BacklinkBees Team · Jul 9, 2026 (updated Oct 11, 2026) · 22 min read
Ranking a website in 2026 no longer means satisfying a single algorithm. It means clearing a distributed pipeline of ingestion, quality gating, and behavioral re-ranking, then getting picked up and cited correctly by a second layer of AI answer engines running on top of that index.
Leaked API documentation, antitrust trial exhibits, and Google's own patents have made parts of that pipeline visible for the first time. One caution applies throughout: the leak names components and attributes, but it does not show how they are weighted or whether each is still in use.
This guide says which claims are documented and which are analysts' readings, then covers what to do about it.
How search actually works
Trawler, Mustang, Q*, and NavBoost
How AI engines cite you
ChatGPT Search, Perplexity, and Google AI Mode
E-E-A-T in the leaked docs
Author attributes and YMYL classifiers
Information Gain
The patent, and a way to score it
Entity SEO & embeddings
WebRef, siteRadius, and knowledge graphs
Brand authority & AI recs
Why AI models cite brands, not just links
NavBoost & Core Web Vitals
Click data, Chrome data, and the UX thresholds
Backlinks in 2026
Seed distance and source-page quality
Technical SEO for AI bots
robots.txt, SSR, and schema markup
AI content policy
What Google's policies say, and what they don't
The next 3 to 5 years
Agentic search and personalized results
The priority framework
What to fix first, and how sure we are
Myth vs reality
What Google says versus what the leak lists
By business size
A playbook for local, SaaS, and enterprise
Frequently asked questions
9 direct answers to common questions
Glossary of key terms
Every acronym and attribute, defined
Google's search architecture is a pipeline of crawling, indexing, scoring, and re-ranking systems, not one static calculation. The names below come from the Content Warehouse API documentation that leaked in 2024, as analyzed by Mike King at iPullRank.
Web discovery begins with the Trawler crawler, which fetches pages and routes them to Alexandria, the core indexing system, which builds the CompositeDoc, the record for an indexed URL. Nested inside it, the PerDocData model holds page-level quality and classification attributes.
The documentation also describes index tiers: the most important documents are kept on the fastest storage and the rest on slower tiers. A link attribute called sourceType records which tier the linking page sits in, and King reads that as links from higher-tier pages being worth more.
For the full 28-year history of how this pipeline was built, see our complete timeline of Google's search algorithm.
At query time, Mustang is the primary scoring, ranking, and serving system. A DOJ trial exhibit, the notes of a February 2025 call with Google engineer HJ Kim, describes the main scores. Topicality (T*) combines three fundamental signals: anchors (links), body (terms in the document), and clicks (how long a searcher stayed before returning to the results). Quality (Q*) is described as largely static and tied to the site more than the query.
PageRank is described as a single signal relating to distance from a known good source, used as an input to the quality score. The leaked documentation lists siteAuthority as an attribute "applied in Qstar", next to demotion fields such as pandaDemotion and navDemotion.
Many analysts read that as a site-level quality gate. The documents show the attribute exists, not how it is computed or how much it counts.
Initial scores are then adjusted by Twiddlers, re-ranking functions that run after the primary scoring. NavBoost is the click-based one. Trial testimony from Google's Pandu Nayak, as reported by iPullRank, put its window at about 13 months of click data, down from 18. FreshnessTwiddler re-ranks documents based on freshness, and QualityBoost is listed among the boost functions. A separate attribute, contentEffort, is described in the documentation as an LLM-based effort estimate for article pages.
The pipeline as analysts reconstruct it: discovery, indexing, scoring, a site-level quality score, then click-based re-ranking.
AI search platforms use retrieval-augmented generation (RAG): they retrieve web documents, extract the relevant passages, and generate an answer with citations. What you can control starts with the crawler. OpenAI's documentation says OAI-SearchBot is used to surface websites in ChatGPT's search features, and that sites opted out of it will not be shown in ChatGPT search answers. GPTBot is a different crawler that collects content for model training, and each setting is independent of the others.
Perplexity documents the same split: PerplexityBot surfaces and links sites in its search results, while Perplexity-User fetches a page when a user's question calls for it. Google's guidance is that a page must be indexed and eligible to be shown with a snippet to appear in its generative AI features.
What happens after retrieval is not documented by the vendors, so treat the following as one study's finding. In July 2026 RESONEO analyzed 1,249 ChatGPT answers and found a result_source field with four values: labrador, bright, oxylabs, and serp.
