Microsoft finally revealed its long-awaited and oft-leaked Windows Phone 8.1 update at the Build 2014 conference on Wednesday. Don’t let the measly “.1” fool you: Windows Phone 8.1 is a sweeping refocusing of the Windows Phone vision, adding some much-needed features to the mobile operating system—including the grand unveiling of Cortana, Microsoft’s new digital assistant.

Joe Belfiore shows off Windows Phone 8.1 at Build 2014.
Microsoft exec Joe Belfiore took the stage to show off the improvements, declaring that “We believe Windows Phone is the world’s most personal smartphone.”
Action Center
As previously leaked, Windows Phone 8.1 adds a long-awaited notification center—dubbed “Action Center”—which gathers your new messages in a central location and provides quick access to four basic phone functions, such as turning on Wi-Fi, GPS, or Airplane mode. Those quick-access tools are customizable and can be swapped around as needed. If you have a dual-SIM phone, info about each is available in the Action Center.
The Action Center should be a massive improvement to Windows Phone’s usability. Live Tiles are nice and all, but it’s even nicer to have all your new notifications in one convenient spot, and nobody likes mucking around in their phone settings any more than they absolutely have to.
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Developers will also be able to create custom lock-screen experiences that users can choose to use. The Windows Phone 8.1 update also adds new Start screen personalization options, including the ability to add more tiles to the screen or use a custom image as your phone’s background image.
Cortana
But the real star of the Windows Phone 8.1 show is Cortana, the virtual assistant that’s Microsoft’s answer to Google Now and Siri. Actually, Cortana’s kind of a blend of Google Now and Siri—a bouncy, bubbly sphere UI that’s powered by Bing’s deep and powerful Satori knowledge engine.
Cortana has a Siri-esque personality, responding to personal questions from Belfiore with jokes. For example, when Belfiore asked what Cortana thought of her appearance, she responded “Some things I resemble: A hula hoop, a donut… and a halo.” (The last is a sly reference to Cortana’s origins; she’s named after the Cortana A.I. central to the popular Halo video game series.)
Cortana’s true strength appears to lie in context, however.

Cortana will be a smarter personal assistant by gathering data from third-party services to inform her responses.
“Her” smarts are augmented by data provided by third-party services such as Yelp, which Belfiore showed off by searching for a restaurant during the demo, as well as contextual information about you—yes, you—drawn from your email, travel notifications, contacts, interests, and more. Even better, you don’t have to manually tell Cortana your desires; she automatically infers information based on your actions (which you then have to confirm).
The added info is designed to give Cortana a more personal touch and provide contextual, “just-in-time” notifications a la Google Now. But fear not, privacy freaks: The digital assistant has a granular and customizable “Notebook” that allows you to block or grant Cortana access to specific information silos and functions.
Cortana responds to natural-language commands, and the mixture of deep data and personal information allows her to perform Google Now-esque tasks, such as finding nearby restaurants, finding and converting information on the Internet, or scheduling alarms and reminders, all using natural language.

Cortana can juggle reminders and appointments and alert you to conflicts.
In fact, Cortana’s smart enough to know if a newly scheduled reminder conflicts with a previous appointment, notifying you of concerns and offering to reschedule something if necessary. Microsoft’s also allowing developers to access Cortana’s voice commands. Belfiore used Cortana to verbally add a show to his Hulu Plus cue and open up Terry Myerson’s Facebook page on stage.
Cortana’s launching as a beta in the US before eventually expanding to UK, Canada, China, and beyond in the coming months. Between that and the Action Center, Windows Phone 8.1 is starting to look mighty tempting… but there are still more new features coming to Microsoft’s mobile OS.
Not just for fun
Microsoft also revealed that the similarly long-awaited Windows Phone Enterprise Feature Pack—which adds business-friendly tools like S/MIME support, enhanced MDM policies, and application-triggered VPN support (or application-specific blocking—is coming with Windows Phone 8.1.
Internet Explorer 11
Windows Phone 8.1 also upgrades the browser to Internet Explorer 11, complete with Reading View, InPrivate tabs, and so on.
Other tweaks
The Windows Phone store also received a revamp, with featured apps and the ability to sweep left-to-right for quick navigation. Windows Phone’s calendar received a similar tweak for moving from day-to-day.

Windows Phone 8.1 will use what it knows about you and your contacts to make typing more context-aware and faster to guess or auto-correct.
Belfiore also walked through a new “Wi-Fi Sense” tool, which you can configure to automatically connect to free Wi-Fi hotspots. The tool can automatically agree to a hotspot’s terms of service for you if you’d like, or even provide the hotspot with your name and personal information if it’s required (and you agree to it). Seems pretty darned nifty! Windows Phone 8.1 boasts additional helpful tools such as Battery Sense, Belfiore said.
The Windows Phone keyboard was also enhanced with Swype-like fast typing capabilities.
Hardware changes
Windows Phone 8.1 is also receiving some hardware support tweaks that Belfiore didn’t really mention at Build on Wednesday, but he detailed at Mobile World Congress in February. When he did so, Belfiore stressed that the stated goal for Windows Phone in 2014 was to find traction beyond U.S. soil, as foreign markets have been a strong point for Microsoft’s mobile growth.
That target reads loud and clear in Windows Phone 8.1’s hardware tweaks.
The update adds support for Qualcomm’s low-end Snapdragon 200, 400, and 400 LTE system-on-chips as well as numerous additional cellular standards, to better support Microsoft’s “high-volume focus” around the globe. (Read: Cheap phones.) Continuing that thought, Windows Phone 8.1 also removes the requirements for hardware buttons, letting manufacturers opt to use virtual softkeys in Android-esque fashion—which would let those manufacturers more easily reuse the same hardware for Android phones and Windows Phones alike.
Windows Phone 8.1 also adds dual-SIM support, which is a popular feature in foreign markets, as Nokia’s Stephen Elop noted when introducing his company’s new phones at Build.
All in all, Windows Phone 8.1 looks pretty darned exciting, and the introduction of universal apps that span the Microsoft ecosystem should hopefully help bolster the Windows Phone Store’s (rapidly improving) ranks. Look for Windows Phone 8.1 to start rolling out to current Windows Phone 8 users “in the next few months,” or in new phones by the end of April or early May.
Updated to add Windows Phone hardware details.