# Paralax: what changed in AI search engines > Editorially independent AI search research publication from the team behind the Machine Relations Index. Dated reporting on what changed in AI search engines and what it means. Dated briefs on what changed in ChatGPT, Perplexity, Gemini, Google AI Mode and AI Overviews, Claude, Microsoft Copilot and Bing, and AI crawler policy. Each brief links its source where one exists. Editorially independent analysis — no sponsors, nothing sold on this domain. - Publication: Paralax — AI Search Intelligence - URL: https://paralax.ai - Feed: https://paralax.ai/feed.xml - llms.txt: https://paralax.ai/llms.txt ## AI Search Change Log - [ChatGPT](https://paralax.ai/engines/chatgpt) — Latest brief 2026-09-29: [OpenAI's Crawl Bot Jumped 838% While Its Answer Bot Fell 49%: Don't Block OAI-SearchBot Over It](https://paralax.ai/blog/openai-answer-time-fetch-index-crawl-divergence-2026) - Primary source: [developers.openai.com](https://developers.openai.com/api/docs/bots) - [Perplexity](https://paralax.ai/engines/perplexity) — Latest brief 2026-09-22: [Perplexity Citation Change Log: 490 of the Top 500 Domains, Recorded Six Sources Deep](https://paralax.ai/blog/perplexity-citation-change-log-2026) - [Gemini](https://paralax.ai/engines/gemini) — Latest brief 2026-09-28: [Gemini Cited No Source in 51.6% of Its Returned Answer Runs](https://paralax.ai/blog/ai-answer-runs-that-cite-nothing-per-engine-2026) - Primary source: [ai.google.dev](https://ai.google.dev/gemini-api/docs/google-search) - [Google AI Mode](https://paralax.ai/engines/google-ai-mode) — Latest brief 2026-09-24: [Google AI Mode and AI Overviews Share at Least 363 of the Top 500 Sources — and Why We Withdrew the Gap Number](https://paralax.ai/blog/google-ai-mode-ai-overviews-source-divergence-2026) - [Google AI Overviews](https://paralax.ai/engines/google-ai-overviews) — Latest brief 2026-09-24: [Google AI Mode and AI Overviews Share at Least 363 of the Top 500 Sources — and Why We Withdrew the Gap Number](https://paralax.ai/blog/google-ai-mode-ai-overviews-source-divergence-2026) - [Claude](https://paralax.ai/engines/claude) — Latest brief 2026-09-23: [Claude Citation Change Log: 463 of the Top 500 Domains, a Panel the Six-Source Cap Barely Touched](https://paralax.ai/blog/claude-citation-change-log-2026) - [Microsoft Copilot and Bing](https://paralax.ai/engines/copilot) — Latest brief 2026-10-15: [Bing Topics Portfolio Shows Where Rivals Win AI Citations](https://paralax.ai/blog/bing-topics-portfolio-ai-performance-opportunity-queries-2026) - Primary source: [blogs.bing.com](https://blogs.bing.com/webmaster/2026/10/introducing-topics-portfolio-beta-in-ai-performance/) - [AI crawlers and robots](https://paralax.ai/engines/crawlers) — Latest brief 2026-09-29: [OpenAI's Crawl Bot Jumped 838% While Its Answer Bot Fell 49%: Don't Block OAI-SearchBot Over It](https://paralax.ai/blog/openai-answer-time-fetch-index-crawl-divergence-2026) - Primary source: [developers.openai.com](https://developers.openai.com/api/docs/bots) [Full change log](https://paralax.ai/engines) ## Latest Intel - [Bing Topics Portfolio Shows Where Rivals Win AI Citations](https://paralax.ai/blog/bing-topics-portfolio-ai-performance-opportunity-queries-2026) — Bing now lists the AI queries where other sites are cited and yours is not, but its Sites Cited column counts breadth, not how concentrated - [OpenAI's Crawl Bot Jumped 838% While Its Answer Bot Fell 49%: Don't Block OAI-SearchBot Over It](https://paralax.ai/blog/openai-answer-time-fetch-index-crawl-divergence-2026) — If OAI-SearchBot traffic spiked this month, blocking it is the wrong move: that costs ChatGPT search eligibility. Five weeks of logs across - [Gemini Cited No Source in 51.6% of Its Returned Answer