Remove picture metadata on iPhone without downlading and app or the need of internet.

Delete all picture metadata on your iPhone without the need of an app or internet.

All you need to is,

Step 1: Open the Shortcuts app on your iPhone.

Step 2: Open the app, and in the My Shortcuts (Library in iOS 12) tab, hit “+” on top to create a new shortcut.

Step 3: Tap the “Settings” icon, and give the shortcut a name, for example, “Remove EXIF data.” You can also tap the “Icon” to change it to something that matches your shortcut’s function better.

Step 4: The first step is to select the desired photo. You can do this by adding the “Select Photos” action. (Note: When you run the shortcut, you will be prompted to request access to Photos app. Ensure you allow access.)

Step 5: As a next step, add “Convert Image” action. This will allow you to convert the image to any desired format with an additional option to remove EXIF data.

Step 6: By default the “Convert Image” action will convert the image’s format from .PNG to .JPEG. But since our intention is to just remove EXIF data, select the target format as “Match Input.” This will retain the output image format to match the input.

Step 7: Remove the EXIF data associated with the photo by turning off the option “Preserve Metadata.”

Step 8: The next step is to share the photo without the EXIF data. This can be done by adding a “Share” action. This will open up the Share Sheet when you run the shortcut.

Step 9: The shortcut is complete. You can now run it by hitting the “Play” button. In iOS 12, it’s located on top. Upon running the shortcut, you’ll see an album view of the Photos, from which you need to select a photo. Once done, it will prompt you to share the converted photo without EXIF data.

This will remove any metadata from your pictures and you will also know that there isn't a third party involved collecting any data from you.

TLDR: Don't use an iPhone

Most definitely don't use an iPhone.

From the ReviewsOz Guide

Linux

sudo apt install imagemagick -y

Open a shell in the pic directory

Type mogrify -strip *.*

I don't know of a Linux Distro that needs step 1. They have to exist.

True but still useful for some