Dropbox lets you earn additional free space by recruiting friends or performing such tasks as installing Dropbox's software.
Signing up for additional free accounts gets cumbersome, so count on paying if you need more. An extra 100 GB will cost $50 a year on SkyDrive and $59.88 on Google Drive, while 100 GB including the free space will cost $199 on Dropbox. Cheaper plans with less storage are available.
Winner: SkyDrive, with the most free storage and cheapest upgrade plans.
All three let you share content by creating links.
On Dropbox, friends with that link can view the content, though you'll have to go through extra steps to create a "shared folder" for others to edit documents.
With SkyDrive, you can give people editing capabilities with that link. In fact, you can give some people a view-only link and others a link with editing privileges. You can share via email and decide whether recipients can edit documents. You can also post content to Facebook, Twitter and other social networks directly from SkyDrive.
Google Drive also lets you choose whether links come with editing capabilities. But unlike SkyDrive, you can't create view-only links for some and editing links for others. It's one or the other for particular files and folders. You can also email items as attachments or as a link to your Google Drive account.
Dropbox and SkyDrive can automatically turn the photos you share into galleries, so that friends can view them through an interface that resembles what you'd get on Facebook or a photo-sharing site.
Winner: SkyDrive, with the most options for sharing.
Not surprisingly, the best search options come from Google, the Internet search leader.
Searching on Google Drive is fast and versatile. You can search not just by file name, but also the contents of documents in a variety of popular formats. It uses an optical-character reader to pull out text from newspaper clippings and brochures you scanned. I was impressed that it found multiple references to "cockatoo" embedded in some scanned brochures.
Dropbox searches based on file names only. SkyDrive searches contents of documents in Microsoft formats - Word, PowerPoint and Excel - but it won't even index the file names for other types, including photos.
Winner: Google Drive
Dropbox has the most software options.
For desktops, there's a Linux version besides ones for Windows and Mac computers. Microsoft and Google support Windows and Macs only. Microsoft's software won't work on Windows XP, an older, but still widely used system. It also won't work on earlier versions of XP's successor, Vista. So many SkyDrive users will be stuck with the Web-based interface.
Dropbox also is the only service to offer phone apps for both Apple and Android devices. It's also the only one to support BlackBerrys. Google doesn't have a version for iPhones or iPads yet; its app only works on Google's Android system. Microsoft doesn't make one for Android, though it has one for its own Windows Phone system besides the Apple devices.
- And the rest ...
Dropbox has a handy feature for restoring files you accidentally deleted or overwrote. That means you can go back to an earlier draft of a document if you change your mind - up to 30 days, or forever if you have a paid account. For truly sensitive files, a few extra steps are needed to permanently erase them.
SkyDrive will automatically shrink larger photos to save space if you use its Web interface, unless you notice and uncheck a small box. Some people may like that, as it'll speed up file transfers. But if I had deleted my originals before noticing that, I could have lost them forever. I didn't get any warnings ahead of time. That's enough for me to lose confidence in the service.
Google Drive offers to convert files to Google's online documents format. That makes it easier for multiple people to collaborate. When you make changes to a spreadsheet from your computer or phone, it will pop up seconds later on all the other screens where it's open. Collaborating through Dropbox and SkyDrive gets clunky. As a bonus, files in Google formats don't count toward the storage quota.
One annoying thing about Google: Under standard settings, if you upload the same file three times, it will get stored as three separate files on Google Drive - all with the same name. It ought to just replace the file - after asking, of course - and perhaps keep an older version hidden away as Dropbox does.
SkyDrive wins on storage and sharing, but it ought to be more forthcoming about shrinking originals.
Google's nifty search features make it the best choice overall. After all, storage does little good if you can't find what you need.
If you aren't bothered by that, Google Drive is the service you'll want. Otherwise, Dropbox is a fine alternative, especially if you expect to use it a lot on a variety of phones or an iPad.
Whatever you choose, I recommend that you keep your original files somewhere, even if you have to buy an external storage drive. These services are good for backups and sharing, but what SkyDrive did to my photos made me realize they are all too new to fully trust.
Anick Jesdanun, deputy technology editor for The Associated Press, can be reached at njesdanun(at)ap.org.
Google Drive: http://drive.google.com
Explore further: Neil Young unveils high-definition music player, store