The crucial SEO metrics that should be tracked are as follows:-

Organic Traffic:- This metric measures the total traffic your website should receive from the search engines. It is the best indicator of how good your website is ranking for relevant keywords and gaining organic traffic.
Keyword Rankings:- This metric is used to hold the position of your website on search engine results page(SERPs) for specific keywords. It is used to track the ranking for relevant keywords that help you to understand the visibility, and identify areas for improvement.
Click-Through Rate(CTR):- This metric is used to indicate the percentage of people who click on your website through links in the search engine results pages. A high CTR always shows that your website title and description are compelling and effectively grab user attention.
Bounce Rate:- This metric is used to indicate the percentage of traffic who leave your website after viewing only one page. A high bounce rate shows that your landing pages are not engaging or relevant to the user's search intent.
Conversion Rate:- This metric is used to indicate the percentage of website traffic who has completed the desired action like making a purchase, subscribing to a newsletter, or filling out a form. It's vital to understand the effectiveness of your website in driving the most valuable business outcomes.

Page Speed:- This metric is used to indicate how quickly your website loads. A slow loading speed can negatively impact the user experience and the ranking of your website, that's why you have to optimize your website according to speed.

Define the Crucial Seo Metrics You Should Track.