Google's Helios update rolled out in March 2026 and caused the biggest SERP reshuffling since the Medic update in 2018. Health, finance, and B2B SaaS verticals saw the most volatility — with some sites losing 40–60% of organic traffic overnight while competitors doubled their visibility.
What Helios Changed
Helios introduced three major shifts: enhanced E-E-A-T signal weighting (Experience, Expertise, Authoritativeness, Trustworthiness), a new 'content depth score' that penalizes thin content clusters, and upgraded spam detection targeting AI-generated content published without editorial oversight.
- Sites with named, credentialed authors saw average ranking improvements of 12%
- Thin content clusters (under 600 words per page) dropped 2–5 positions
- Pure AI-generated sites lost 70–90% of visibility
- Established brands with strong E-E-A-T saw the biggest gains