Google finally unveiled its long-rumored Pixel smartphones earlier this week. They will be the first to launch with Android 7.1 Nougat, but many of the Pixels' best features, such as the new Google Assistant, won't appear on other Android devices, including Google's own Nexus series, when the OS arrives.

An Android 7.1 Nougat changelog leaked to Android Police shows which new features will appear in the upcoming operating system, as well as those that are Pixel-only. Google confirmed that the information is accurate is to TechCrunch.

The absence of the AI-powered helper will come as disappointment to those who expected to see the Siri/Cortana/Alexa rival on every handset receiving Android 7.1 Nougat. Google Assistant is essentially a more advanced version of Google Now, able to engage in two-way conversations with users, perform complex tasks, and learn and recall personal information from previous conversations for context.

Other Pixel exclusives include the free, unlimited photo and video (in their original quality) cloud backup service; the smart storage feature, which automatically removes old, backed up images/videos when the storage is full; and the Pixel Camera and Launcher apps. 24-hour phone/chat support and screen-share functionality will also be limited to the Pixel phones.

There are some interesting new features coming to all devices that receive Android 7.1, though. There's the Night Light blue filter, which changes the color temperature of a display at night. A Daydream VR mode is also on its way, along with support for sliding down on the fingerprint sensor to open the notification bar.

Google did say that its Assistant would eventually be arriving on other Android devices, just don't expect it soon. Ultimately, the company will likely replace Google Now with its more advanced version of the assistant.

"Our goal is to make the Google Assistant widely available to users, and we'll continue to launch new surfaces over the course of the next year," a Google spokesperson told TechCrunch.

The developer preview of Android 7.1 arrives later this month. Google hasn't said when it will come to phones other than the Pixel.