Domain authority
c40.org domain authority
c40.org has a domain authority score of 59 out of 100 (moderate), based on 3,751 referring domains and a web graph rank of 8,580 among 133 million domains.
All metrics for c40.org
| Authority score | 59 / 100 |
|---|---|
| Referring domains | 3,751 |
| Web graph rank (harmonic centrality) | #8,580 (top 0.01%) |
| PageRank position | #25,968 |
| Subdomains seen in the crawl | 11 |
| Majestic Million rank | #14,281 |
| Majestic referring subnets / IPs | 2,800 / 4,522 |
| Traffic rank | not in Chrome's top 1M |
| Position by authority in our top 20,000 | #9,579 |
Top referring domains of c40.org
These are the 10 best-connected websites that link to c40.org in the Common Crawl domain-level web graph (release cc-main-2026-jul-aug-sep, updated quarterly). c40.org has 3,751 referring domains in total; 2,360 of them are among the 5,000,000 best-connected domains of the graph, which are the ones we can list and rank here.
| # | Referring domain | Authority | Traffic rank |
|---|---|---|---|
| 1 | google.com | 98 | Top 1K (Chrome) |
| 2 | wikipedia.org | 91 | Top 1K (Chrome) |
| 3 | microsoft.com | 89 | Top 1K (Chrome) |
| 4 | amazon.com | 88 | Top 1K (Chrome) |
| 5 | europa.eu | 88 | Top 50K (Chrome) |
| 6 | cloudfront.net | 87 | Top 50K (Chrome) |
| 7 | amazonaws.com | 87 | Top 50K (Chrome) |
| 8 | blogspot.com | 86 | Top 50K (Chrome) |
| 9 | github.io | 84 | Top 50K (Chrome) |
| 10 | medium.com | 84 | Top 5K (Chrome) |
Domain-level data: each row is a whole domain that links to c40.org at least once somewhere on its site, not a single backlink or page, and no anchor text or link type is included. Common Crawl samples the public web, so a link can be missing and commercial backlink tools will show more.
Traffic rank of c40.org
c40.org is not in Chrome's global top 1M websites in August 2026, but is listed in 10 countries. Six-month trend: dropped out of the global top 1M. In the global top 1M in 7 of the last 12 months.
Top countries
| Country | Chrome rank in that country |
|---|---|
| Romania | Top 100K |
| Germany | Top 500K |
| India | Top 500K |
| United Kingdom | Top 500K |
| Kenya | Top 50K |
| Indonesia | Top 500K |
| Italy | Top 500K |
| Canada | Top 500K |
Last 12 months (global)
| 2025-09 | 2025-10 | 2025-11 | 2025-12 | 2026-01 | 2026-02 | 2026-03 | 2026-04 | 2026-05 | 2026-06 | 2026-07 | 2026-08 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| Top 1M | Top 1M | Top 1M | Top 1M | Top 1M | Top 1M | Top 1M | – | – | – | – | – |
Source: Chrome UX Report (Google, CC BY 4.0), the monthly popularity lists of origins by real Chrome page loads. A rank is a bucket, not an exact position: "Top 10K" means among the 10,000 most visited origins. It measures reach in Chrome, not visits, so it is not Similarweb traffic. Rank lists by country: Traffic rank by country.
How the authority score is calculated
The score is the average of two parts, each from 0 to 100:
- Rank part:
100 × (1 − log10(rank) / log10(N))^0.6, where rank is the domain's harmonic centrality position in the Common Crawl web graph (how close it is to every other domain through links) and N is the number of ranked domains (133,241,980). - Link part:
100 × log10(1 + referring domains) / 7, so 10 million referring domains = 100.
For this domain: rank part 67.2 (web graph rank 8,580 of 133,241,980), link part 51.1 (3,751 referring domains), average 59.1, rounded to 59.
It is consistent across all 120 million domains in the data, so it is good for ranking and filtering lists. It is not Moz Domain Authority or Ahrefs Domain Rating. Referring domains count other domains that link to this one, not individual backlinks; no list of linking pages is included.
Domains with a similar authority score
| # | Domain | Authority | Referring domains | Web graph rank | Traffic rank |
|---|---|---|---|---|---|
| 9,575 | bookbaby.com | 59 | 3,759 | 10,843 | Top 500K websites (Chrome) |
| 9,576 | ebony.com | 59 | 3,754 | 8,485 | Top 500K websites (Chrome) |
| 9,577 | nls.uk | 59 | 3,753 | 10,829 | Top 1M websites (Chrome) |
| 9,578 | h-net.org | 59 | 3,751 | 7,330 | Top 500K websites (Chrome) |
| 9,580 | xprize.org | 59 | 3,751 | 9,916 | Top 1M websites (Chrome) |
| 9,581 | mlq.ai | 59 | 3,747 | 10,378 | not in Chrome's top 1M |
| 9,582 | ird.fr | 59 | 3,747 | 11,379 | Top 1M websites (Chrome) |
| 9,583 | nsta.org | 59 | 3,746 | 9,530 | Top 1M websites (Chrome) |
Compare and browse
FAQ
- What is the domain authority of c40.org?
- c40.org has a domain authority score of 59 out of 100 (moderate), based on 3,751 referring domains and a web graph rank of 8,580 among 133 million domains. The score is our own open-data metric (0-100) and is not Moz Domain Authority or Ahrefs Domain Rating.
- How many backlinks does c40.org have?
- c40.org is linked to from 3,751 other domains in the Common Crawl web graph (release cc-main-2026-jul-aug-sep). This counts referring domains, not individual backlinks, and Common Crawl does not see the whole web, so commercial tools that crawl more will show larger numbers.
- How does c40.org rank among all websites?
- Its web graph rank (harmonic centrality) is 8,580 out of 133,241,980 ranked domains, which puts it in the top 0.01%. Its PageRank position is 25,968. Majestic Million ranks it #14,281.
- Is the c40.org authority score the same as Moz DA or Ahrefs DR?
- No. It is an independent score computed from open data (Common Crawl, Majestic Million, Chrome UX Report). It is consistent across all domains, so it works for comparing and filtering sites, but the numbers will not match the commercial tools.
- Which websites link to c40.org?
- The best-connected referring domains of c40.org in the Common Crawl web graph (release cc-main-2026-jul-aug-sep) are google.com, wikipedia.org, microsoft.com, amazon.com and europa.eu. This is a domain-level list from a quarterly crawl, so it names whole domains that link to c40.org, not individual backlinks, and it is not complete.
- What is the traffic rank of c40.org?
- c40.org is not in Chrome's global top 1M websites in August 2026 (Chrome UX Report).