SiteKeywordDensity.com - Keyword Density Report
Word Counter - A simple, beautiful word and character counter
WordCounter.net - Count words, sentences, paragraphs etc.
CountOfWords.com - CountOfWords.com is a handy tool that detects the number of words in a given text and tells you the total amount.
KeywordDensityAnalyzer.com - Website Keyword Density Analyzer Tool
Count Wordsworth - Count Wordsworth makes it easy for you to monitor your literature-related metrics online.