Hangouts—which Google has recently retconned to "Hangouts Classic"—is Google's most-popular messaging app of all time. The full-featured, consumer-grade, instant-messaging app has over a billion installs on Android, and it has enjoyed prominent placement in the desktop version of Gmail. Since it was an in-place upgrade of Google Talk, it has a user base dating back 13 years.“Hangouts Chat” is the complete opposite. It launched 10 months ago and is a basic (some would say “beta”) enterprise Slack clone. Right now, it’s only available to paying GSuite users, and it has a scant 500,000 installs on Android. Today, the two apps don’t share users, messages, or have any kind of interoperability.
Hangouts Classic (the popular one) is shutting down. Today, Google announced the shutdown begins October 2019, when the company says it will “start retiring” Hangouts Classic for GSuite customers. When, precisely, the shutdown happens for consumers is still up in the air. Google says “We will continue to support consumer use of classic Hangouts and expect to transition consumers to free Chat and Meet following the transition of GSuite customers. A more specific timeline will be communicated at a later date.”