How does Twitter determine which devices are associated with my account or device?

When you log in to Twitter on a browser or device, we associate that  browser or device with your Twitter account. Whether or not you are logged in to Twitter, we may also receive information about your browsers or devices when, for example, that information is shared by a partner; you visit twitter.com; you visit third-party websites that integrate Twitter content; or you visit a Twitter advertiser’s website or mobile application. We may use this information, most commonly IP addresses and the time at which the information was received, to infer that certain browsers or devices are associated with one another or with your account. To learn more about the browsers or devices we use to measure and improve your experience, check out Your Twitter Data while logged in. To learn more about other browsers or devices we use to measure and improve your experience on the device or browser you are currently using, visit Your Twitter Data while logged out.

What does ‘Personalization across devices’ mean?

By better understanding how different browsers and devices are related, we can use information from one browser or device to help personalize the Twitter experience on another. For example, if you commonly use Twitter for Android around the same time and from the same network where you browse sports websites with embedded Tweets on a computer, we may infer that your Android device and laptop are related and later suggest sports-related Tweets and serve sports-related advertising on your Android device.

What privacy choices do I have?

We are committed to providing you meaningful privacy choices. You can control whether we measure and improve your experience based on browsers or devices other than the ones you use to log in to Twitter (or if you’re logged out, browsers or devices other than the one you’re currently using). You can do this by visiting your Personalization and data settings and adjusting the Personalize across all your devices setting.