There's a simple test for this. You can generate a page with tons of the same letter or number, and a few outliers. A person with synesthesia will be able to in

There's a simple test for this. You can generate a page with tons of the same letter or number, and a few outliers. A person with synesthesia will be able to instantly spot the outliers while a neurotypical person won't. Something like https://www.synesthesiatest.org/blog/synesthesia-test-variations https://www.synesthesiatest.org/blog/synesthesia-test-variat...