In iOS, the read receipts option can be toggled on or off in the Settings app, under Messages, or within individual conversations by tapping on the person or group at the top, tapping “Info,” and enabling/disabling “
This will bring up a “context menu” offering a preview of conversation thread; you’ll be able to see the new message’s entire contents and even a few previous messages—everything that fits on the screen at one time.
This preview feature of-sorts only works on iPhone 6S or later, so on the off chance you still use a 6-year-old iPhone, you’re out of luck (also, it’s probably time to get a new phone).
Changes including adding information to cover iPhone’s implementation of haptic touch, expanding upon and clarifying the steps involved and adding a new header image and screenshot.