How can I improve the SEO performance of a WordPress website?

Yes. For a WordPress website, I would use a combination of performance tools and a basic SEO/UX audit rather than relying only on Firefox. For speed, start with Google PageSpeed Insights to check Core Web Vitals, loading time, and issues affecting mobile and desktop users. For images, EWWW Image Optimizer is useful for compression and converting images to WebP. As a general target, try to keep most images around 100–140 KB or less where practical, without noticeably reducing quality. For JavaScript, check which scripts are actually needed and look for opportunities to minify and reduce unnecessary JavaScript. You can also use Firefox Developer Tools to inspect the page and identify scripts that may be causing delays. For search visibility, I would audit the whole website and check: * Make sure important pages return 200 status codes. * Find 404/broken URLs and use relevant 301 redirects where appropriate. * Check the website's UI/UX and mobile responsiveness. * Avoid keyword stuffing and keep the content natural. * Check whether two pages are targeting the same keyword and potentially competing with each other. * Make sure every important image has relevant alt text. * Keep important pages easy to reach through internal links, ideally within 1–2 clicks from relevant pages. * Implement Schema markup correctly and make sure it matches the actual content on each page. Firefox Developer Tools can then be used alongside these checks to inspect layout, network requests, JavaScript, responsive behavior, and other browser-specific issues. Testing the site on both desktop and mobile screen sizes is especially important because a page can perform well on desktop while still providing a poor mobile experience.