Web Standards is a broad term describing the use of “best practices” when developing a website. Quality website development includes a wide range of considerations to build sites that are fast, clean, CSS-based, accessible, usable and search engine friendly (in addition to what the owner wants).
Some of the considerations that go into building a quality site:
Quality of code
Does the site use a correct Doctype?
Does the site use a Character set?
Does the site use Valid (X)HTML?
Does the site use Valid CSS?
Does the site use any unnecessary CSS classes or ids?
Is the code well structured?
Does the site have any broken links?
Does it have the best speed/page size?
Separation of content and presentation
Does the site use CSS for all presentation aspects (fonts, color, padding, borders etc)?
Are decorative images in CSS or (X)HTML?
Accessibility for users
Are “alt” attributes used for all descriptive images?
Does the site use relative units rather than absolute units for text size?
Do any aspects of the layout break if font size is increased?
Does the site use visible skip menus?
Does the site use accessible forms?
Does the site use accessible tables?
Is there sufficient colour brightness/contrasts?
Is colour alone used for critical information?
Is there delayed responsiveness for dropdown menus (for users with reduced motor skills)?
Are all links descriptive (for blind users)?
Accessibility for devices
Does the site work acceptably across modern and older browsers?
Is the content accessible with CSS switched off or not supported?
Is the content accessible with images switched off or not supported?
Does the site work in text browsers such as Lynx?
Does the site work well when printed?
Does the site work well in Hand Held devices?
Does the site include detailed metadata?
Does the site work well in a range of browser window sizes?
Is there a clear visual hierarchy?
Are heading levels easy to distinguish?
Is the site’s navigation easy to understand?
Is the site’s navigation consistent?
Does the site use consistent and appropriate language?
Does the site have a sitemap page and contact page? Are they easy to find?
For large sites, is there a search tool?
Is there a link to the home page on every page in the site?
Are links underlined?
Are visited links clearly defined?
Does the site have a helpful 404 error page that works from any depth in the site?