Trust on First Use (TOFU) is a crucial metric employed by Google to evaluate the trustworthiness and quality of websites or content without relying on prior interactions or historical data. This approach is particularly significant for new sites or content about which Google has little to no information. The concept of TOFU is analogous to trust models in cybersecurity, where initial trust is established through various signals and assessments in the absence of previous interaction data.
How TOFU Works
The primary objective of TOFU is to provide an initial trust assessment for content, helping Google determine its reliability and quality when there’s no historical user interaction data or established reputation. TOFU serves as a quality predictor at both the site and URL levels, evaluating the trustworthiness and quality of websites and URLs during their first appearance in search results.
Metrics and Signals Used in TOFU
TOFU utilizes a combination of signals to form a quality and trust assessment, including:
- Site Characteristics (e.g., site quality standard deviation, link-out scores)
- Content Quality (e.g., article scores, very low quality scores)
- Trust and Authority Signals (e.g., SpamBrain LAVC score)
- Technical and Metadata Factors (e.g., encoding scores, SiteLinkOut)
- Site and URL Level Predictions (e.g., Chard and Keto scores, Normalized Site Reliability)
Site Characteristics:
- Site Quality Standard Deviation: Measures the variability in quality across different pages of a site, indicating its consistency.
- Link-out Scores: Evaluates how the site links to other websites, helping Google understand the site’s relevance and authority.
- Clutter Scores: Measures the site’s layout and design, determining if it contains spam elements.
- Impressions: Measures how often the site appears in search results, even if it hasn’t been clicked yet.
- Language: The primary language of the site, ensuring its relevance to the intended audience.
Content Quality:
- Article Scores: Measures the quality of written content based on factors such as originality and usefulness.
- Very Low Quality (VLQ) Scores: Flags content that is particularly low quality, such as duplicated or spam-like material.
- Generated Content (Racter) Scores: Determines if the content is automatically generated to ensure it doesn’t overly rely on automation.
Trust and Authority Signals:
- SpamBrain LAVC Score: Detects whether a site engages in spam-like activities.
- COVID Authority Signal: During the COVID-19 pandemic, Google used this signal to increase the visibility of content from trusted health-related sources.
Technical and Metadata Factors:
- Encoding Scores: These metrics assess the technical optimization of content for better user experience.
- SiteLinkOut: Measures how often the site links to other trustworthy or relevant websites, influencing the overall trust in the site.
Site and URL Level Predictions:
- Chard and Keto Scores: Additional internal models used to assess site quality and the effort put into content creation.
- Normalized Site Reliability (NSR): Reflects the reliability or authority of a site over time.
While it’s not possible to directly calculate TOFU through Google Search Console or Google Analytics, website owners can indirectly evaluate factors that may influence TOFU by analyzing quality and trust signals of a new site through available metrics in these tools.

Key Indicators for TOFU Analysis via GSC and GA
Google Search Console (GSC) Metrics:
a) Impressions: High impressions with low CTR may indicate insufficient trust from Google, potentially suggesting a low TOFU score.
b) Click-Through Rate (CTR): A low CTR can indicate a lack of user and search engine trust in the new site. If a site receives impressions but few clicks, it may signify low content trust.
c) Indexing Errors: Issues with indexation (e.g., robots.txt errors, blocking important pages, 404 errors) can affect the overall perception of the site as quality and reliable. More errors may lead to a lower TOFU score.
d) Core Web Vitals: Metrics such as Largest Contentful Paint (LCP), First Input Delay (FID), and Cumulative Layout Shift (CLS) provide insights into the page’s technical quality, which can be an important factor in assessing its trustworthiness.
e) Security (HTTPS): The presence of HTTPS is a critical trust signal for Google. Sites without secure connections may significantly lower their TOFU scores.
f) External Links (Backlinks): If GSC records links from other authoritative sites, it can increase the trust level of the new resource. A strong backlink profile from authoritative sources is a positive signal for TOFU.
g) Mobile-Friendliness: Google pays attention to mobile optimization of sites. Poor mobile adaptation can negatively impact site perception, lowering TOFU.
Google Analytics (GA) Metrics:
a) Bounce Rate: A high bounce rate (low engagement) may indicate that the content doesn’t meet user expectations. This signals to Google that users don’t find the site useful, potentially leading to decreased trust (low TOFU).
b) Time on Page: Low time spent on a page may indicate that users don’t find the content useful or high-quality, which can also lower the site’s trust level.
c) New Users: If the site attracts new users, it’s a positive signal for Google. However, it’s important to monitor the quality of the attracted audience. High traffic with low-quality interactions (e.g., high bounce rate) will negatively affect TOFU.
d) Traffic Source: It’s important to track where users are coming from. Organic search is an important source for TOFU. If a site receives traffic through questionable sources, it may raise suspicion with Google.
e) Content Interaction: User engagement in the form of multiple page views per visit or use of interactive elements (video, forms) can signal to Google about the site’s usefulness.

Algorithms Supporting TOFU
TOFU is supported by several algorithms and models for ranking:
- SpamBrain: This system helps detect spam-like content and is crucial for assessing whether a new site exhibits signs of spam.
- Helpful Content System: TOFU may interact with systems like the Helpful Content System, which evaluates whether content is created for users rather than search engines.
- Normalized Site Reliability (NSR): TOFU scores are part of the broader NSR model, which incorporates various signals such as link analysis, content relevance, and quality assessments.
Importance of TOFU:
TOFU is a key metric for new sites that haven’t yet established a reputation. It works by evaluating numerous quality signals related to content, technical structure, and site authority. This ensures that new content is ranked appropriately without relying solely on past interaction data.
In conclusion, Trust on First Use plays a vital role in Google’s algorithm, particularly for emerging websites and content. By leveraging a diverse set of quality indicators, TOFU enables Google to make informed decisions about the trustworthiness and relevance of new online entities, thus maintaining the integrity and usefulness of search results for users.
