SEO Tools
SEO by the Hour uses a variety of free and paid SEO tools to help analyze and optimize websites. Here is a list of free tools to help you do some very basic SEO yourself.
Keyword Research
Google Keyword Suggestions - Google provides how many searches are performed on their search engine for any list of terms
Keyword Spy - Check the websites bidding for a keyword, or the keywords a partcular site is targeting
SEM Rush - Check the competition for any keyword, or the keywords a web site is targeting (same as above :)
SpyFu - Another competition and keyword analyzer/spy
iSpionage - One more tool to analyze the target keywords of any website, or the websites targeting a particular keyword
Onpage Analysis
Google Webmaster Tools - Make sure everything looks good here before anywhere else
SEO Workers - Great onpage SEO analysis tool (old school but still good)
CopyScape - Make sure your content is unique from all other content on the web
Plag Spotter - Plagiarism tool very similar to CopyScape, but some will argue that it's better :)
Other SEO Tools
Way Back Machine - Check how a website used to look since it was first crawled
Class C Checker - Check to see if 2 different websites are on the same server. Other SEO Chat Tools
SEO Book Firefox Extensions - SEO analysis, search engine research, keyword rank checker and more tools, by SEOBook.com
XML & HTML Sitemap Generator - Bot crawls your website and creates XML sitemap, HTML sitemap, ROR file and more
Quintura - Great visual search engine to see keyword density of top ranking sites for various search queries
Click Here to View Link Building Tools
Click Here to View Bigger Lists of SEO tools (external)
