On October 27, Semrush published an unusual warning: some Google ranking data it collects may not match what real users actually see. The company calls these poisoned SERPs, and it says the problem is industry-wide, not just a Semrush glitch.
For rank tracking teams, that changes how you should read sudden drops, spikes, and odd keywords. The first move is no longer to rewrite a page: it is to verify whether the ranking was real in the first place.
What poisoned SERPs look like
Semrush describes two patterns. In the first, the entire first page of results is clearly wrong for the query. In the second, the page looks normal at the top, but deeper results only loosely match the search.
The example Semrush gave is a vivid one. A search in Brazil for a specific baby stroller model returned a dental supply store’s equipment page. Both share the Portuguese word carrinho, which can refer to a cart, a stroller, or similar wheeled equipment.
That matters because it looks like a real ranking in a tracking tool. But no dental supplier is suddenly outranking a stroller brand — the dataset simply got noisy.
Why this is happening
Semrush says this is not an isolated error. Other data providers are seeing the same thing. Industry discussion, including coverage by Search Engine Roundtable, points to a likely driver: Google is trying to limit large-scale data collection for AI systems. Google has not commented publicly.
Semrush is responding on the collection side. Its systems already exclude clearly invalid results before they enter the database. The company has also adjusted data sources, added validation checks that flag potentially inaccurate results, and recollects those results. It says it will keep refining this as search behavior changes.
What to do before you react
If you see unexpected ranking changes, especially for keywords unrelated to your pages, treat them as a data question first. Semrush recommends comparing against your own data, such as Google Search Console.
- Check whether the query actually relates to the page. If the keyword is off-topic, the movement may be noise.
- Compare the same keyword in Search Console before changing content, titles, or links.
- If the anomaly persists, contact Semrush support with the domain and keywords so its team can review the data.
The bigger shift: rankings plus AI answers
Semrush frames this as part of a larger change. Search visibility now spans traditional rankings and AI-generated answers, including Google’s AI Overviews and platforms like ChatGPT. The company says it will keep investing in both.
For marketers, the lesson is broader than one tool. Rank tracking was never perfect, but poisoned SERPs make a trust-but-verify workflow more important. Use ranking tools as a compass, not a photograph. When the compass points somewhere strange, check the actual water before you turn the ship.
Source: Semrush Blog
