After announcing in July that people who use Hangouts in Gmail on the Web will be upgraded to Chat in Gmail, Google today said starting from today, people using Hangouts on mobile will see an in-app screen asking them to move to Chat in Gmail or the Chat app. Similarly, people who use the Hangouts Chrome extension will be asked to move to Chat on the web or install the Chat web app.
Hangouts on the web will continue to be available until later this year. Users will see an in-product notice at least a month before Hangouts on the web starts redirecting to Chat on the web.
Here’s the announcement.