RESONEO reads labrador as OpenAI's in-house index, bright as scraped Google results, and oxylabs as a news pipeline. It also reports that the field disappeared from responses on 21 July 2026. Those labels are inferences from network data, not anything OpenAI has confirmed, and they can change without notice.
| Feature | Google AI Mode |
|---|---|
| Primary retrieval | Query fan-out: concurrent related queries over the Search index |
| Search crawler to allow | Googlebot |
| Eligibility rule | Page must be indexed and eligible to show with a snippet |
| Link authority | Not published for AI features |
| Top recommendation factor (First Page Sage) | Gemini: authoritative list mentions, 49% |
Our complete AEO checklist turns this section into steps you can work through.
If AI crawlers can't read your page, nothing else on this list matters.
Experience, Expertise, Authoritativeness, and Trust (E-E-A-T) is the framework Google gives its human quality raters. Their ratings evaluate search results and do not rank pages directly. The guidelines' change log records a January 2025 update that revised the Lowest and Low quality sections to align with Google's spam policies.
The current edition defines generative AI, tells raters to give the Lowest rating when they strongly suspect scaled content abuse, however the pages were made, and treats filler as a poor user experience. Trust is the central pillar, and experience, expertise, and authority support it.
The leaked documentation suggests related machine signals exist. PerDocData lists authorObfuscatedGaiaStr, an obfuscated identifier for a document's author, and iPullRank notes that Google stores authors as text and has an isAuthor attribute for entities.
PerDocData also lists ymylHealthScore and ymylNewsScore, described as scores from Your-Money-or-Your-Life (YMYL) health and news classifiers. The documentation does not say how any of these feed ranking. The practical reading is modest: Google can tell who wrote a page and whether its topic is sensitive, so make both easy to verify.
Every article should carry a clear byline linked to a dedicated author profile with real credentials, portfolio links, and social profiles marked up with JSON-LD sameAs schema.
Use natural, first-person phrasing that signals real hands-on experience, paired with custom photography, unique screenshots, or raw video walk-throughs.
Link out to primary scientific research, government data, or academic publications, and publish a transparent editorial and fact-checking policy.
Generative tools have made paraphrased text trivial to produce at scale, which is why Information Gain matters. The term comes from a Google patent, "Contextual estimation of link information gain", granted in June 2022. It describes scoring how much additional information a document offers beyond the documents a searcher has already been shown, and using that score to rank or demote results.
A patent shows what Google has considered, not what is running in production, and Google has not confirmed using it.
IG(T | X) = H(T) − H(T ∩ X)
Our illustration, not a formula from the patent. T = your document. X = the documents already ranking. H = information content. The patent describes a machine-learning model, with no published equation.
The idea is simple. If a document only rewrites the pages that already rank, the overlap is nearly total and it adds almost nothing. If it brings its own statistics, benchmarks, or expert quotes, the overlap shrinks and the page has something a searcher, or an AI answer, can't get elsewhere. To audit content against this standard, we use a five-part rubric of our own:
| Dimension | Points |
|---|---|
| Proprietary data | 0 to 2 |
| First-hand evidence | 0 to 2 |
| Original framework | 0 to 2 |
| Expert attribution | 0 to 2 |
| Freshness hook | 0 to 1 |
A page that only paraphrases the current top results gives a searcher nothing new.
Search engines work with entities (people, companies, products, places) and the relationships between them, not only with keywords. In the leaked documentation, Google's WebRef system annotates the entities found in a page's text.
Analysts point to attributes such as confidenceScore (how certain the system is that a phrase is a known entity), topicalityScore (how relevant that entity is to the page), and segmentMentions (the entity's mentions across the document).
Entities connect into subject-predicate-object statements such as [ChatGPT] → is_developed_by → [OpenAI], which is how a knowledge graph stores facts.
The documentation also references page-level and site-level embeddings, which are numeric representations of what a page or a whole site is about. Two attributes build on them. iPullRank describes siteFocusScore as how much a site sticks to a single topic, and siteRadius as how far a page goes outside that core topic.
Analysts read this as a reason to keep a site on-topic. The documents do not show a demotion for drifting, so treat that part as a reasonable inference.
siteRadius, as analysts read it: how far each page sits from the site's core topic.
Click data is one of the better-documented parts of the system. In the DOJ exhibit, Google engineer HJ Kim lists clicks as one of three fundamental signals. The leaked documentation lists the click attributes NavBoost works with, including goodClicks, badClicks, and lastLongestClicks.
