Download Exiftool from their website
OR
If you have Homebrew installed you can install Exiftool by opening the Terminal app and typing the following and hit ENTER:
brew install exiftool
Open Finder and locate the image or video file. In the Terminal app, run:
exiftool /path/to/file
Replace "/path/to/file" with the location of the file by dragging and dropping the file from Finder onto the Terminal window to autopopulate the file's path.
When you press Enter you should see the file's metadata. For example you may see things like:
Make : Apple
Model : iPhone
Software : 11.4
Megapixels : 0.922
GPS Altitude : 899.28 m
GPS Altitude Ref : Above Sea Level
GPS Latitude : [redacted]
GPS Longitude : [redacted]
Rotation : 90
GPS Position : [redacted]
If you're curious as to how accurate the GPS data is, pop it into Google Maps.
Exiftool preserves the original image and metadata and adds "_original" to to the file name to denote this. A new file is created with the original filename, however this file will not have any metadata.
Using the same file, remove the metadata by running:
exiftool -all= /path/to/file
Note: there is a space between the = and /path/to/file.
To verify the metadata is really removed, view it by running
exiftool /path/to/file
There will still be some data but items like GPS Latitude should no longer be there.
To remove the metadata from all image/video files in a specific folder, you can run:
exiftool -r -all= /path/to/folder
Replace "/path/to/FOLDER" with the location of the folder in the same way as explained in step 2.
Note: there is a space between the = and /path/to/folder.