Here are some of my favorites tools that helps me to QA web sites directly from the browser
Check My Links: this is a tool that crawls through your webpage and looks for broken links (404), redirect links, and highlight the good links, really simple to use (https://chrome.google.com/webstore/detail/check-my-links/ojkcdipcgfaekbeaelaapakgnjflfglf)
GoFullPage: Tool used for screenshots and PDF exports, it has the feature that you can take a screenshot of the page total height, creating it in a new tab (https://chrome.google.com/webstore/detail/gofullpage-full-page-scre/fdpohaocaechififmbbbbbknoalclacl)
BugMagnet: Tool that automates Forms completion, a really great tool for exploratory testing (some how it will automate the form submission with a couple of clicks) https://chrome.google.com/webstore/detail/bug-magnet/efhedldbjahpgjcneebmbolkalbhckfi
Selenium IDE: browser action recorder, able to repeat actions , and export some of the actions recorder in format of code for your automations https://chrome.google.com/webstore/detail/selenium-ide/mooikfkahbdckldjjndioackbalphokd
Color Picker Tool: Tool that extracts a selected color from a webpage thru a graphic interface, it returns it on the hex code, and it even has a history of colors inspected
SEO Meta in 1 Click: SEO analyzer, a tool that displays all meta tags/data and main seo information clearly. By using this tool, you can better manage and improve your SEO and visibility on Internet, showing a red color on the items that need to be addressed https://chrome.google.com/webstore/detail/seo-meta-in-1-click/bjogjfinolnhfhkbipphpdlldadpnmhc
WCAG color contrast checker: Contrast checker between background and fonts, useful for ADA validation according to the WCAG 2.1. https://chrome.google.com/webstore/detail/wcag-color-contrast-check/plnahcmalebffmaghcpcmpaciebdhgdf
PR Page Reader: Page reader, simulates reader for people with vision disability