Make sure you save before deleting the conversation.
With more and more people using messages these days to communicate, it’s inevitable that someone will send you a message that contains a photo you want to save.
You can easily save a photo you see in a message conversation so it will be included with all of your other photos. Press and hold the photo. You'll see the option to save the photo.
You can also view all photos you've received in the message conversation. In fact, you’ll want to do this before you delete a message conversation since all of the photos associated with it will be deleted.
Here’s how to view photos sent in Messages:
Go to the message conversation and select the down arrow next to the name. You'll see the ‘i’ in the upper right.
You’ll see a list of photos and videos associated with the conversation. Press and hold the photo you want to save for more options.
You can select multiple photos to save (or delete) by tapping the circle until you see the blue check mark. Then select 'save image' in the bottom left.
Selecting Save Image will save to your photos.
Photos and videos in message conversations can use up a lot of space on your iPhone, so make sure you manage them wisely!