Analysts read these as clicks that satisfied the searcher, quick returns to the results page (pogo-sticking), and the last, longest click of a session. Chrome is less clear. The documentation lists chromeInTotal, described as site-level Chrome views, and the DOJ exhibit refers to a popularity signal that uses Chrome data. Neither source says how that data is weighted.
The safe conclusion is that what visitors do after the click matters, so a page should load quickly and answer the query it ranks for. Core Web Vitals are Google's public measure of that experience. A page passes when it meets all three thresholds:
| Metric | Threshold |
|---|---|
| Interaction to Next Paint (INP) | Under 200 milliseconds |
| Largest Contentful Paint (LCP) | Under 2.5 seconds |
| Cumulative Layout Shift (CLS) | Under 0.1 |
Links still count, and the evidence points to where they come from mattering more than how many there are. In the DOJ exhibit, HJ Kim describes PageRank as a single signal relating to distance from a known good source, used as an input to the quality score.
The leaked documentation has a matching attribute, homepagePagerankNs, which Mike King reads as the "nearest seed" version of PageRank. Under that reading, Google starts from a set of trusted seed sites and measures how many link hops separate a page from them.
Pages a few hops from a trusted source inherit more trust than pages far out in the graph. Google has not published which sites are seeds.
The leaked documentation also shows Google recording the quality of the page a link comes from. The sourceType attribute on an anchor marks whether the linking page sits in the high, medium, or low quality part of the index.
A separate field, anchorMismatchDemotion, points to a demotion when a link doesn't match the page it points to. That fits the reason a direct, reciprocal link exchange still carries risk today: it isn't the existence of a link that gets flagged, it's the pattern the link leaves behind.
For the kinds of pages that attract links on their own, see how to get backlinks without outreach.
One email when we publish a new link-exchange or SEO guide. No spam, unsubscribe anytime.
If crawlers can't reach and parse a page, it stays invisible to search engines and AI answer engines alike. A common mistake is blocking AI search bots by accident, through a broad robots.txt rule or a CDN or firewall setting that blocks AI bots by default. Each AI company runs separate bots for search and for model training, and robots.txt controls them independently.
Per OpenAI's documentation, OAI-SearchBot decides whether you can appear in ChatGPT search, while GPTBot only governs training. Anthropic splits Claude-SearchBot (search) from ClaudeBot (training) the same way. To be citable, allow the search bots:
# Google Search, including AI Overviews and AI Mode
User-agent: Googlebot
Allow: /
# ChatGPT search results (OpenAI's search bot)
User-agent: OAI-SearchBot
Allow: /
# Perplexity search results
User-agent: PerplexityBot
Allow: /
# Claude search results (Anthropic's search bot)
User-agent: Claude-SearchBot
Allow: /
# Training crawlers are a separate decision.
# GPTBot (OpenAI) and ClaudeBot (Anthropic) collect content for model
# training. Allowing or blocking them does not change whether the
# search bots above can surface your pages.To check your own site, open yourdomain.com/robots.txt and look for a Disallow rule under any of those four names, or under User-agent: *. OpenAI notes that a robots.txt change can take about 24 hours to take effect.
Rendering is the second thing to check. Google can render JavaScript, but don't assume AI crawlers will. If pricing, specifications, or key facts load only after client-side rendering, a bot that reads the raw HTML never sees them.
Server-side rendering (SSR) or static site generation (SSG) puts that content in the initial HTML response. View the page source, not the inspector, and confirm the text is there. Structured data then describes that content in a machine-readable way.
Google says it isn't required for its generative AI features and that no special markup is needed, but it still supports rich results and makes clear who you are. These are the types worth having in JSON-LD:
Explicitly defines your brand and its authors, linking them to verified profiles via sameAs to build entity trust.
Describes question-and-answer pairs on the page in a machine-readable way. It is descriptive markup, not a shortcut: Google says structured data isn't required for its generative AI features.
Maps Name-Address-Phone details and geographic coordinates directly to Google's local entity graph.
Describes steps or product details such as price and availability in a structured form that search and shopping systems can read.
Google's official guidelines state that appropriate use of automation or AI generation doesn't violate its policies, provided the content is created primarily to help people rather than manipulate rankings. If a site uses AI to mass-produce low-effort pages mainly to capture search traffic, that is scaled content abuse under Google's spam policies, and the site can rank lower or be removed from results.
Be wary of claims that a specific update added an "AI detector". Google's Search Status Dashboard records the March 2026 core update as rolling out from March 27 to April 8, 2026, and says nothing about AI content or any named model.
