Website health
How do I know if my website is mobile friendly?
Short answer: Open it on a phone and check text, navigation, forms and tap targets. A viewport tag is helpful, but by itself does not establish mobile usability.
The full answer
The key technical sign is a "viewport" tag in the page, which tells phones to fit the page to the screen.
Most modern website builders and themes include it. If yours doesn't, switching to a responsive theme is usually the simplest fix.
Want step-by-step help? Read Your Website Doesn’t Work Well on Phones: How to Fix It.