What do you check first when judging page readability?

I’m building ReadScore, a Chrome extension that analyzes web page readability and shows:

• Readability score

• Reading time

• Words per sentence

• Highlights for complex sentences and dense paragraphs

I’m curious how you judge if a page is easy or hard to read.

Do you look at sentence length, text blocks, reading time, or something else?

Your answers help me decide which signals and highlights should matter most.