Takes about 10 seconds. We only look at the site's home page, the same way a visitor's browser would.
WHAT WE CHECK
Security
Does the site have a working padlock (HTTPS), or do visitors get a "Not secure" warning?
Phones
Does the site fit a phone screen, and can customers tap to call?
Speed
How quickly the page loads, and whether the server compresses it.
Google basics
Title, description, headings, image descriptions, and whether anything is hiding the site from search.