Passing a link to a third party checker is not at all helpful for security (though you may have uses for it). The link can conditionally redirect somewhere else when you use a real browser, so you can get a false result. And it means you have now fallen for the problem; you believe you know exactly where the link will end up, and you will fail to check it again.

But if you want to do that, that's fine, you can do so. Use a third party QR code scanner app, and do what you like with it. Just bear in mind that you absolutely cannot trust anything based on the URL you initially load. You can only trust the address field that shows a URL where you land.

You also have not checked every other URL that you loaded, whether that was tapping a link, tapping a form submit button, tapping on a random web page element, having the page use window.open, location.href or meta refresh. You seem to think a QR code is something extra special that you need to be especially scared of, when you load untrusted links all the time from websites and search engines. Actually, a QR code is the same as any of those things, and you use them every day without checking the URLs that will load first.

Sync: keeping history and open tabs seperate