How Authoritative Is Your Domain to AI?
Check your rank in the web graph that trains ChatGPT, Claude, Gemini, and Perplexity.
Why Common Crawl authority feeds AI answers
Common Crawl is the open, petabyte-scale web archive that underpins much of the data used to train large language models. Its web graph ranks domains by Harmonic Centrality and PageRank — measures of how many authoritative sites link to yours. This tool looks a domain up in that graph and returns its rank, so you can gauge how visible your site is in the corpus AI systems learn from.
Domains with high harmonic centrality — established publishers, reference sites, and category authorities — are over-represented in training data and more likely to be recalled when an assistant answers. A strong Common Crawl rank signals durable, link-earned authority, the same signal that separates a citation-worthy source from one AI overlooks.
Key takeaways
- Common Crawl is a primary training source for LLMs; rank in its web graph correlates with how often a domain surfaces in AI answers.
- Harmonic Centrality and PageRank measure link-earned authority, not on-page SEO — they reward being cited by other authoritative sites.
- High-authority domains are over-represented in training corpora, giving them a recall advantage in generated answers.
- Rank complements an AI Placement Value Score: authority in the graph plus AI accessibility is what makes a domain worth a placement.
How It Works
From a domain to an AI authority signal in seconds.
Enter a domain
Type any website. We normalize it and look it up in the Common Crawl web graph.
Find it in the graph
We return its Harmonic Centrality rank and PageRank from the top 10 million domains.
Rank its authority
We place the rank into a named authority tier, from Elite down to Emerging.
Score its AI value
We add a full AI Placement Value Score so you can act on it.
Why Common Crawl Rank Matters
The web graph AI learned from shapes who it trusts.
It feeds AI training data
Common Crawl is one of the largest sources of AI training data. It crawls high-centrality domains most often, so authoritative sites show up more in what models learn. That gives them a head start in AI answers.
It changes earned media value
A placement is only as valuable as the authority of the site it lives on. Coverage on a deeply-connected domain moves the needle for AI far more than the same story on an isolated site.
Turn authority data into a strategy
Create a free Spyglasses account to check any domain and use this data to guide your earned media and backlink strategy.
Frequently Asked Questions
What does this tool check?
It looks up a domain in Common Crawl's web graph and reports its Harmonic Centrality rank, its PageRank, and where it sits in the overall graph. It also shows an authority grade from A to F and a full AI Placement Value Score.
What is Harmonic Centrality?
Harmonic Centrality measures how central a domain is in the web's link graph, based on how easily it can be reached from every other site through short link paths. A high score means many well-connected sites are only a few links away from you. It is harder to game than raw link counts, so it is a strong signal of real authority.
Why does Common Crawl rank matter for AI visibility?
Common Crawl is one of the largest sources of training data for large language models. It uses Harmonic Centrality to decide which sites to crawl most, so high-centrality domains appear more often in the data AI models learn from. That gives them a baseline familiarity and authority in AI answers.
Why do you only cover the top 10 million domains?
Common Crawl's full web graph contains hundreds of millions of domains. We load the top 10 million by Harmonic Centrality, which covers the sites with meaningful authority. If a domain is not in the top 10 million, we report it as unranked, which still tells you there is room to build its standing.
How is the authority grade calculated?
The grade is based on a domain's Harmonic Centrality rank. Grade A is the top 1,000 domains, B is the top 10,000, C is the top 100,000, D is the top 1,000,000, and E covers the rest of the tracked top 10,000,000. Domains outside the tracked set receive an F. The buckets are log-scale, so each grade is roughly a tenfold difference in centrality.
How can I improve my domain's rank?
Earn links and brand mentions from sites that are themselves deeply embedded in the web's core, such as major publishers and institutions. Link topology beats link volume: one link from a highly central site can move your Harmonic Centrality more than dozens from isolated pages. Keeping an accurate Wikidata entity and Wikipedia presence, and running earned media that produces authoritative coverage, all help over time.
How does this relate to the AI Placement Value Score?
The AI Placement Value Score combines a domain's organic authority (which includes its PageRank standing from this same Common Crawl data), how accessible it is to AI crawlers, and how much influence it carries in AI training data. Your Common Crawl rank is one of the core inputs, so a strong rank tends to lift the placement value of coverage earned on that domain.
Is this data live?
We refresh the dataset each time Common Crawl publishes a new web graph release. The results page shows which release is loaded, how many domains are tracked, and the date it was last updated, so you always know how current the numbers are.
Authority is half the story; whether AI can read you is the other half.
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