Word Count Tools - The must-have free word counter that provides an extensive report about the word count, character count, keyword density, readability & many other useful stats.
WordCounter.net - Count words, sentences, paragraphs etc.
WebsiteKeywordDensity.com - Website Keyword Density Tool
TextPipe - Search and Replace, Find and Replace, Web Sites, Database Extracts, XML, CSV, Tab, mainframe COBOL data and more
KeywordDensityAnalyzer.com - Website Keyword Density Analyzer Tool
NimbleText - NimbleText is a text manipulation and code generation tool available online or as a free download.