Without using any third-party apps, you can hide your photos to notes and as well lock them using a passcode or face id. The process to password protect photos is very simple and the video clearly explains how you can do it without any issues.

There are a couple of apps that can hide photos on an iPhone but if you can do it simply using your Phone then there’s no need to purchase other apps. You can first hide the photos on notes and then password protects the notes. And later if you want to see/use the photo you can simply unlock it, hold and then save it to the gallery.

Thank you.