Page experience
Images, loading priority, layout shifts and mobile basics.
SEO CTF rooms (6) Virtual Lab scenarios (5) Free resources (6) Courses
SEO CTF rooms
See all in SEO CTFShort rooms that train one skill at a time: read a quick lesson, then answer questions to earn CTF points. Log in or join free to play.
- Medium Core Web Vitals LCP, INP and CLS: the user-experience metrics Google measures in the field. Members only
- Easy HTTPS and Secure Pages Serve every page over HTTPS and move a site across without losing traffic. Members only
- Easy Mobile Usability: Pop-ups, Viewport and Tap Targets Make pages easy to read and use on a phone, without anything in the way. Members only
- Easy Intrusive Interstitials and Dialogs Promote, ask for consent and gate content without blocking the page. Members only
- Medium Image and Font Optimisation Ship smaller images and faster fonts without hurting LCP or CLS. Members only
- Hard Debugging LCP, INP and CLS Break each Core Web Vital into its parts and fix the part that is slow. Members only
Virtual Lab scenarios
Open Virtual LabFull scenarios: you get a brief and your own practice website, optimise whole pages and watch them rank in a practice search results page. A lab passes only when your fix is really in place. Log in or join free to start one.
- Beginner The homepage photo that loads last A wedding venue's homepage takes ages to show its main photo on phones, and the page jumps while it loads. Fix it in the HTML. Members only
- Beginner Pages that do not fit a phone screen A clothing store's pages were built by different developers, and some of them render like a shrunken desktop page on phones. Find every template that breaks on mobile. Members only
- Intermediate A speed plugin that slowed every recipe A food blog installed a speed plugin that lazy-loads every image and strips image sizes. The recipe pages got slower. Undo the damage without breaking the one page the plugin skipped. Members only
- Intermediate Retiring the old mobile pages A restaurant still runs a cut-down copy of its site for phones under /m/. Move everyone to the main pages without losing anything customers relied on. Members only
- Advanced Capstone: speed up the landing page before the ad campaign Fix the main image, lazy loading, layout shifts, a phone-breaking template and an app-install overlay on a fashion landing page and its collection page. Members only
Free resources
- robots.txt introduction and rules How Google reads robots.txt, including group and rule precedence.Free
- JavaScript SEO basics How Google renders JavaScript and the common traps.Free
- Core Web Vitals (web.dev) What LCP, INP and CLS measure and their thresholds.Free
- PageSpeed Insights Field and lab performance data for any URL.Free
- Screaming Frog SEO Spider Desktop site crawler; the free version crawls up to 500 URLs.Freemium
- TechnicalSEO.com tools Free utilities such as a robots.txt tester, hreflang generator and fetch-and-render.Free