SEO is critical to achieving a proper position of your site in Google, this is why I have compiled the top list of Search Engine Optimization tools to help you out.

Google tools

Google Rankings- Check the ranking of a web page in Google™ A free search engine optimization tool.

Prsearch- Shows you Google ranked position, number of pages indexed and Google Dir status.

Adsense Calculator- The AdSense Calculator helps Google AdSense affiliates understand what affects their earnings by letting them experiment with values.

Multi Page Rank Checker- With the Multi PageRank Check you can check the PageRank from different google data centers.

Check Google Pagerank- Now you can check the Google PageRank of any web page without installing the Google toolbar ! Its free and easy – just enter your URL below and press the button.

Search Engine Position- Check your search engine positions on Google Search Engine.

Google Position Tool- Check your position in the google searchresults with this simple tool.

Visual PageRank Overlay- The visual PageRank overlay shows all links of a website and the corresponding PageRanks of the linked pages.

Page Rank Tool- The heart of Google search algorithm is PageRank, a system for ranking web pages. Though engineers at Googleplex are working hard to improve every aspect of Google on a daily basis, PageRank continues to provide the basis for all of their web search tools.

Page Rank Check- With the PageRank check you can verify the PageRank for up to 5 different URLs simultaneously.

Google PageRank Prediction- This predictor tool does what it says, it predicts your future Google PageRank.

SEO Meter- How often search engine visits and crawls website content is an often neglected, but important metric for search engine optimization.

Sitemap Generators

Official Google Sitemap Generator- The Google Sitemap Generator is a Python script that creates a Sitemap for your site using the Sitemap Protocol. This script can create Sitemaps from URL lists, web server directories, or from access logs.

XML-Sitemaps- Create your sitemap with no work at all.

Google Sitemap Generator and Editor- Generates sitemaps with just one URL.

Sitemap Generator Plugin for Wordpress- This plugin creates a sitemap for your WordPress powered site. This is not just another XML sitemap plugin, but rather a true sitemap generator which is highly customizable from its own options page in the WordPress admin panel.

Alexa Tools

Alexa Ranking Tool- Alexa is a very powerful tool used to rank web site traffic. Find out how your web site traffic stacks up against all your competitors! This is one of the most accurate freely available tools to find out how well your site ranks up against millions of other sites on the Web.

Alexa Sparky- Get Alexa data in your statusbar!

Alexa web rank checker- Check your website’s Alexa Web Rank without the toolbar. Alexa Rank Checker also displays your Incoming Links and Reach Rank.

Alexa rank comparison tool- This tool displays a graph from Alexa comparing up to 10 sites.

Backlinks

Backlink Anchor Text Analyzer- This tools help you determine the backlinks of your website and link text used by your backlinks to Link to your wesbite.

Backlink Watch- Type URL of your website to get complete detailed information about quality and quantity of backlinks pointing to your website.

Backlink Checker- Find backlinks linking to a website and their URL information

Backlinks Analyzer tool- Using a regular backlink check (link:domain.com) is a useful tool to find what sites are linking to you, but there are many other Important factors that go into the pagerank formula.

Keyword Analysis & Keyword Suggestions

Keyword Density Checker- Visual depiction of keywords used on a website, keywords having higer density are depicted in a larger fonts.
Ideally your main keywords should appear in larger fonts at the start of the cloud.

Keyword tool- Use the Keyword Tool to get new keyword ideas.

Free keyword suggestion tool- Enter a starting keyword to generate up to 100 related keywords and an estimate of their daily search volume.

Keyword popularity tool- This keyword suggestion tool will help you with the choosing of the right keywords for your website.

Keyword Density- The keyword density tool is useful for helping webmasters and SEOs achieve their optimum keyword density for a set of key terms.

Keyword Difficulty- The keyword difficulty tool is used to analyze the competitive landscape of a particular search term or phrase, this tool issues a percentage score and provides a detailed analysis of the top ranking sites at Google and Yahoo. In other words, this tool will help you determine how difficult it will be to rank for a particular term.

Related Keywords lookup tool- The goRank ontology lookup tool checks the top 1000 Google results for your keywords by running a related word query.

Website Keywords Suggestion- This tools tries to determine the theme of your website and provides keyword suggestions along with keyword traffic estimates.

Nichebot- Finding long tail keywords that are less competitive has never been easier. You’ll even locate hidden keywords most people never find by gaining access to multiple databases (keyword sources).

