huh?

This page loads (without any special Expires headers)

img src="https://www.phpied.com/wp-content/uploads/2019/01/prettier.png?get=1"

and

img src="https://www.phpied.com/wp-content/uploads/2019/01/prettier.png#hash=1"

then it tries to find resources with the resource timing API:

      onload = () =>
        [
          'https://www.phpied.com/wp-content/uploads/2019/01/prettier.png?get=1',
          'https://www.phpied.com/wp-content/uploads/2019/01/prettier.png#hash=1',
          'https://www.phpied.com/wp-content/uploads/2019/01/prettier.png'
        ].forEach(u => res.innerHTML += `\n${u}: ` + performance.getEntriesByName(u).length);

Observed behavior

Chrome finds prettier.png?get=1 and prettier.png#hash=1 as expected
FF does too, mostly. Except when things are cached, it finds neither. To demonstrate go back and click hash.html. Also sometimes when you refresh, sometimes it finds prettier.png?get=1, sometimes it finds #hash=1
Safari finds prettier.png?get=1 and prettier.png, so it ignores the hash