Building according to web standards: Why are web standards important?

The use of web standards in the production of websites has a number of benefits in terms of accessibility, stability and sustainability.

Accessibility

Sites that are built in accordance with web standards are easier to use for people with 'non-standard' browsers, such as screen readers, Braille displays, speech synthesisers, text browsers and palmtop browsers with limited screen dimensions.
It is not feasible to build and maintain an alternative website for every conceivable particular user situation.
Web standards offer the technology to take account of most user situations within one version of a website. The application of web standards is the best guarantee that a website is accessible to both new and old web browsers, ‘non-standard’ browsers, search spiders and new media, such as mobile internet.

Visibility of the site in search engines.
A site built according to web standards is easier to understand and can be more accurately indexed for search spiders. This makes it easier to, add your own search engine to the website, while the results from this search engine will be more accurate.
Web standards were developed with backward compatibility in mind.
Older browsers will still understand the basic structure of the site and display the content, even if they do not support the newer technologies (see also Progressive enhancement). The same applies to search spiders.
Building according to web standards offers the web developer an opportunity to validate produced code.
Validation services give a summary of errors in the code, making the web developer’s task easier and thus saving time.
Web pages built according to standards can simply be converted to other formats, such as a database, Word or PDF files.
Variety in the supply of information lies within reach. Furthermore, it makes migration to other applications easier.

Most web standards have been developed with backward compatibility in mind.
This means that sites built with older versions of the standard will work in new browsers and that sites made with newer versions of the standard will still be accessible in older browsers, albeit trimmed down. A principle known as ‘Graceful Degradation’. See also Progressive enhancement.
Throughout its lifecycle, a website will be changed and updated by several web developers and content managers.
Web standards are a collection of rules that every web developer or content manager can learn and follow, which makes modifications to and maintenance of sites easier.