W3 Consortium
The World Wide Web Consortium (W3C) is an international organization that sets standards for the web to ensure that it is accessible, functional, and interoperable for all users and devices. These standards are important for search engine optimization (SEO) because they ensure that web pages are structured in a way that is easy for search engines to understand and index.
The W3C was founded in 1994 by Tim Berners-Lee, the inventor of the World Wide Web, and is now run by the Massachusetts Institute of Technology (MIT) and the European Research Consortium for Informatics and Mathematics (ERCIM).
W3C Validator
It is difficult to estimate the exact number of web developers or search engine optimization specialists who use the W3C online validator, as it is just one tool among many that these professionals may use in their work. However, the W3C online validator is a widely used and respected tool in the web development and SEO communities, and it is likely that many professionals in these fields make use of it as part of their workflow.
The W3C online validator is a tool that allows users to check the syntax and structure of their HTML, CSS, and other web-based code to ensure that it meets the standards set by the W3C. By using this tool, web developers and SEO specialists can ensure that their code is clean, well-formed, and compliant with the standards that are important for SEO and the overall functionality of the web.