Agentic Search

Agentic search is AI that autonomously plans, browses, and synthesizes a multi-step research task — not one answer to one query. How it differs from AI search.

First published: Jun 24, 2026 · Last updated: Jul 15, 2026 · Advanced
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Agentic search is AI that autonomously browses, researches, and synthesizes over minutes — not just answers a single query. The key technical gotcha: agentic browsers spin up real Chrome/Edge VMs and can't be blocked via robots.txt.

TL;DR — Agentic searchAgentic search is an AI system that autonomously plans, runs, and synthesizes a multi-step research or browsing task — dozens to hundreds of searches and real page reads — instead of returning one answer to a single query. All agentic search is AI search; not all AI search is agentic. is the third layer of search (traditional → AI searchAI search uses large language models and retrieval-augmented generation (RAG) to synthesize an answer from multiple sources rather than returning a ranked list of links. Examples include Google AI Overviews, ChatGPT Search, and Perplexity. → agentic): a system that runs a multi-step loop — Plan → Search → Read → Evaluate → re-search → synthesize/act — over minutes, firing 20–160+ queries per session and reading full page content, not cached snapshots. The platforms split into two camps for control purposes. Declared crawlersA crawler — also called a spider or bot — is an automated program that fetches web pages, extracts their links, and queues new URLs to visit. Search engines use crawlers to discover and download content for their index. (Gemini-Deep-Research, Claude-User) respect robots.txt. Agentic browsers (ChatGPT Agent, Project Mariner, Copilot Actions) spin up real Chrome/Edge VMs with no declared bot UA — robots.txt can’t touch them; only server-side controls or the emerging Web Bot Auth RFC can. The payoff: AI-referred traffic converts ~42% better than non-AI, and agentic traffic is the highest-intent slice of that.

Agentic search is a third layer, not a replacement

Current vendor descriptions support multi-step research and tool use, not a universal replacement for retrieval or ranking. Evidence for this claim Deep-research products can perform multi-step web research and synthesize cited results. Scope: Documented product capabilities, not a universal definition or ranking architecture for agentic search. Confidence: high · Verified: OpenAI: Introducing deep research Pipeline diagrams here are explanatory models unless explicitly documented by a provider. Evidence for this claim The term agentic search covers an evolving set of vendor implementations whose tools and behavior can differ. Scope: Editorial synthesis from documented product behavior; implementations and releases may vary. Confidence: medium · Verified: OpenAI: Introducing deep research

The mental model I keep coming back to:

  • Traditional search returns links; the human reads and decides.
  • AI searchAI search uses large language models and retrieval-augmented generation (RAG) to synthesize an answer from multiple sources rather than returning a ranked list of links. Examples include Google AI Overviews, ChatGPT Search, and Perplexity. (the GEOGenerative Engine Optimization (GEO) is the practice of optimizing content and brand presence so AI-powered search engines and assistants — Google AI Overviews, ChatGPT, Perplexity — cite, recommend, or mention you when generating answers. Google's position is that it's still SEO./AEOAnswer Engine Optimization (AEO) is the practice of structuring content so engines deliver it as a direct answer — featured snippets, voice assistants, and AI search — rather than just a ranked link. Coined for voice search in 2018 and revived for the LLM era. Google's position is that it's still SEO. target — AI OverviewsAI Overviews are the AI-generated summary box Google shows above or within its regular search results, written by Gemini models from pages retrieved out of Google's normal Search index. It's a Search feature, not a separate platform or index., ChatGPT answers, Perplexity) returns one answer synthesized from retrieved context.
  • Agentic search breaks a goal into sub-tasks, picks its own tools, reads full pages, iterates on what it learns, and ends in a synthesized report or an action (a purchase, a booking, a form fill).

Semrush put the relationship as well as anyone: “All agentic search is AI search. Not all agentic search is the same thing as AI search.” The short version that sticks — all agentic search is AI search; not all AI search is agentic. None of this replaces traditional SEO. Authority, indexability, and structured dataStructured data is a standardized way of labeling page content (using the schema.org vocabulary in JSON-LD, Microdata, or RDFa) so search engines can understand its meaning. It's not a direct ranking factor — its value is rich results and entity understanding. are still prerequisites; agentic optimization stacks completeness, machine-readability, and entity clarity on top.

