Learn how rel=canonical tells search engines which address is the main version of a page. Understand duplicate URLs, self-referencing canonicals, cross-domain canonicals, redirects versus canonicals versus noindex, pagination, parameters, and common mistakes. Includes a URL normaliser, a canonical decision quiz, and a live canonical checker.
Learn what absolute URLs are in HTML and when to use them. Understand the parts of a full web address, schemes like https, mailto and tel, URL encoding, international domain names, query strings, common mistakes, and best practices on CodeHarborHub.
Learn how relative URLs work in HTML. Understand file paths, same-folder links, subfolders, the parent folder with ../, root-relative paths, the base element, case sensitivity, and common mistakes, explained step by step on CodeHarborHub.
Learn the HTML basics that help search engines find and understand a page: the head essentials, real headings and text, crawlable links, images, clean URLs, mobile and speed basics, and how JavaScript can hide content. Includes a crawler's-view lab, a URL checker, and a live HTML SEO basics checker with a messy and a fixed page.
Learn the HTML base element: how it changes the starting address of every relative link, image and form, how it affects fragment links like #top, how base target works, why it is risky, and what to use instead. Includes a live URL resolver and a base tag checker.