SkyDrive Smart Files in Windows 8.1 & how to Hydrate them

The SkyDrive team recently announced about the SkyDrive Smart files in Windows 8.1. In this post we will see more details about these Smart files of SkyDrive in Windows 8.1. Earlier these were referred to as Placeholder files.

Smart Files are one of the coolest features built into Windows 8.1 SkyDrive. In today’s world more and more people are taking more pictures, videos, storing them and documents, data, etc on their devices. Moreover, people are using all kinds of devices including smaller devices, which also want to access these growing data sets, which are  getting stored on cloud storage like SkyDrive. So the challenge which arises is how to accommodate these huge amount of SkyDrive data on smaller devices. There may be some, who do not want everything from SkyDrive to be downloaded on to their devices, when synced.

SkyDrive Smart Files in Windows 8.1

Let us say that you are accessing your 200GB SkyDrive account (Yes, SkyDrive recently introduced a new storage option to add 200 GB of additional storage) on your Smartphone or say a low-end Tablet with less storage. In earlier versions of Windows , that is Windows 8 and earlier, you were able to choose which folders you wanted to see and which you did not, using Selective Sync. Those not chosen, were not available. But with Smart Files that’s not the case, you can see everything you have – even when your SkyDrive content is much bigger than your storage space, and you can decide what you want fully accessible, when your computer is offline.

So what Smart Files does is that, instead of syncing all the files & folders, it syncs the metadata of the files and their hierarchy, to know where they exist in the tree. So this way, we know about the files as their tree structure, even when we are offline. With Windows 8.1, as you can see the SkyDrive folder on the desktop, the full hierarchy of files is seen and they look just like regular files. The SkyDrive Sync Client is directly built-in the Windows 8.1.


If you look at them they look like regular files in File Explorer, as if everything is available. But if you see their Properties, the size of SkyDrive in this example is 153MB while Size on disk shown is 32MB. All this is due to syncing of just the metadata, which are very small bits of data.


What is Hydrating? How to know which files are Available offline?

So what happens if you double-click one of these Desktop SkyDrive files? Here for a text file, you can see its available status saying ‘Online-Only’.


Double-clicking it will open the file, downloading it automatically. SkyDrive team’s Adam Czeisler in this video explaining it, calls this process Hydrating a file and the availability changes to ‘Available offline’. This assures that you can access it even, when you are not connected to the net.


To know which SkyDrive files are available offline on your device, the only way to know this is to change the Explorer View to Details view which adds the ‘Availability’ column.

Smart File experience for images

Photos are one of the most popular storages on SkyDrive. Let us check the Photos experience in SkyDrive. Its little bit different. As you know, we can interact with SkyDrive files in 2 ways – using modern SkyDrive app or using File Explorer, as we have seen earlier, showing Smart Files just like regular file system.

If you access SkyDrive using modern SkyDrive app, you can see a touch kind of UI, that shows the SkyDrive content. Checking any Photos folder, you can see them all as thumbnails. When you view a SkyDrive stored photo by double clicking, it opens in the SkyDrive app. You can view them using the ‘Open with..’ option too, by right clicking and using app bar option. When the photos are viewed in SkyDrive app, Photos app or Windows Photo Viewer, it is not the full resolution download, but instead a full-screen representation is downloaded which is much lighter.

This means that a much smaller network bandwidth is consumed. So one can even see a 1600 x 1600 pixel ‘thumbnail’ image – but remember, they all are not actual photo images. On a low powered device, this is helpful as it does not need to do heavy work to download say, a  big 4 MP photo. What it downloads is exactly what is just needed.

SkyDrive has the capability of tiered thumbnails providing different sizes of thumbnails like 480×480 pixel or 1600 x 1600 pixels – and these are baked right into the shell. However big the photos may be, you will see their thumbnails quickly.


But when you want to edit and click edit, you will be able to see a Loading… sign being displayed, as it then starts to download the actual full resolution image. The image then gets ‘hydrated’.


This full resolution hydrated file can then be edited. And just to mention about the editing features, they are the same as available in the Photos App, as the Modern SkyDrive app and the Photos app are built on the same source code. Thus you have full image editing features in the modern SkyDrive app. Once the image is opened for viewing, just right click to get the various editing option.

If you notice you may see a little symbol on the bottom right of the some of the images, it indicates that its available offline and is fully hydrated. So you can make sure the file is offline & fully Hydrated when this symbol is seen and this happens only when you click ‘Edit’.


You can make them available ‘Online only’ again once downloaded by using the option in Photos/SkyDrive App bar as shown below. You can also see the ‘Open with’ option mentioned earlier.


So you can see that Smart Files are really Smart and one of the coolest feature in scaling large SkyDrive storage files even to a small device. If someone with a huge hard disk capacity, wants everything synced to make it available offline, it’ll allow you to sync everything too. Similarly if someone is travelling to a place where the net connectivity is not good, they can also have the required files available offline, so that he can access it without net connectivity during the travel. Later on, one can again make it available online again, just by right clicking on a file.


The Smart Files thus gives users a flexibility, an option to mark any file, folder or the complete SkyDrive as available offline, if you have space to download them. Just right click on any file, folder or SkyDrive to get the option in Explorer.

Smart Files and Search experience

We have seen Smart File syncs metadata of files and their hierarchy, and not the actual file. So when you have these Smart Files, how good is the search experience? Can these files be searched with just bit of metadata?

The SkyDrive team is improving upon the search experience. Not all metadata is extractedbut keywords are one of the properties that is extracted and are syncd down as part of Smart Files. Presently not all photos in SkyDrive have this property extracted and the SkyDrive team is aware of it and is working on it. New photos will have their keywords searchable almost immediately. Even text in Office documents will be extracted and provided as metadata.

So for people who want the SkyDrive data made available across number of devices, it delivers on the promise of ‘Your files always with you’, whatever be the kind of device. It’s the user who decides whether and which data he wants it offline

So if you are using SkyDrive on Windows 8.1, do try out this cool feature of Smart Files.

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The author has been a Microsoft MVP awardee in various Windows categories (2006-2016) and currently a Windows Insider MVP. A Technology Enthusiast, interested in anything technical and is committed to Microsoft technologies and products. He is actively associated with various Microsoft online communities, forums, Newsgroups and has been actively involved in Beta testing various Microsoft products and bug submissions.

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