How agentic systems actually work

The defining difference from RAGRAG is the retrieve-then-generate pattern behind AI search: the system retrieves relevant passages from an external index at query time, injects them into the model's context, and generates an answer grounded in those sources — without changing the model's weights. or a single retrieval call is that retrieval happens mid-reasoning, on a loop:

Agentic retrieval happens inside the reasoning loop: evaluate what is missing, search again, then synthesize or act.

An agent begins by breaking a goal into sub-tasks. It formulates one or more searches, fetches and reads live sources, and evaluates gaps, conflicts, and evidence. When evidence is missing, it revises the query and loops back to search. Once the task is sufficiently supported, it synthesizes a report or takes an allowed action. This is an explanatory model; products vary and do not all expose or implement every step identically.

Firecrawl describes it as a method where the agent “decides when to search, formulates the query from context, reads actual page content from each result, and evaluates what it foundA 302 (\"Found\") is a temporary redirect: it forwards users to a new URL while telling search engines the original URL should stay in the index. It's a weak canonicalization signal, not the zero-equity dead end of SEO folklore. before deciding whether to synthesize or search again.” The practical consequences:

  • Real-time page reads, not pre-indexedStoring a crawled page in the search index so it can appear in results. Crawled is not the same as indexed — Google selects what to keep, and indexing isn't guaranteed. summaries. Agents fetch and read full live content. Freshness and live availability matter more than for traditional search; a cached snapshot isn’t what they’re working from.
  • Iterative query reformulation. If results are stale or off-target, the agent rewrites the query (e.g. tacking “2026” onto a query when it gets deprecated docs) and goes again.
  • Tool chaining. A single task can combine web search, code execution, file reads, and form submission.
TIP Check which sub-questions your page leaves unanswered

This is a deterministic coverage simulation, not a reproduction of any platform's private agent or ranking system.

Generate a query fan-out and compare its branches with a page or passage using my free Query Fan-Out Simulator Free

  1. Enter the goal-like query an agent would need to research and the page or passage you want to test.
  2. Review uncovered and partially covered sub-queries instead of treating one broad topic match as complete coverage.
  3. Confirm the answer shape and evidence manually; this run uses lexical BM25 and cosine components and does not evaluate embeddings.
The result surfaces which branches are fully covered and which still need a stronger passage or evidence. It does not predict a specific agent's searches.

The completed Query Fan-Out Simulator result contains five sub-queries for technical SEO audit. Two branches show 100 percent term coverage, two show 60 percent, and one shows 75 percent. Each result says to confirm the answer shape and evidence. The result also states that coverage uses lexical BM25 and cosine components only and that embeddings are not evaluated in this run.

How many searches per session

This is not one query. Volume by platform:

ProductSearches per sessionDuration
Perplexity Deep Research20–50 queries2–4 minutes
Gemini Deep Research~80 (standard); ~160 (Max)up to 60 min (most < 20)
OpenAI Deep Researchunspecified; “tens of minutes”10–30+ minutes
Project Marinertask-based browsing (up to 10 parallel tasks)per task
ChatGPT Agentup to ~10 parallel tasksper task

Google’s SAGE research found AI agents take an average of 4.9 steps per query — searching, comparing, and evaluating across multiple sources before delivering a result.

The major agentic platforms

OpenAI — Deep Research + ChatGPT Agent. Deep Research (o3-deep-research / o4-mini-deep-research) is built to “find, analyze, and synthesize hundreds of sources to create a comprehensive report at the level of a research analyst,” and OpenAI warns the requests “can take a long time.” ChatGPT Agent is the successor to Operator — a cloud-hosted Chromium instance that browses the real web and can run ~10 parallel tasks. Its retrieval bots (OAI-SearchBot, ChatGPT-User) are declared; the agentic browser is not.

