Difficulty scores are the SEO market's answer to the patchwork state of all the data out there. All five tools we tested stood out because they do offer some version of a difficulty metric, or one holistic 1-100 score of how difficult it would be for your page to rank organically (without paying Google) on a particular keyword. Difficulty scores are inherently subjective, and each tool calculates it uniquely. In general, it incorporates PA, DA, and other factors, including search volume on the keyword, how heavily paid search ads are influencing the results, and how the strong the competition is in each spot on the current search results page.
It might be awkward, but please don't scroll past this. This Monday we humbly ask you to defend Wikipedia's independence. Our 2019 fundraiser is about to be over. 98% of our readers don't give; they look the other way. If you are an exceptional reader who already donated, we sincerely thank you. If all our readers donated just $2.75 today, Wikipedia could keep thriving for years. Most people donate for a simple reason—because Wikipedia is useful. If Wikipedia gave you $2.75 worth of knowledge this year, take a minute to secure its future with a gift to the Wikimedia Endowment. Show the volunteers who bring you reliable, neutral information that their work matters. Thank you.