It was released on October 29, 2012, and, like its predecessor, it features a flat user interface based on the Metro design language.

Windows Phone 8 also allows devices with larger screens (the four confirmed sizes are "WVGA 800×480 15:9","WXGA 1280×768 15:9","720p 1280×720 16:9","1080p 1920x1080 16:9" resolutions) and multi-core processors, NFC (that can primarily be used to share content and perform payments), backwards compatibility with Windows Phone 7 apps, improved support for removable storage (that now functions more similarly to how such storage is handled on Windows and Android), a redesigned home screen incorporating resizable tiles across the entire screen, a new Wallet hub (to integrate NFC payments, coupon websites such as Groupon, and loyalty cards), and "first-class" integration of VoIP applications into the core functions of the OS.

Additionally, Windows Phone 8 includes more features aimed at the enterprise market, such as device management, BitLocker encryption, and the ability to create a private Marketplace to distribute apps to employees[7][8]—features meeting or exceeding the enterprise capabilities of the previous Windows Mobile platform.

Microsoft pushed support up to 36 months, announcing that updates for the Windows Phone 8 operating system would be made available through January 12, 2016.

Due to the switch to the NT kernel, Windows Phone 8 also supports native 128-bit Bitlocker encryption and Secure Boot.

[17] The UEFI with ACPI protocol was adopted as boot loader of Windows Phone 8, as part of its board support package.

Internet Explorer 10 is the default browser in Windows Phone 8 and carries over key improvements also found in the desktop version.

Unlike its predecessor, Windows Phone 8 uses true multitasking, allowing developers to create apps that can run in the background and resume instantly.

[18] A user can switch between "active" tasks by pressing and holding the Back button, but any application listed may be suspended or terminated[19] under certain conditions, such as a network connection being established or battery power running low.

When Kids Corner is activated, apps and games installed on the device can be played or accessed without touching the data of the main user signed into the Windows Phone.

[29] The Verge gave the OS a 7.9/10 rating, stating that "Redmond is presenting one of the most compelling ecosystem stories in the business right now," but criticized the lack of a unified notifications center.

[30] Alexandra Chang of Wired gave Windows Phone 8 an 8/10, noting improvement in features previously lacking in Windows Phone 7, such as multi-core processor support, faster Internet browsing, and the switch from Bing Maps to Nokia Maps, but also criticized the smaller selection of apps.

[32] Roughly a year after the release of WP8, Kantar reported in October 2013 that Windows Phone grew its market share substantially to 4.8% in the United States and 10.2% in Europe.