FireFox扩展：
43. W3C Validator(http://validator.w3.org/)
44.WDG HTML Validator – Web Design Group (http://www.htmlhelp.com/tools/validator/)
45.CSE HTML Validator Lite(http://onlinewebcheck.com/)

页面速度测试：页面小、 下载速度快的网页谁深受用户喜欢。
46.Speed Tester – LinkVendor(http://www.linkvendor.com/seo-tools/speedtester.html)
47. Website Speed Test – Web Hosting Top(http://www.web-hosting-top.com/w … .website-speed-test)
48.Website Speed Test – Iwebtool(http://www.iwebtool.com/speed_test)
49.Speed test – WebSite Goodies (http://www.websitegoodies.com/tools/speed-test.php)
50.Web Page Speed Report (http://www.websiteoptimization.com/services/analyze/wso.php)

第四部分：其他SEO工具

PageRank 预测：包括未来预测及当前PR值。
51.Future PageRank – SEO Chat(http://www.seochat.com/seo-tools/future-pagerank/)
52. Predict PageRank – Page Rank Prediction(http://www.pagerankprediction.com/)
53. Future PageRank (http://futurerank.com/rank/)
54.Page Rank Prediction – DNLodge (http://www.dnlodge.com/seo/pagerank_prediction.php)
55. Visual PageRank – Iwebtool (http://www.iwebtool.com/visual_pagerank)
56. Search PageRank – SEO Chat (http://www.pageranktool.net/)
57. Page Rank Tool (http://www.pageranktool.net/)

流量排名：网站的流 量走势及搜索引擎分析。
58.Alexa Traffic (http://alexa.com/site/ds/top_500?qterm)
59. Awstats (http://awstats.sourceforge.net/)
60.Sitetracker (http://www.sitetracker.com/)
61. Histats (http://www.histats.com/)
62.Google Analytics (http://www.google.com/analytics/)
63. Compete (http://compete.com/)

搜索引擎饱和度：搜索引擎索引网站网页的数量。
64.Search Engine Saturation – Market Leap (http://www.marketleap.com/siteindex/)
65.Search Engine Saturation Tool – Build Reciprocal Links (http://www.build-reciprocal-links.com/searchengine-saturation/)
66. Search Engine Saturation – SearchBliss (http://www.searchbliss.com/seo-tools/saturation.asp)
67. Search Engine Saturation Tool – To the Web (http://totheweb.com/tools/sesat/index.php)
68.Search Engine Saturation Tool – SEO Book (http://tools.seobook.com/general/sesat/)