More free checks

These sit one click away from the home page. Each one is still a public page.

• AccessibilityAlt text, contrast, headings and links on one page.
• SpeedCore Web Vitals, on a phone and on a desktop.
• LinksBroken links on the page, and a few more pages on the same site.
• Share previewHow the link looks in a message.
• Structured dataStructured data on the page.