Is Q-Star the Next PageRank? What Google's Antitrust Trial Revealed

Internal documents and testimony from the U.S. Department of Justice's antitrust trial against Google reveal that Google uses a previously undisclosed Q* metric to assess website trustworthiness and quality. According to Google's own trial exhibits, Q* is "an internal metric that assesses the trustworthiness of a whole website (most often the domain)". This provides insight into Google's ranking algorithm.

What Is Q*?

Q* was identified during the DOJ proceedings, described in trial exhibits as an internal Google score for content quality and trust. In a January 2025 call transcript excerpt submitted as evidence, Google engineers explicitly identified Q* as "Google's measure of quality of a document."

Q* is a proprietary quality score that Google computes for pages and likely aggregates at the domain level. Unlike PageRank, which anyone could once check through Google's toolbar, Q* operates entirely internally. The SISTRIX analysis of trial evidence describes it as an internal metric focused on site trustworthiness rather than popularity.

Q* differs from PageRank in its focus. While PageRank measured a page's authority through its backlink profile, Q* appears to evaluate content quality and trustworthiness through different criteria. It might consider factors like content comprehensiveness, factual accuracy, or domain authority in ways that remain opaque to outsiders.

The trial materials also revealed that Q* is deliberately engineered rather than machine-learned. Google told the court that most ranking factors are still hand-crafted by engineers, with only a few major signals derived from machine learning models. This means Q* isn't some accidental byproduct of AI training—it's an explicit score carefully built into Google's ranking infrastructure.

Q* in the DOJ Antitrust Trial

The existence of Q* came to light through internal "interview notes" and exhibits Google was required to produce during the antitrust proceedings. One key exhibit from a January 31, 2025 interview with Google search engineers explicitly names Q* alongside other known ranking factors.

When Google executives like search VP Pandu Nayak testified publicly, they avoided mentioning Q* or other proprietary signals. They discussed visible ranking factors—content, links, user behavior—and the well-known "ABC signals" (Anchors, Body, Clicks). The information about Q* came from the internal documents submitted as evidence, not from any on-the-record statements.

These documents indicate Q* as a significant component of Google's quality assessment system. One internal source cited in the trial described it as playing an "extremely important role" in rankings. The fact that it appears in court materials demonstrates its relevance to Google's ranking system.

Google's History of Denying Site-Wide Scores

The revelation of Q* is particularly notable given Google's long history of publicly denying the existence of any domain-level authority or trust scores.

In October 2016, Google Search Advocate Gary Illyes stated on Twitter: "we don't really have 'overall domain authority'". Around the same time, John Mueller from Google's Search Relations team told a Webmaster Hangout that "we don't have anything like a website authority score". Mueller reiterated this position in June 2019, saying "In general, Google doesn't evaluate a site's authority... That's not something we would be applying here."

Google's Danny Sullivan has similarly downplayed the concept of any global site score in various SEO myth-busting posts and tweets. Official Google documentation, including the Search Quality Rater Guidelines, emphasizes E-A-T (Expertise, Authoritativeness, Trustworthiness) assessments but never mentions any numeric site-quality or trust score.

The DOJ trial documents directly contradict these statements. Not only do they confirm Q* as a site-level quality metric, but leaked internal API documentation also reveals a computed feature called "siteAuthority" that is applied as part of Google's quality signals. As SEO analyst Mike King noted after reviewing the leaked documents: "Google has a feature they compute called 'siteAuthority'... We do know definitively that it exists and is used in the Q* ranking system."

This contradiction between Google's public statements and internal reality isn't entirely surprising. Tech companies often keep algorithmic details confidential for competitive reasons. However, the gap between "we don't have anything like a website authority score" and the documented existence of Q* and siteAuthority is striking.

How Q* Relates to PageRank and Other Signals

Understanding Q*'s role requires seeing how it fits into Google's broader ranking ecosystem. The trial exhibits revealed that Google's ranking score combines several high-level buckets: the ABC signals (Anchors, Body, Clicks), Navboost (click data), and Q*.

This suggests a system where PageRank (part of the "Anchors" signal) provides one perspective on authority through links, while Q* adds a layer of quality assessment that operates independently. A site might accumulate thousands of backlinks and achieve high PageRank, yet still receive a poor Q* score if its content lacks depth or reliability.

It's also important to distinguish Q* from E-E-A-T (Experience, Expertise, Authoritativeness, Trustworthiness). While E-E-A-T represents guidelines for human quality raters, Q* is an automated algorithmic signal. There's no indication in the trial documents that Q* directly implements E-E-A-T, though it likely captures similar quality dimensions through its own proprietary calculations.

These signals work together in Google's ranking system. Where PageRank measured authority through links, Q* appears to encode Google's assessment of quality—a score that can't be influenced through traditional link building or content optimization tactics. The irony is that while Google publicly promoted E-E-A-T as a conceptual framework without scores, they were simultaneously using Q* as an actual scored metric behind the scenes.

What This Means for the Future of Search

The confirmation of Q*'s existence provides new information about search ranking evolution. If PageRank represented an approach to authority through linking, Q* appears to represent a different approach focused on quality assessment.

For website owners and SEO professionals, the implications are clear. Unlike PageRank, which could be influenced through link acquisition strategies, Q* remains completely opaque. There's no Q* score in Search Console, no public formula to optimize against, and no documented path to improvement beyond creating high-quality content.

This opacity appears intentional. As the trial documents suggest, Google views Q* as a competitive advantage, a proprietary signal that helps maintain search quality while resisting manipulation.