What Google has put in writing is narrower. Its guide to generative AI features says content made with AI tools must still meet the Search Essentials, and that creating many pages mainly to manipulate AI responses violates the scaled content abuse policy.
The quality rater guidelines add that such pages deserve the Lowest rating no matter how they were created.
To scale content responsibly, use a hybrid model: let generative tools cluster topics and draft outlines, then require a human subject-matter expert to review and edit every draft, integrating proprietary data, case studies, first-person insight, and verifiable quotes. Avoid publishing automated translations or mass keyword variants without manual review, so every page serves a clear, real user intent.
As AI models develop agentic capabilities, queries are shifting from informational lookups to task execution. Agentic search tools can autonomously browse the web, parse multiple sources, and execute multi-step processes like booking flights, purchasing products, or compiling market intelligence on a user's behalf. SEO strategies need to optimize a brand's technical structure for these automated agents, not just for human screen layouts.
Search behavior is also diversifying away from a single web-text input. Searchers increasingly use image search to search by photo, and use video platforms directly. AI models work across text, images, and video, so a useful video that answers the question is another way to be found. Published figures on how often AI engines cite video sites vary widely between studies, so we don't quote one here.
Finally, expect highly personalized context graphs to replace identical results for every user. With permission, models like Gemini can draw on email, cloud storage, calendar events, and browsing history to understand intent in real time, meaning search results and citations get personalized around a specific workflow, prior searches, and immediate location context.
Ranking factors don't carry equal weight, and nobody outside Google knows the real weights. This framework is our own ordering. Each row says what the evidence is, so you can judge how much to trust it:
| Ranking factor | Business impact |
|---|---|
| AI bot crawlability | Critical, a hard requirement for AI citations (documented by OpenAI, Anthropic, and Perplexity) |
| Information Gain | High, our judgment (based on a Google patent, not a confirmed factor) |
| NavBoost interaction | High (click data confirmed in DOJ testimony) |
| siteAuthority (Q*) | High (listed in the leak, weight unknown) |
| Topical focus | Medium to high (listed in the leak, weight unknown) |
| Core Web Vitals | Medium (thresholds documented by Google) |
| Multimodal assets | Medium, our estimate |
As an organization's search strategy matures, its focus, technical actions, and content standard shift through four stages:
| Maturity stage | Primary focus |
|---|---|
| Stage 1: Foundational | Exact-match keywords, basic metadata |
| Stage 2: Topical | Subject clustering, topical authority |
| Stage 3: Behavioral | NavBoost engagement, mobile UX |
| Stage 4: Semantic | Entity-relationship mapping, AI visibility |
Every layer below reinforces the one above it. Skipping the foundation to chase AI readability doesn't work, because a technically broken site never earns the chance to be judged on its content.
Google's public statements have often been simpler than the systems behind them. The left column paraphrases positions Google representatives have taken over the years, and the middle column shows what the leaked documentation and DOJ exhibits list. Read it with the same caveat HJ Kim gave the DOJ: the leak named components of the ranking system, but not the curves and thresholds that decide how they are used.
| Common public position | What the documents list |
|---|---|
| Domain authority isn't a ranking signal. | The leaked documentation lists siteAuthority within CompressedQualitySignals, described as "applied in Qstar". How it is computed is not shown. |
| Clicks and engagement don't directly influence rankings. | DOJ testimony described NavBoost as using about 13 months of click data, and the leak lists goodClicks, badClicks, and lastLongestClicks. |
| New sites aren't put in a sandbox. | PerDocData lists hostAge, which iPullRank quotes as used "to sandbox fresh spam in serving time". |
| Chrome data isn't used for ranking. | The leak lists chromeInTotal, described as "site-level Chrome views", and a DOJ exhibit mentions a popularity signal that uses Chrome data. |
The right priority also depends on your business model. Here's how the primary quality metric, biggest technical risk, and target off-page link differ by site type:
| Site type | Quality metric |
|---|---|
| SaaS | OriginalContentScore |
| E-commerce | clutterScore |
| Local business | GBP reviews & local schema |
| Publisher | contentEffort & Information Gain |
| B2B enterprise | siteAuthority (Q*) |
Claim, verify, and actively update your GBP listing. It's a primary source for local entity results and map-pack queries.
Keep your Name, Address, and Phone details identical across your site, GBP, and third-party directories, marked up with local business and geo-coordinate schema.
Create dedicated pages or FAQ sections addressing hyper-local customer questions, giving scannable context for local and conversational queries.
