Finally, I have discovered why my landing page has lower conversions on mobile

I redid my landing page three times this year, thinking that the problem was the copy. In reality, it turns out that the problem was even dumber – on the mobile version of my website, my hero CTA button is placed below the fold on any device that's smaller than the iPhone 13. No one scrolls and no one clicks. Luckily, I found out about this because I've seen it happen to a friend on her personal phone, instead of me doing the tests on mine.

It has made me question how many "conversion optimizations" I have actually been doing myself by just testing everything on my device and assuming that everyone else will see the same thing.

Do you test your onboarding process and landing pages on devices that are not yours personally, or do you rely more on analytics services to catch this stuff?