Google — Gemini Deep Research + Project Mariner. Gemini Deep Research runs an explicit “Plan → Search → Read → Iterate → Output” loop — Google describes it “continuously refin[ing] its analysis, browsing the web by searching and finding interesting pieces of information then starting a new search based on what it’s learned, repeating this process multiple times before generating a comprehensive report.” It has a declared Gemini-Deep-Research user agentA user agent is the HTTP request header a client (browser, crawler, or bot) sends to identify itself. For crawlers, a short user-agent token — a substring of that string — is what robots.txt rules actually target. and respects robots.txt. Project Mariner is the browser-automation agent (up to 10 parallel tasks) — it runs a standard Chrome fingerprint from cloud VMs with no declared bot UA.

Perplexity — Deep Research / Sonar. Perplexity “performs dozens of searches, reads hundreds of sources, and reasons through the material to autonomously deliver a comprehensive report” — 20–50 queries in 2–4 minutes. Its declared PerplexityBot says it respects robots.txt. In August 2025, Cloudflare reported observing undeclared crawlersA crawler — also called a spider or bot — is an automated program that fetches web pages, extracts their links, and queues new URLs to visit. Search engines use crawlers to discover and download content for their index. it attributed to Perplexity reaching content despite no-crawl directives; Perplexity disputed Cloudflare’s account. Separately, Perplexity’s docs say Perplexity-User generally ignores robots.txt because it represents a user-requested fetch.

Anthropic — Claude web search + computer use. Claude-User (real-time user-initiated fetches) respects robots.txt. When Claude runs in computer-use mode it drives a standard browser and emits no declared bot UA — the same agentic-browser pattern as Mariner and ChatGPT Agent.

Microsoft — Copilot + Copilot Actions. Copilot’s underlying web retrieval uses BingbotBingbot is Microsoft Bing's primary web crawler — the bot that discovers, fetches, and renders pages to build the Bing index. That index also powers Yahoo, DuckDuckGo, Ecosia, and Microsoft Copilot, so Bingbot's reach is far wider than Bing's own search-market share., which respects robots.txt. Copilot Actions (agentic browsing) uses a standard Edge/Chromium UA with no declared bot signal — indistinguishable from human browsing at the UA layer.

User agents and the robots.txt gap

This is the part that trips people up, so here’s the whole landscape in one table:

Bot / agentUser agent signalrobots.txtA plain-text file at the root of a host that tells crawlers which URLs they may and may not request. It controls crawling, not indexing — a blocked URL can still be indexed if it's linked from elsewhere.Type
GPTBot…compatible; GPTBot/1.3RespectsTraining
OAI-SearchBot…compatible; OAI-SearchBot/1.3RespectsSearch index
ChatGPT-User…compatible; ChatGPT-User/1.0Unclear since Dec 2025User-triggered
ChatGPT AgentStandard Chrome UA + Signature-Agent headerNo signalAgentic browser
ClaudeBot…compatible; ClaudeBot/1.0RespectsTraining
Claude-SearchBotClaude-SearchBotRespectsSearch index
Claude-User…compatible; Claude-User/1.0RespectsUser-triggered
PerplexityBot…compatible; PerplexityBot/1.0Says yes; Cloudflare disputed complianceSearch index
Perplexity-User…compatible; Perplexity-User/1.0Generally ignoresUser-triggered
Gemini-Deep-Research…compatible; Gemini-Deep-Research; +https://gemini.google/…RespectsDeep-research agent
Google-AgentStandard Chrome UAIgnoresUser-triggered
Bingbot…compatible; bingbot/2.0RespectsSearch / Copilot index
Copilot ActionsStandard Edge/Chromium UANo signalAgentic browser
Project MarinerStandard Chrome UA (cloud VM)No signalAgentic browser

The categories that matter: training crawlers and search-index bots respect robots.txt; user-triggered fetchers vary (OpenAI quietly muddied ChatGPT-User’s position in December 2025); and agentic browsers ignore it by design.

