[SEO Test] Tabs and Accordions not OK in Mobile-First

An SEO test was conducted on three sets of mobile-first websites with similar authority. Our results show that content hidden behind tabs and accordions remains devalued. The page ranks, just not enough to compete with a site that doesn't hide the same content. Test Steps:

• Publish content on site A (hidden)
• Fetch and render, submit to index
• Verify index manually in SERPs
• Publish same content on site B (revealed)
• Fetch and render, submit to index
• Verify index manually in SERPs
• Run various queries matching content

In all test queries site B (revealed content) outranked site A (tab/accordion). In addition to that, no query bolding was evident in any desktop snippets for site A. All websites were based on WordPress using the same plugin which renders tabs on desktop and accordions on mobile. Despite other claims and obvious usability advantages, hidden content appears to be devalued in mobile-first index.

no, in the mobile-first world content hidden for ux should have full weight

— Gary "鯨理" Illyes (@methode) November 5, 2016

I want to believe that the above statement is true, and I am wrong. Hopefully the SEO community will run follow-up tests and share their results with us as we've run out of suitable test domains. In the meantime, our advice to clients remains as follows: "If it's important don't hide it."