Runs](https://paralax.ai/blog/ai-answer-runs-that-cite-nothing-per-engine-2026) — The Machine Relations Index now publishes per-engine run denominators. Perplexity cited a source in 99.97% of returned runs. Gemini cited on - [ChatGPT Citation Support Rate Holds at 5x the Sample](https://paralax.ai/blog/chatgpt-citation-support-rate-holds-scale-2026) — Machine Relations' live Fidelity cohort has now graded 8,258 ChatGPT citations at 53.4% supported, confirming the September frozen-sample ra - [Nine in Ten AI Citations Never Name the Source](https://paralax.ai/blog/ai-citations-that-never-name-the-source-2026) — Across 14,447 readable citations in four AI engines, the cited source's name reached the answer text 8.6% of the time. The rate splits by en - [Two of Three Gap-Free AI Engines Keep Exclusive Sources at Volume](https://paralax.ai/blog/cross-engine-exclusivity-conditioned-2026) — The Machine Relations Index's raw exclusivity share for all six AI answer engines, then the same number conditioned on citation volume. Amon - [Google AI Mode and AI Overviews Share at Least 363 of the Top 500 Sources — and Why We Withdrew the Gap Number](https://paralax.ai/blog/google-ai-mode-ai-overviews-source-divergence-2026) — Our 67-domain reach gap between Google AI Mode and AI Overviews is withdrawn: the instrument had collection gaps. The surfaces share 363+ of - [What Counts as One Domain? The Subdomain Rule the Machine Relations Index Publishes, Tested on 23,280 Rows](https://paralax.ai/blog/domain-counting-rule-ai-visibility-index-audit-2026) — Every AI visibility tool reports domains cited. Almost none tells you whether learn.microsoft.com counts as microsoft.com. The Machine Relat - [Claude Citation Change Log: 463 of the Top 500 Domains, a Panel the Six-Source Cap Barely Touched](https://paralax.ai/blog/claude-citation-change-log-2026) — A dated record of what Claude cites. Entry one: Claude reaches 463 of the 500 most-cited domains, second only to Perplexity among the engine - [Perplexity Citation Change Log: 490 of the Top 500 Domains, Recorded Six Sources Deep](https://paralax.ai/blog/perplexity-citation-change-log-2026) — A dated record of what Perplexity cites. Entry one: Perplexity reaches 490 of the 500 most-cited domains, the widest head overlap of any eng ## The beat The beat is machine-mediated discovery. Paralax reports on the engines that retrieve, cite, and rank sources — Google AI Mode and AI Overviews, Perplexity, ChatGPT search, Claude, Gemini, Microsoft Copilot and Bing — and on the infrastructure around them: crawler policy, robots rules, citation architecture, and answer-engine measurement. Each dispatch asks what changed in how machines find information, and what that change does to publishers, brands, and the public record. A brief ships when a change is verified, not to fill a day. Coverage is dated, sourced, and written so a person and an agent can use the same page. ## How to read this site This homepage is the desk, not a product landing page. Read it as a publication: the change log by engine, the latest Intel, the beat, and the rules for citing what you find here. ### The change log Each engine has one change-log page listing every brief about it, newest first, with its date and the change in one line. Each brief links its source where one exists. ### The Intel stream The Intel stream is the dated archive. Each article leads with a claim, names its sources, and can be opened as HTML or as a markdown twin at the same path plus .md. The full index lives on the Intel page. ### Machine-readable twins Agents should not reconstruct this site from chrome. Send Accept: text/markdown to any canonical URL, or fetch the .md alternate. Start a crawl from llms.txt or machine-manifest.json. Those files describe an editorial publication, not a software product.