Checking the compliance of your site's pages with web standards is important both for the speed of your pages and for minimizing code errors that may be overlooked. We recommend that you visit validator.w3.org on w3c.org to check your page code, and jigsaw.w3.org/css-validator to check the compliance of your CSS style file. With the help of these two references, you can see errors both on the page and in your style files and get information about what you need to do to fix them.
Another issue that should be noted in terms of on-site SEO regarding coding compliance is that you should avoid preparing your page with old-style coding forms such as tables and frames. A page prepared using CSS styles and Divs has been found more acceptable by search engines than a page prepared with tables or frames. Professional web design companies complete this process in a very short time and with quality work by using SEO-compatible WordPress themes.