Word Counter от Mark Lumnert

Word Counter is a simple addon that helps you count words and characters in a selected text.

Simply select text with the mouse, then right-click and choose Word Counter from the context menu. A popup will show the number of total words, total characters, special characters and spaces, average word length, and the longest word. It also shows the number of sentences, unique words, reading time, and average sentence length.

There are three ways to see the results: an alert message, an in-page popup, and a toolbar popup. By default, the result shows in an alert. To change the display style, simply right-click on the toolbar icon and choose one of the options from the context menu. This addon has no options page. Simply add it to your browser and start using it. It works on any web page as long as you can select a word or sentence. With no text selected, it counts the text of the whole page.

In you want to report bugs, or have a feature request, please fill out the bug report form on the addon's homepage (https://mybrowseraddon.com/word-counter.html).