About the DA PA Checker
Domain Authority and Page Authority are Moz's predictive scores, on a logarithmic 1–100 scale. They are not Google metrics, they are not used in ranking, and Google has said so repeatedly. They are a convenient shorthand for how strong a link profile looks compared with others.
This tool needs a Moz API key, which you add in the configuration file. Moz offers a free tier with a modest monthly quota; without a key the tool explains what is missing rather than inventing numbers.
Use the scores for comparison, never as a target. Moving from 20 to 30 is a different amount of work than moving from 60 to 70 because the scale is logarithmic, and a site with a lower score and a tightly relevant audience is often the better link to have.
Common questions
Is Domain Authority a Google ranking factor?
No. It's a third-party metric from Moz built to predict ranking potential on a logarithmic scale — Google has said repeatedly it does not use DA or PA in its own algorithm.
Why do I need an API key for this tool?
Domain and Page Authority are proprietary Moz metrics accessed through their API. Moz offers a free tier with a limited monthly quota, which is enough for occasional lookups.
Is moving from DA 20 to 30 the same effort as 60 to 70?
No — the scale is logarithmic, so gains get progressively harder at higher scores. Use the number to compare sites relatively, not as an absolute target.