*From Stanford History Education Group's Civic Online Reasoning
Professional fact checkers do something called lateral reading.
Lateral reading requires opening up another tab to seek information about the webpage you are evaluating. Lateral reading is essential to determining who is behind the information.
Vertical reading is exploring a webpage vertically (up and down) to check things like the date, about section, etc. This will not provide all the information you need to determine if something is trustworthy.