Site responds The site has to load. If this fails nothing else can be measured.
Served over HTTPS Browsers mark plain http:// pages as Not Secure. Most hosts turn on a free certificate with one switch.
Title tag, 15–65 characters The blue headline in Google results and the text in the browser tab.
Meta description, 70–165 characters The grey line Google prints under your title. Without one, Google picks a sentence off your page at random.
Mobile viewport declared Without this line phones render your site zoomed out and unreadable. Most of your customers are on a phone.
One clear H1 heading One main heading tells search engines what the page is about. None or several is ambiguous.
Structured data (JSON-LD or microdata) Machine-readable facts - address, phone, hours. This is what puts a business in a map card instead of a plain link.
At least 300 words on the page A page with almost no words gives search engines nothing to match a search against.
llms.txt or AGENTS.md for AI search Plain text files that tell ChatGPT and Perplexity what your business does. Almost nobody in Austin has one yet.