Bookmarklets are intelligent shortcuts on your bookmark toolbar without the need for installing a Browser Plugin that often contains adware. It saves you time because you can get the info you want with just 1-click instead of navigating to the website and then typing in the relevant data.

To activate a bookmarklet you drag the link to your bookmark toolbar in Firefox or Chrome.

SimilarWeb
This bookmarklet allows you to check the traffic stats widget with just 1-click whenever you visit a page. The widget is a mini version of the acutal website statistics so it loads very fast.

Alexa
This bookmarklet allows you to view the Alexa stats with 1-click.

DomainSpy
Whois bookmarklet to get domain whois info and other extensive information about the domain. It also has useful quicklinks to 3rd party domain tools.

– IP to ISP Converter
– Archive WayBack Machine