Keyword Suggestions for Google- The Keyword Suggestion tool for Google will help you choose relevant and popular terms related to your selected key term. Simply enter a key term and this tool will query information from several Google searches, which it will use to determine popular and re-occurring terms used by websites in the same industry.

Search Engine Keyword Tracker & Keyword Ranking ToolThis utility can be used to check search engines (currently supporting Google, Yahoo and MSN) for search engine ranking and track those ranking historically.

Position Checker for Search Engines and rankings

Search Results Analysis- With the keyword position analysis you can check on which position your domain is ranked for a given keyword and compare the first 100 results by Google, MSN and Yahoo.

Rankpulse- The RankPulse Index (RPI) provides an overall glimpse into the daily fluctuations of Google results.

Number of pages indexed- This tool will generate a report showing how many pages of your website has been indexed by the search engines so far. It supports all major search engines: Google, Yahoo, MSN, Alltheweb, Hotbot and AltaVista.

Google Vs Yahoo graph- This tool looks at the results from Yahoo and Google, finds the similarities and then gives you a graphical display of what results are in both search engines.

Spiderview- With the spiderview simulator you see all informations a search engine spider receive from a website.

Marketleap- Their verification tool checks to see if your site is in the top three pages of a search engine result for a specific keyword. It’s important to be in the top 3 pages of a search result because most people using search engines don’t go past the 3rd page.

Search Engine rankings- Search Engine Rankings offers instant, online reports of web site rankings in 8 top search engines and web directories, including Google, Yahoo! Search, MSN, AOL, AltaVista, AllTheWeb, Yahoo! Directory, and Open Directory (Dmoz)

Search Engine Analyzer- This service will search 10 search engines for specified keyword terms.

Meta tag generators & Robots.txt generators

Meta tags generator- Create your sites meta tags instantly to help achieve higher search engine ranking. Includes title tag, description, abstract, keyword, and robot meta tags.

Wired2000- Fast track creating your META tags with their advanced META tag generator.

Webmaster toolkit- Meta Tag Generator will read the page you specify, remove common words from it, and pick the most used words on the page. It will then generate a Meta Keywords tag using the words it has found. Extra weight will be given to words in a heading tag.

Addme- Meta Tags are not always required, but as a rule of thumb, it makes more sense to take advantage of them than to leave them out.

Robots.txt syntax checker- This robots.txt syntax checker checks the contents of a site’s robots.txt against that contained in the latest specification, along with providing warnings on the use of new features that are not yet widely deployed.

Mcanerin international- The robots.txt is a very simple text file that is placed on your root directory. An example would be www.yourdomain.com/robots.txt. This file tells search engine and other robots which areas of your site they are allowed to visit and index.

Yellow Pipe- This freeware utility will assist you in the creation of robots.txt files.

Link Popularity

Market leap- Link popularity check is one of the best ways to quantifiably and independently measure your website’s online awareness and overall visibility. Simply put, link popularity refers to the total number of links or “votes” that a search engine has found for your website.

Site link analyzer- This tool will analyze a given web page and return a table of data containing columns of outbound links and their associated anchor text. If a hyperlink is represented by an image, the image’s alt attribute will be included as the anchor text.

Webmaster toolkit- The Link Popularity Checker tells you how many websites are linking to yours.

Link analysis- The link analysis display all internal and external links of a website with the corresponding anchor texts in a summary table.

Link validation spider- Put your website or weblog home page URL in the input box and a little spider will read the html code and check for the broken links.

Link value calculator- The linkprice calculator reckon the link value per month of a entered website. This link value is calculated from many search engines important factors.

Reciprocal link checker- Reciprocal links have become one of the MOST popular methods of getting backlinks for your website.

Theme link reputation tool- Great tool for analyzing outbound links.

My favorites

SEOQuake- Seoquake is a powerful tool for Mozilla Firefox and for Internet Explorer, aimed at helping web masters who deal with search engine optimization and internet promotion of web sites. Seoquake allows user to obtain and investigate many important SEO parameters of the internet project under study on the fly.

All in One SEO Pack- Optimizes your Wordpress blog for Search Engines (Search Engine Optimization).

Google XML Sitemaps- This plugin will create a Google sitemaps compliant XML-Sitemap of your WordPress blog. It supports all of the WordPress generated pages as well as custom ones. Everytime you edit or create a post, your sitemap is updated and all major search engines that support the sitemap protocol, like ASK.com, Google, MSN Search and YAHOO, are notified about the update.