The key gotcha: agentic browsers are unblockable via robots.txt

robots.txt is a directive for crawlers. Agentic browsers — ChatGPT Agent, Project Mariner, Copilot Actions, computer-use Claude — spin up real Chrome or Edge instances inside cloud VMs. They present as standard browsers, declare no bot identity, and are treated as browser proxies rather than crawlers. So:

  • You can block training (GPTBot, ClaudeBot) and search-index bots (OAI-SearchBot, Claude-SearchBot) in robots.txt.
  • You cannot block the agentic browsers there. They simply don’t read it.

The only things that work against the agentic-browser layer are server-side controls (IP-range rules, rate limiting, bot-management at the edge) and the emerging Web Bot Auth RFC — cryptographic agent verification. ChatGPT Agent is already an early signal here: it sends an ed25519-signed Signature-Agent: "https://chatgpt.com" HTTP Message Signature, which is the only reliable server-side identifier for it (in plain analytics it shows up as “direct/(none)” on a direct visit, or “Bing/organic” when it found you via Bing search).

One corollary worth saying out loud: blocking GPTBot does not stop ChatGPT from reading your pages in real time. GPTBot is the training crawler. Deep Research and ChatGPT Agent reach your content through entirely different mechanisms.

What content signals matter for agentic AI

Agents read full pages and evaluate them for completeness, citeability, consistency, and machine-readability. From the research, what actually helps:

  • Comprehensive, single-resource pages. Agents go deep but narrow — they may read 5–10 pages thoroughly rather than skim hundreds. A page that fully answers a topic (and the sub-questions it raises) is far more useful than five thin ones. ALM Corp’s framing: “Structure gives agents stable extraction points — a page with clear headings, labeled sections and consistent formatting is easier to quote accurately.”
  • Well-cited, authoritative, machine-readable content. Agents cross-reference against third-party sources and knowledge bases, so external citations help you clear their trust threshold. This lines up with what I found for AI OverviewsAI Overviews are the AI-generated summary box Google shows above or within its regular search results, written by Gemini models from pages retrieved out of Google's normal Search index. It's a Search feature, not a separate platform or index.: mentions on heavily-linked pages correlate at ~0.70 (Spearman) with AI visibility — the strongest single signal in that study, and a pattern I’d expect agentic retrieval to lean on too.
  • Structured data. JSON-LDJSON-LD (JavaScript Object Notation for Linked Data) is a script-based structured data format, typically paired with the schema.org vocabulary to describe page content for search engines and AI systems. Google recommends it over Microdata and RDFa because it's the easiest format to implement and maintain at scale — but all three work, and structured data isn't a ranking signal. isn’t required for citation, but it improves extraction accuracy — GPT-4 went from 16% to 54% correct responses when content carried structured data in one cited test.
  • Speed. BrightEdge data shows ChatGPT agents abandon slow-loading sites immediately — they have less patience than GooglebotGooglebot is Google's web crawler — the software that fetches pages so Google can index and rank them. It comes in two variants, Googlebot Smartphone (primary, under mobile-first indexing) and Googlebot Desktop, and runs an evergreen Chromium renderer., which extends Core Web Vitals discipline into the agentic context. Content also needs to be reachable without JavaScript execution.
  • Scope and tradeoff clarity. Pages that state who a solution is for, who it’s not for, and the tradeoffs are more useful to an agent building a shortlist than content trying to appeal to everyone.

Why this is worth the effort: conversion quality

The traffic numbers are small but the quality is not. As of March 2026, AI-referred traffic converts about 42% better than non-AI traffic, and AI search traffic converts at roughly 14.2% vs. Google’s 2.8%. Agentic traffic is a subset of AI traffic — and almost certainly the highest-intent slice, because an agent only lands a user on your page after evaluating it against alternatives on the user’s behalf. Being one of the handful of pages an agent reads, and being the one it recommends, is disproportionately valuable.

How to think about it: SEO → GEO → ASO

Treat agentic optimization as a third layer stacked on the first two, not a replacement. The foundations don’t change — authority, indexability, structured data. What’s new on top: comprehensive single-topic resources, ruthless machine-readability, entity clarity, external citations, and the recognition that robots.txt is no longer a complete access-control story. See the Checklists tab for the concrete pass.

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