Skip to main content
Skip to main content
Microsoft 365

Have all your SkyDrive files with you – without using all your storage or bandwidth

This is an exciting time to be in the cloud-storage business. Industry trends suggest that even though devices have larger storage capacities (growing 25% per year), people’s data and files are growing significantly faster (around 50% per year).


This is especially true for mobile devices. Windows is used by a billion people across the world and with SkyDrive, our goal is to design cloud storage at the same scale so people can have their files with them on any of their devices.


With Windows 8.1, we’ve taken a big step towards that goal. SkyDrive is deeply integrated into Windows. Opening and saving files to SkyDrive is now as easy as saving to your hard drive, but with SkyDrive, your files are also available to you on your phone, tablet, desktop PC, and via In addition to the basics, we’ve come up with some creative and unique ways to address the needs of the increasing number of people who have tons of files but relatively small device hard drives.


All your files with you

Because people’s data storage needs will continue to grow faster than storage capacity on their mobile devices, we asked ourselves how we could provide you with access to all your SkyDrive files without actually downloading them, using precious local disk space and Internet bandwidth. Our answer is what we often refer to as “placeholder files.” Placeholder files look and feel like normal folders and files. You can tap or click a folder and see all the folders and files inside it. You can tap or click a file and it will open, you can edit it and close it. You can move, delete, copy, or rename placeholder files just like you would any folder or file. But we only download the full file when you access it. What we have in its place is a placeholder file containing a thumbnail image along with some basic properties and file content. This means that the placeholder file is significantly smaller in size that the file in SkyDrive, but when you need to use it, we’ll download the full file for you.


For example, in the image below, I have a Pictures folder in SkyDrive that’s 5.6GB in size but it’s only taking up 185MB on the local disk.




For photos, flipping through lots of pictures in one go is a common scenario. We wanted to give you fast scrolling of photos without taking up a lot of local disk space. So we’re doing something even more special there. When you flip through photos, we download large thumbnail images instead of the actual files. And we pre-fetch thumbnails to enable fast scrolling. It’s only when you want to edit a photo that we download the full file to the local disk.


Combined, placeholder files and smart thumbnails allow you to see and interact with your entire SkyDrive without taking up much local disk space and only using your Internet connection when needed. Early data in the weeks since Windows 8.1 Preview was released suggests that this architecture is delivering on the goals we set out with and SkyDrive files are taking up less than 5% of the local disk space that they would have taken in the old system.


So to put a fine point on that, using placeholder files, someone who has 100GB of files in SkyDrive that have been built up across many devices and years, can now have all of those files available on their new Windows 8.1 device and will be using less than 5GB of storage for all those files on their local hard drive.


Providing access to all your files on devices of every size and shape helps ensure that you don’t have to make tough decisions about what subset of your SkyDrive files you want available, and provides complete cloud access that isn’t offered by anyone else.


Offline access

One of the biggest investments we’ve made for Windows 8.1 is a seamless experience across connectivity states. So, if you’re on the go and want the documents you’re working on to be there when you lose Internet connectivity, and you want all your edits to make their way back up to SkyDrive when you get connected, we do just that without any need for manual configuration and setup.


With the SkyDrive app, you’ll be able to mark any folders or files you want for offline access. Edits on this device or another device will be synchronized so that you’re always working with the latest file. This is an explicit, easy-to-understand way to have guaranteed offline access to the files you most care about.




When you’re offline, it’s easy to tell which files are available for offline access.




In order to make things even more convenient, we always mark files for offline access if you’ve opened or edited them on this device before. We do that because most people tend to open the same files they recently opened, but the files they open often vary across different devices – so we remember those files and make this unique to the device you’re using. And of course, you can also choose to mark any individual file or folder for offline access – and of course, if you’re working on a device with a lot of local storage, you can choose to have your entire SkyDrive available for offline access.




Opening, saving, and searching files

Any Windows Store app can use the Windows file picker to let you open, edit, and save any kind of file. In Windows 8.1, SkyDrive is built into the file picker – so every Windows Store app can save files directly to SkyDrive without any extra work. And the files will quietly get uploaded in the background so you don’t have to wait around. For example, if someone shares pictures with you in an email, you can save them to SkyDrive from the Mail app.


And you don’t have to worry if you happen to be offline when you save the file. We’ll just save it locally and upload it to SkyDrive when you do get connected.






If you were working in a desktop app, you get the same functionality using the Windows common file dialog – opening and saving to SkyDrive is as easy as saving to your PC.




And of course, SkyDrive shows up in the desktop File Explorer for all Windows 8.1 users (as long as you’ve signed in to Windows with a Microsoft account). You can drag folders and files from your PC or any other attached device to SkyDrive. If you turn off your device before everything gets uploaded, we’ll just resume uploading the next time you’re online.




Many people use search to quickly access their files. So we’ve made search work just as you’d expect – SkyDrive files show up in search results just like your local files. For example, if you have a document in your SkyDrive, we extract a few lines of text from the document and provide that to the search indexer on your device so that it can return search results that are more relevant to you. It goes without saying that search works across your entire SkyDrive (including placeholder files). In the example below, “Alyssa’s birthday bash” and “Mom’s birthday cake” are both documents in SkyDrive that exist as placeholder files on the local device and are searchable whether you’re online or offline.







In the weeks since Build 2013, we’ve seen great adoption of SkyDrive in Windows 8.1 Preview. As we mentioned, we’re excited to see that people are getting access to their huge collections of files while only taking up local storage that’s less than 5% of their total file size. And in just the first week after Build, we saw over 3TB of data uploaded to SkyDrive per day from those devices running Windows 8.1 Preview. We’ve also gotten feedback on what else you’d like to see in the product, and we’re working hard to address that feedback in the upcoming milestones. We look forward to hearing more of your suggestions and comments here on the blog and in the Windows 8.1 Preview forum.


– Mona Akmal, Group Program Manager, SkyDrive apps


Editor’s note, 9/27/2013: What we refer to as “placeholder files” in this blog post are now called “smart files”.


You may also like these articles

Image for: Logo for the "Rise of the IT leader" infographic, with an arrow pointing upward.

The rise of the IT leader

Gain insights to help you become an IT leader.

Image for: Featured image displays two employees holding documents, engaged in a meeting.

Collaboration hacks from real-life teams

Download the new eBook, “Collaboration hacks from real-life teams,” to learn how companies have reinvented their workplace culture to compete in an information-intensive, interconnected world, where innovation happens in real-time, around the clock and across time zones and geographies.

Image for: Image shows a collage featuring a man checking his email from a mobile device, another contemplating an email and the letters "IT."

3 ways to outsmart shadow IT

Download our new infographic to learn how IT can help the business before business users help themselves.