Having a successful website can be a bit difficult. Even if the content of your website is awesome, making it relevant for Web searches (thus, easy to reach for worldwide Internet users) requires a lot of effort. SEO (Search Engine Optimization) tools are designed to help you increase the visibility of your website. Here are some of the most useful SEO analysis services that work online, so they won't require you to install anything on your computer.
GMetrix is a handy tool that will analyze your webpage loading speed and will tell you exactly what you need to do to make things better. The tool uses two other services (PageSpeed and YSlow) to determine how fast your webpages load, then calculates a grade so you can instantly realize how good (or bad) you are doing. Below the grades, Gmetrix gives you detailed information about every single thing that wasn't as good as it could have been, and tells you how to deal with the situation (optimize images, leverage browser caching, minimize CSS and HTML, etc.)
Google Analytics is my favorite tool out of this entire list. This service can give you detailed information about the traffic on your website (number of visitors, where they come from, etc.), and it can also serve in helping you understand why the visitors interact in a certain way with your site. Furthermore, the tool also gives you relevant data about conversions and revenue, so you can form an accurate opinion about the worth of your domain. Google Analytics has a free version, but if you're a professional in the field, you should probably opt for the premium subscription which costs $150 per year.
Google Webmaster Tools
Google Webmaster Tools is one of the best SEO analysis services that you can come across. Why? Because this tool will tell you exactly how Google looks at your website and can even help you do something about it. Even though Google Webmaster Tools can be used free of charge, first you will need to sign up and use one of the available methods to verify that the website you are interested in actually belongs to you.
Bing Webmaster Tools
Even though it is underrated and most of the times overlooked, Bing Webmaster Tools remains a great SEO Analysis tool. This service offers you details about your website's indexation, keyword optimization, crawling, etc. Furthermore, the tool can give you an insight into the way Microsoft's search engine (which powers Yahoo as well) treats your website. Lastly, the Help section provided by Bing Webmaster Tools is also a big plus for the service.
SEO Book SEO Toolbar
This service has to be downloaded, so it kind of breaks the rules we established in the beginning of the article, but since it's a browser tool I thought I should include it anyway. Developed by SEOBook, Seo Toolbar will display some interesting details about the webpages that you visit, so you can quickly get information about your site as well as others that you want to compare it to. This toolbar will show you the website's Google PageRank, the number of links leading back to your site, the number of unique visitors per month, an estimation of the revenue generated by the traffic, etc.
URL is another reliable website analysis tool. This service will give you details about server headers, the number of HTTP requests that your website receives, its loading speed, information about the objects that were loaded, and comprehensive data regarding the internal and external links found. What's really cool about URL Valet is that it allows you to customize the analysis by letting you select the HTTP protocol and the specific browser that you want to check for.
WooRank is an interesting tool that can perform an in-depth analysis of your website. This service can be used without paying a dime, but you will only be allowed to generate one report per week, so if you need more - you will have to pay for it. The good news is that even in the free version you can see your previous reports, so you will be able to see whether your website is making progress or not. This tool will provide you with data about your visitors, the social buzz that your site has generated (Facebook, Twitter, etc..), the website's usability, advice on what you need to improve (for the desktop version as well as for the mobile version of your site), etc. The lowest price that you can pay for this service is $49 per month, but you can try out the complete premium functionality free of any charge for seven days to decide if it's worth it.
Another website analysis tool, SiteTrail is a great solution for webmasters. This service gets its data from multiple sources and puts them together to give a complete and accurate report. The tool offers information about your visitors, social media reaction, revenue, links, content, etc. SiteTrail has a few small issues with the reports that it generates, but the service can be used free of any charge so it's definitely worth a shot.
Making sure that your content is unique is very important if you want your pages to be among the first ones that the search engines display. Furthermore, figuring out who is "borrowing" your content for their own benefit should be one of your top priorities. CopyScape is an online plagiarism checker that can tell you which sites offer content that is similar to yours. This service is free, but it can't analyze your entire site, so you will have to input the exact URL for every page you want checked.
SEO-Browser is a very simple tool that is capable of displaying your website exactly the way it is seen by search engines. This stripped-down version of your website is very helpful as it can give you a whole new perspective about the things that you need to improve. Furthermore it helps you bypass a lot of technical stuff that you would otherwise need to use in order to get to this result. The service's most basic functionality can be used for free, but if you need a bit more you will have to pay a fee of $9.99 for one year's worth of access.