Below are some tools and services which help you in knowing the ranking of your web site or the amount of traffic it gets. With these services you can come to know the importance of each keyword that you have used on your web site and how your site ranks on search engines for those keywords. You would then be able to analyse and quantify your search engine optimization efforts. Note: The web site or web page ranking tools and services simply provide an idea how a site/page ranks or how much traffic it generates. The services do not help in increasing your web site rank.
Google PageRank
Google PageRank is a measure of the importance of a web page in the eyes of Google. Page Rank, also commonly called PR, is calculated using a complex formula and mainly depends on the number and the quality of in-bound links to a web page. (FYI, in-bound links are links from other pages to a web page). PR, thus, depends not only on the number of in-bound links from other web pages but also the quality of those other web pages. For example, 10 in-bound links from web pages with PR 8 might result in a higher PR than 100 links from web pages with PR 2. Finally, PR also depends on how many links are there on the external web page.
The idea behind Google's Page Rank is quite logical. The number of in-bound links is sort of basic indicator of how good a web page is. By good, I mean, pages with original content that adds value to the web. Good web pages would therefore have a higher chance of getting in-bound links because other web pages also add value to themselves by linking to such pages.
Additionally, an in-bound link from an important web page (for example, one with PR of 7 or more) would yield a higher PR value. This means that PR also depends on the quality of the web page that link to yours. A handful of links from high quality web pages (those that have high PR values) might yield a higher PR value for your page that a hundred inbound links from shoddy pages.
Finally, the PR value is distributed across the number of links from the external page. For example, to simplify things, consider a web page that links to your page. This page has a PR of 6 and has 20 out-bound links. The PR value of 6 would be distributed across these 20 links. Thus, if you want to increase the PR of your site, you should strive to get in-bound links from pages that have a high PR values themselves and have few out-bound links.
By the way, Page Rank is not a direct measurement of the traffic a web site gets. For that, I advise you to check traffic rankings of your site at Alexa.com. And you should also check the link popularity of your site.
Google.com carries a PageRank of 10 and so do Yahoo.com and MSN.com, though the PR of the latter two keeps shifting to 9 at times. Google PageRank is available on the Google Toolbar
Google Tool Bar.
GoogleRankings.com
Though, "Googlerankings.com is in no way affiliated, sponsored or in any way the property of or responsibility of Google.com.", it's still a great service. What I like about this site is that one can enter a set keywords and find out how a web site ranks in Google. However, I find that the actual rankings (from Google.com) are slighly higher than those reported by Googlerankings.com. For example, my site www.biotechdesk.com ranks third on Google.com for the keyword "biotechnology india", however, GoogleRankings.com reports its rank as 7th. Similarly, for the keyword "biotechnology consultancy" my site gets 6th rank on googlerankings.com while its actual rank when searched for on google.com is 4th.
Note: Google.com ranks keep changing. The above info was obtained on 6th July 2004.
The Googlerankings web site provides several other services - Determining the best keywords of your site and Keyword Density.
GoogleRankings.com
Alexa
Alexa provides several services for web masters including traffic rankings for web sites, number of in-bound links etc. The web site traffic is an indicator of the number of people who came to your site, thus the popularity of your site. The Alexa web site also carries a list of the highest traffic web sites and they provide the list of the most popular web site for a price.
Alexa.com
FreeWebSubmission
This service lists the rank of your web site in 12 major search engines of the web. It checks if the site is listed in the first 100.
www.freewebsubmission.com/site-ranking.html.
