Where our data comes from

You should be able to check our work. Here is exactly what powers every number on this site.

The source

All link data comes from Common Crawl, a non-profit that has crawled the open web since 2008 and publishes the results freely. We use their domain-level hyperlink graph, release cc-main-2026-may-jun-jul, plus the previous release for change detection.

• 117,963,409 domains
• 2.77 billion domain-to-domain links in the current release
• 7.11 billion across the two releases we hold

How authority is computed

Common Crawl publishes harmonic centrality for every domain — a measure of how close a node sits to every other node in the graph. It is an established metric in network science, not something we invented.

We convert its rank to a 0–100 score on a logarithmic curve: score = 100 × (1 − ln(rank) / ln(N)), where N is the number of ranked domains. The log curve matters because the gap between rank 10 and rank 100 is enormous, while the gap between 1,000,000 and 1,000,090 is noise.

What we deliberately don't claim

• This is not Moz DA or Ahrefs DR. Those are proprietary scores on proprietary crawls. Ours will correlate, but it will not match.
• It is domain-level. One referring domain counts once, however many pages it links from.
• It is not real time. Data refreshes when Common Crawl publishes — every few months, not continuously.
• Coverage is broad, not complete. Common Crawl samples the web widely; it does not fetch every page of every site.

Why we spell this out

Most SEO metrics are black boxes, which lets vendors imply more precision than they have. Our source is public and our formula is one line, so you can reproduce any number here yourself. We would rather be checkable than impressive.