# SISTRIX — the record

German SEO toolmaker whose 17-week, 1.5-million-snapshot study is the record's base rate for citation drift.

One item, and the record's base rate for citation drift: SISTRIX re-sampled 82,619 prompts weekly for 17 weeks — 1,548,213 snapshots across six countries and three surfaces — and found Google replacing 56% of its cited sources every week and ChatGPT as much as 74%, with a stable core of a few domains on 86% of prompts and 89% weekly rotation outside it. AI Overviews and AI Mode cited different domains 83% of the time; only 1.4% of cited news articles stayed permanently. Vendor-published and not replicated.

Also known as: https://www.sistrix.com/

- 2026-09-01: SISTRIX: ChatGPT replaces 74% of its cited sources every week (https://anythingengineoptimization.com/item/2026-09-01-sistrix-chatgpt-replaces-74-of-its-cited-sources-every-week/)
  The largest public measurement of citation drift re-sampled 82,619 prompts weekly for 17 weeks, from December 17, 2025 to April 8, 2026, producing…

Canonical: https://anythingengineoptimization.com/entity/sistrix/
From Anything Engine Optimization (AEO Wire) — https://anythingengineoptimization.com/entity/