Yoast SEO is a search engine optimization (SEO) plugin for WordPress, made by Yoast BV. SEO is the work of making pages easy for search engines to find, understand and rank. The plugin is installed from the plugin list inside WordPress, and Yoast says it runs on more than 13 million sites.
While an author writes a post, Yoast SEO analyzes the text, shows whether the keyphrase appears in the title, headings and introduction, and gives a readability score from 0 to 100 in more than 25 languages. In the background it creates XML sitemaps (lists of all pages for search engines), adds JSON-LD structured data (schema markup that describes each page to search engines), sets canonical URLs to avoid duplicate content, and adds breadcrumb trails.
The core plugin is free. Yoast SEO Premium, a yearly subscription, adds redirect management, analysis of up to five keyphrases per post and AI help for writing missing metadata.