How Moz calculates DA and PA
Moz crawls the web, counts links between sites and trains a machine-learning model to predict rankings. The strongest inputs are the number of unique linking root domains and the authority of those linking sites. The scale is logarithmic: moving from 20 to 30 is much easier than from 70 to 80.
What is a good Domain Authority?
| DA | Typical site |
|---|---|
| 1–20 | New sites, small blogs and local businesses |
| 20–40 | Established niche sites |
| 40–60 | Strong brands and popular publications |
| 60+ | Major media, universities, government and global platforms |
DA is relative: compare yourself with the sites ranking for your keywords, not with Wikipedia.
DA is not a Google metric
Google does not use Moz DA. It is a third-party estimate that correlates with rankings. Use it to compare competitors, vet link prospects and track your own link growth over time — never as a goal in itself.
Spam Score
Spam Score is the percentage of sites with similar features that Moz found to be penalised or banned. 1–30 % is low, 31–60 % medium, 61 %+ high. A high score is a warning to investigate a site before seeking a link from it — not proof of spam.
How to raise your authority
- Publish genuinely useful resources people want to cite (data, tools, guides).
- Earn links through digital PR, partnerships and guest expertise — not paid link schemes.
- Fix broken backlinks by redirecting old URLs (see the Redirect Checker).
- Strengthen internal linking so authority flows to important pages.
Usage limit
This tool uses the Moz API. To keep it free, each visitor can check a limited number of new domains per month; re-checking a domain you already checked is free. See the full link profile with the Backlink Checker.
Frequently asked questions
What is a good DA score?
It depends on your niche. Compare your DA with the sites that rank for your target keywords; beating them matters more than any absolute number.
Does Google use Domain Authority?
No. DA is a Moz metric that estimates ranking potential. Google uses its own signals.
How often does DA update?
Moz updates its link index continuously and recalculates DA regularly. Changes usually follow new links being discovered or lost.
What is the difference between DA and PA?
DA scores the whole domain; PA scores a single page. A strong page on a weak domain can still have a high PA.
Why is my DA low even though I have backlinks?
DA depends on the number and quality of unique linking domains. Many links from a few sites, or links from low-quality sites, add little.