If someone asked you at what grade level your site’s content was written, could you tell them? What about whether it was fully compatible with every major browser? How many seconds it took to load? Can you confidently state that there are no broken links on your site right now?

Although it may seem unimportant to replace an Rich Text apostrophe with the HTML equivalent or to make sure your WHOIS record is perfect, the reality is that the more accessible and polished your website is, the greater chance you have to secure more readership, and, most importantly, more revenue.

If you’re serious about maintaining a well-rounded, efficient website, the cheapest (and perhaps best) way to make sure you’re on the right track is self-evaluation. To get you started, we’ve put together a list containing 31 of our favorite tools for “grading” your website.

Code Validation

The foundation for every website is fundamentally sound source code. Unfortunately programmers aren’t always the most meticulous type of people. They’d rather hash out the difficult stuff and leave the details to someone else, and that’s where code validation comes in. To make sure your website’s source code and features are fully functional you should run it through the following validation tests.

1. WDG HTML Validator - EDITOR’S CHOICE - Excellent tool for identifying syntax errors on pages driven by markup languages. Also has an option to recursively check for errors on every page in the website directory.

2. W3C Markup Validation Service - Traverses HTML and XHTML markup for syntax errors. Boasts the title of first (and most used) HTML validator on the internet.

3. W3C CSS Validation Service - Checks CSS documents for errors in source code. Also gives warnings for code that doesn’t exhibit the best design practices; e.g. “Same colors for color and background-color in two contexts.”

4. RUWF? XML Syntax Checker - Checks for malformed data in XML documents.

5. W3C Feed Validation Service - Checks the syntax of Atom and RSS feeds for errors.

6. W3C Link Checker - EDITOR’S CHOICE - Searches for and identifies broken links. Specifically checks that all the links are dereferenceable, no links and anchors are defined twice and warns about invalid http and directory redirects.

7. Juicy Studio Link Analyser - Tests the links on a page for Urls that resolve successfully. Works similar to W3C Link Checker.

Accessibility

All too often we see webmasters designing websites that focus on looking attractive while completely failing to consider the impact of visitor accessibility. Unfortunately, an ineffective or difficult to navigate website is certain to fail, no matter how attractive it is. To make sure your visitors are getting the information they need (and thus becoming repeat visitors), your website should follow various WCAG and section 508 accessibility guidelines.

8. Watchfire WebXACT - EDITOR’S CHOICE - A must use tool for all serious designers and developers. Generates a very detailed report on the quality, accessibility and privacy of a website.

9. ATRC Web Accessibility Checker - Tests webpages for WCAG 2.0 Level2 compatibility. Generates a report with a series of recommendations for bringing headers, links, metadata, tables and text up to speed.

10. WAVE 3.0 Web Accessibility Tool - EDITOR’S CHOICE - Highly customizable tool that uses a graphical model to display website compatibility issues with WCAG 1.0 and section 508.

11. TAW Web Accessibility Test - Tests webpages for conflicts with WCAG 1.0 compatibility and reports issues via a graphical model. Generates recommendations based upon WCAG priority model.

12. HiSoftware CynthiaSays portal - Uses a very strict policy to test webpages for section 508 and WCAG 1.0 compliance. Reports results in an extremely detailed (yet difficult to read) table.

13. HERA Accessibility testing with Style - Uses a very sophisticated and easy to read approach to point out WCAG 1.0 compatibility issues with a particular webpage.

14. Juicy Studio CSS Analyser - Performs a color contrast test to make sure your sites CSS color scheme meets WCAG 1.0 requirements.

15. Juiciy Studio Readability Test - Analyzes the language on your website based upon the Flesch Reading Ease and Flesch-Kincaid grade level algorithms. Useful for determining if you’re speaking over the head of your readers.

Speed

How fast your website loads is often a key factor in getting visitors to return. In many cases if a visitor has a slow internet connection, they won’t even bother to visit websites dominated by large images, flash files and multimedia documents. To maximize your website’s reach, you’ll need to maintain webpages that can get the job done fast.

16. Web Page Analyzer from Website Optimization - EDITOR’S CHOICE - An excellent tool that analyzes a webpage and gives recommendations for decreasing loading time. Focuses on optimizing the number of objects, images and overall size of the webpage.

17. WebSitePulse Test Tools - A series of tools for identifying website load times and hostname information.

18. Internet Supervision Url Check - Generates load times of your webpage from various servers around the world. Useful for determining if your extended audience is actually receiving your message.

Browser Simulators

Perhaps the most common problem in web development is failing to make sure that a website renders properly for every operating system and browser. Attempting to address the problem manually, however, is never an easy task because developers typically have access to two operating systems (at best) and usually no more than a few browsers. To combat this we recommend you check out the following resources that allow you to see what your website looks like on various platforms.

19. Browsershots - Takes screenshots of your website in various browsers and platforms including Firefox and Internet Explorer on Windows, Firefox and Safari on Mac OS X and Iceweasal and Konqueror on Linux. Unfortunately the tool requires you to wait up to three hours in a processing queue before retrieving your screenshots.

20. IE NetRenderer - Generates real time screenshots of your website on Internet Explorer versions 5.5, 6.0 and 7.0.

21. MobiReady Report – Analyzes your webpage for compatibility issues on a mobile phone. Generates a detailed report on potential viewing problems and offers a glimpse as to what the website would look like on two different types of mobile phone browsers.

Search Engine Optimization (SEO)

Developing a website with an “SEO friendly” model is a sure way to gain an edge on the competition. By making the most out of the following tools, you’ll develop a better understanding of who your audience is and will likely help you come up with more effective ways of appealing to them.

22. UrlTrends - EDITOR’S CHOICE - Graphically displays a website’s visitor traffic information by search engine prevalence. Extracts information from Google, Yahoo, MSN, Alexa, AlltheWeb, AltaVista and more.

23. iWEBTOOL Backlink Checker - Excellent tool for figuring out which sites are linking to yours, and what part of the site they’re linking to.

24. iWEBTOOL Multi-Rank Checker - Neatly displays your pages’ Alexa and Google PageRank stats.

25. Microsoft adCenter Labs: Advertising and Keyword Research Tools - EDITOR’S CHOICE - A fantastic set of tools for analyzing and predicting the audience and market of your website.

26. Domain Tools Whois lookup - Comprehensive Whois tool that displays all of the standard domain information and calculates the efficiency of a websites markup when seen through the eyes of a search engine spider.

27. SEO-Browser - Strips your website of all the “pretty” components to show you how it looks to a search engine. Very useful tool to make sure your design is on the right track.

28. SEO Workers SEO Analysis Tool - EDITOR’S CHOICE - Extremely useful tool that analyzes an assortment of page features including meta tags, keyword density and load time.

29. Seekport Seekbot - Analyzes a website’s metadata and textual content to determine how effective a search engine would interpret the website.

30. SEO Chat SEO Tools - A stock pile of SEO tools for measuring Google AdSense earning potential, keyword density, meta tag effectiveness and much more.

31. Marketleap Search Engine Marketing Tools - A group of tools used to analyze the popularity of a particular webpage, how well your site is indexed in search engines and how well you rank for particular keywords.