ChatGPT Search Uses Site-Specific Queries After GPT-5.6 Rollout
Tracking data from Promptwatch shows the share of ChatGPT Search queries containing the site: operator jumped from under 0.5% to 16-17% around August 8, coinciding with OpenAI's GPT-5.6 update.
👁 117 reads
Tracking data published by GEO analytics firm Promptwatch shows that the percentage of ChatGPT Search fanout queries containing the site: operator jumped from a range of 0.3%-0.5% to 16-17% on August 8, 2026 - a change consistent with OpenAI’s GPT-5.6 rollout earlier that month.
- The share of ChatGPT Search fanout queries using the site: operator jumped from under 0.5% to 16-17% on August 8, per Promptwatch tracking data.
- The shift aligns with OpenAI's August 6 announcement of a GPT-5.6 Sol update for Plus and Pro users promising more reliable facts and focused answers.
- Promptwatch also reported on August 18 that ChatGPT appeared to have greatly reduced the likelihood of Reddit being used in those site-targeted searches.
Promptwatch, which operates in the emerging field of Generative Engine Optimization (GEO) - effectively SEO for chatbot responses - uses automation to track how products like ChatGPT, Claude and Gemini respond to prompts at scale. Its data showed the site: operator share dipped briefly to 0.15% on August 3-5, a pattern the firm described as consistent with a staged rollout or pre-launch experiment, before the sharp rise on August 8.
The timing corresponds to an announcement OpenAI made on August 6 for Plus and Pro users: “For Plus and Pro users, we’re updating GPT-5.6 Sol in Chat to be more reliable with facts and provide more focused answers.” OpenAI did not describe the search mechanism in detail.
Developer Simon Willison, who surfaced the Promptwatch findings, noted that OpenAI actively obscures its system prompts, making the internal implementation difficult to verify. Based on his own testing, he believes the current search tool uses a structure closer to search(query, recency, domains) than a direct site: operator instruction - but he could not confirm this from any leaked system prompt.
A follow-up Promptwatch report on August 18 added another signal: ChatGPT appeared to have significantly reduced the likelihood of Reddit appearing in those domain-targeted searches, though whether this reflects an explicit system prompt instruction remains unconfirmed.
For developers and content teams building on or optimising for AI-powered search, the shift matters in concrete ways. If ChatGPT is now routinely scoping searches to specific domains, the domains it chooses - and those it deprioritises, like Reddit - will directly shape which sources get cited in answers. Site-level technical hygiene, crawlability and structured content become more consequential, while visibility in user-generated or forum-style communities may count for less in AI-generated responses than it once did.
Google · Your sourcesQuantslant higher in your Google - one clickAdd to preferred sources →
More on this from QUANTSLANT
ai tools·ChatGPT gets Apple Messages plug-in that can draft and send textsOpenAI has launched an Apple Messages plug-in for ChatGPT that lets users read, search, draft, and send iMessages directly through the chatbot.