Ensure core pages, pricing tables, product features, and reviews are rendered server-side so AI crawlers can actually parse them.
First Page Sage's study ranks authoritative list mentions as the top factor in ChatGPT's recommendations. Earn a place on independent comparison and review sites on the merits of the product.
Structure key service and landing pages with answer-first formats, giving a concise definition in the first three lines for automated citation extraction.
Prune, merge, or noindex low-performing, off-topic pages that raise your siteRadius or dilute your siteFocusScore.
Standardize your organization's entity mapping across all global properties, connecting executive profiles with explicit JSON-LD.
Require proprietary data, expert quotes, and first-hand screenshots in every article before it can be approved for publication.
Information Gain is a concept from a Google patent granted in 2022. It describes scoring how much new information a document adds beyond the documents a searcher has already seen. Google has not confirmed how, or whether, the score is used in ranking, so treat it as a useful standard for original content and not as a published ranking factor.
Google has publicly said it doesn't use a single third-party domain authority metric, and that's true in the sense of tools like Domain Rating or Domain Authority scores. But the leaked Content Warehouse API documentation lists an attribute called siteAuthority inside CompressedQualitySignals, described as "applied in Qstar", and a Google engineer told the DOJ that the Q* quality score is largely static and tied to the site more than the query. The documentation does not show how the attribute is calculated or weighted.
Click data does. DOJ antitrust testimony described NavBoost as a system that uses about 13 months of search click data, and a Google engineer listed clicks as one of three fundamental ranking signals. For Chrome specifically, the evidence is thinner: the leaked documentation lists chromeInTotal, described as site-level Chrome views, and a DOJ exhibit refers to a popularity signal that uses Chrome data. Neither says how much weight it carries.
Google has denied a formal probationary sandbox, but the leaked PerDocData module contains a hostAge attribute. Mike King's analysis at iPullRank quotes its description as being used "to sandbox fresh spam in serving time". That points to age-based handling of suspected spam, not proof that every new site is held back. In practice, most new domains take time to rank because they have few links and little history.
Traditional SEO optimizes for ranking in a list of blue links. Answer Engine Optimization (AEO) formats content to be extracted as a direct answer by voice assistants and featured snippets. Generative Engine Optimization (GEO) goes further, optimizing content so AI systems like ChatGPT Search, Perplexity, and Google AI Mode can synthesize it into a generated, cited answer.
They're changing it, and how far is still unsettled. What Google does state is that its AI features draw on the same Search index: to appear as a supporting link, a page must be indexed and eligible to be shown in Google Search with a snippet. Being crawlable and indexed is still the prerequisite for being cited by the AI layer on top.
Google's official policy is that appropriate use of automation doesn't violate its guidelines, provided the content is created primarily to help people. What its spam policies prohibit is scaled content abuse: producing many pages mainly to manipulate rankings, however they are made. AI-assisted content that a human expert has reviewed and enriched with original data or experience is not the target.
Yes. A Google engineer told the DOJ in 2025 that anchors (links) are one of three fundamental signals, and that PageRank relates to distance from a known good source and feeds the quality score. The leaked documentation also lists a sourceType attribute that records the quality of the page a link comes from, and an anchorMismatchDemotion field. Where a link comes from appears to matter more than how many you have.
Start with access, because it is the only hard requirement. A page that search bots can't crawl can't be cited: OpenAI states that sites opted out of OAI-SearchBot will not be shown in ChatGPT search answers. Once bots can reach server-rendered content, work on Core Web Vitals and answer-first formatting. Those improve the experience, but they don't decide eligibility.
Every acronym and internal attribute referenced above, in one place.
More of the pipeline can be mapped now. The weights are still hidden, but nothing in the documents rewards manufactured signals over a useful site.
The crawler that puts you in ChatGPT search isn't GPTBot, and Google says llms.txt does nothing for it. Here's the full AEO checklist, from crawl access to measurement, built on what the platforms actually document.
By BacklinkBees Team
94 percent of blog posts earn zero backlinks, and only 8.5 percent of outreach emails get a reply (Backlinko). Here's how to earn links passively instead, and what's actually true about AI citations now.
By BacklinkBees Team
From a Stanford research paper to an AI-native ranking engine: 28 years of Google algorithm updates, mapped to what each one means for link builders.
By BacklinkBees Team
BacklinkBees verifies metrics live, vets every publisher, and blocks reciprocal link patterns automatically. Link Exchange is free for your first 3 months.