Heytools - JavaScript tools, AJAX tools and some fully server side tools.
Word Counter - A simple, beautiful word and character counter
WordCounter.net - Count words, sentences, paragraphs etc.
Count Wordsworth - Count Wordsworth makes it easy for you to monitor your literature-related metrics online.
TextBuddy for macOS - A Swiss Army knife for plain text.
CharacterCounter.com - CharacterCounter.com is a free-to-use Online Character counter that displays the total number of characters in a text.