Domain authority
nih.gov domain authority
nih.gov has a domain authority score of 85 out of 100 (very high), based on 639,890 referring domains and a web graph rank of 53 among 133 million domains; its traffic rank is Top 5K websites (Chrome).
All metrics for nih.gov
| Authority score | 85 / 100 |
|---|---|
| Referring domains | 639,890 |
| Web graph rank (harmonic centrality) | #53 (top 0.01%) |
| PageRank position | #143 |
| Subdomains seen in the crawl | 3,020 |
| Majestic Million rank | #49 |
| Majestic referring subnets / IPs | 104,039 / 270,907 |
| Traffic rank | Top 5K websites (Chrome) |
| Position by authority in our top 20,000 | #56 |
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 86.7 (web graph rank 53 of 133,241,980), link part 82.9 (639,890 referring domains), average 84.8, rounded to 85.
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 |
|---|---|---|---|---|---|
| 52 | forms.gle | 85 | 677,896 | 54 | Top 500K websites (Chrome) |
| 53 | tumblr.com | 85 | 672,937 | 57 | Top 5K websites (Chrome) |
| 54 | paypal.com | 85 | 665,554 | 56 | Top 1K websites (Chrome) |
| 55 | reddit.com | 85 | 665,222 | 48 | Top 1K websites (Chrome) |
| 57 | adobe.com | 85 | 586,154 | 42 | Top 1K websites (Chrome) |
| 58 | vk.com | 84 | 676,229 | 82 | Top 100K websites (Chrome) |
| 59 | unsplash.com | 84 | 551,027 | 66 | Top 10K websites (Chrome) |
| 60 | fbcdn.net | 84 | 515,288 | 68 | not in Chrome's top 1M |
AI crawler policy
We could not read the robots.txt of nih.gov on 2026-10-02, so its AI crawler rules are unknown. Does nih.gov block GPTBot? →
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FAQ
- What is the domain authority of nih.gov?
- nih.gov has a domain authority score of 85 out of 100 (very high), based on 639,890 referring domains and a web graph rank of 53 among 133 million domains; its traffic rank is Top 5K websites (Chrome). The score is our own open-data metric (0-100) and is not Moz Domain Authority or Ahrefs Domain Rating.
- How many backlinks does nih.gov have?
- nih.gov is linked to from 639,890 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 nih.gov rank among all websites?
- Its web graph rank (harmonic centrality) is 53 out of 133,241,980 ranked domains, which puts it in the top 0.01%. Its PageRank position is 143. Majestic Million ranks it #49.
- Is the nih.gov 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.