SEO: How to Assess Keyword Difficulty

Identifying keywords for organic search rankings is easier now than a decade ago owing to advanced tools. A key factor in choosing a keyword is competition — the number and quality of sites already ranking for that term.

How can we know if a keyword is worth the effort?

I’ll address that question in this post.

Keyword Difficulty

All leading search-engine-optimization platforms offer a competition metric — a method of filtering keyword lists according to the difficulty of ranking on page 1 of Google.

Semrush suggests selecting keywords with difficulty below “14” as they are the easiest to rank for. Semrush uses multiple factors for that metric but most are likely related to backlinks — the number and authority of linking pages.

Moreover, Semrush includes “SERP-related qualities” for each keyword when calculating its difficulty. For example, a keyword that generates a featured snippet is relatively more difficult, per Semrush.

Semrush suggests keywords with a metric of 14 or below. Keywords that produce featured snippets are relatively more difficult. Click image to enlarge.

Ahrefs, another platform, recommends keywords with a difficulty below “10.”
To calculate, Ahrefs counts the number of referring domains linking to the top-ranking pages. No other calculation is needed, Ahrefs asserts.

On SE Ranking, keywords below a “9” difficulty are “Surefire” and “10-19” are “Effortless.” Hence both should be doable for newer sites. SE Ranking relies on its internal evaluation of ranking pages’ domain authority when calculating keyword difficulty.

On SE Ranking, keywords with a difficulty below “9” are “Surefire” and “10-19” are “Effortless.”

WebCEO has a more transparent approach for identifying keywords with higher demand and lower competition: the “Keyword Effectiveness Index.” It’s calculated by dividing the search volume (demand) by the number of Google search results (supply).

A query with a relatively higher KEI has a higher demand and lower supply and is thus easier to rank for.

I appreciate the openness in calculating KEI — no hidden formulas. But double-check KEI’s conclusions on other platforms nonetheless.

For example, take the query “best email client for windows 10”:

• Ahrefs: 58 (difficult)
• Semrush: 73 (difficult)
• SE Rankings: 48 (doable)
• WebCEO: 6.93 (difficult)

Or “mozilla thunderbird email”:

• Ahrefs: 54 (difficult)
• Semrush: 87 (difficult)
• SE Rankings: 46 (doable)
• WebCEO: 9.9 (difficult)

Google allintitle: Search

Finally, another tactic for assessing keyword competition is searching Google for [allintitle:keyword], as in allintitle:best email client for windows 10.

This will produce search results for all the pages with your query in the title. Likely these are competitors who are optimizing for your keyword. Comparing the number of results of various keywords provides an estimate of how many sites are optimizing for each.

For example, Google’s allintitle: search results:

• “best email client for windows 10”: 27 (doable)
• “mozilla thunderbird email”: 6,630 (difficult)

Searching Google for “allintitle:best email client for windows 10” produces 27 results. Click image to enlarge.

Optimize for Humans

There’s no universal formula for keyword difficulty. None of the four tools above consider internal links or on-page SEO — a critical weakness. Keyword difficulty metrics merely help estimate the time and effort to achieve a page 1 Google ranking. There’s no reason to avoid competitive terms.

Remember to create content for humans, not Google. A search query represents a need. Address it regardless of whether it would rank.