XML Auto Fixer for WordPress Sitemap is a lightweight plugin that automatically removes any unwanted spaces or blank lines that appear before the XML declaration () in your sitemap, RSS feed, or other XML outputs. These invisible characters often cause the common error “XML declaration not at start of document,” which can break your feed or sitemap. This plugin runs silently in the background, detects and cleans the output before it’s sent to the browser—ensuring your sitemap and feeds remain valid and readable by search engines. No settings, no setup — just install and activate. It works with any theme or SEO plugin like Rank Math and Yoast.