As we all know there are thousands of SEO extensions for Google Chrome. Here are the 5 SEO tools I would recommend to understand and improve the site SEO factors.

(1) SEO for Chrome

This tool SEO for Chrome provides SEO Tools like to find Pages indexed, competitive analysis, keyword research, backlink checks, pagerank checks etc.

https://chrome.google.com/webstore/detail/oangcciaeihlfmhppegpdceadpfaoclj

2) SEO SERP

A simple SERPS tool to check the position for a list of websites for a given keyword.

https://chrome.google.com/webstore/detail/ofoaoaloeipdofknnaapbmdddddioklg

(3) SEO Site Tools

This tool provides the Social Media information, external page data, HTML and CSS Validation etc.

https://chrome.google.com/webstore/detail/diahigjngdnkdgajdbpjdeomopbpkjjc/

(4) SEO Professional Toolbar

This tool stores the rank and backlinks history for selected sites.

https://chrome.google.com/webstore/detail/adecfhccdknoobplgempjhbojlbpahhn

(5) Mozbar 

This tool shows the important SEO metrics and also compares link metrics for Google, Bing and Yahoo! with the SERP.

https://chrome.google.com/webstore/detail/eakacpaijcpapndcfffdgphdiccmpknp/

These SEO extensions for chrome can help you get an overall audit of your website popularity and these tools can help to improve the site performance in a better way.