Google tests editing for the Google Messages app that will allow a change to a posted message within 30 minutes after it is sent.
If you’re an Android user, the Google Messages app is the one that you should use. It has all of the RCS features that you want including end-to-end encryption, read receipts, typing indicators, high-quality image sharing, and more. Google Messages beta users can now try the message editing feature that gives them 15 minutes to edit a message that has already been sent.
Now here is something important to know. The person to whom you sent the original message must also be using a beta version of Google Messages for this feature to work. That requirement is something that will not be necessary once the feature is out of beta.
To check to see if you are a Google Messages beta member, open Settings > Apps > Messages and scroll to the bottom to see which version of the app you are running.
