Keyword difficulty (KD) is a metric used by SEO tools to estimate how hard it would be to rank on the first page of Google for a specific keyword. It is typically scored from 0 to 100, where higher numbers mean more competition. Understanding KD is essential for choosing keywords that match your website's current authority.
How Keyword Difficulty Is Calculated
Different tools calculate KD differently, but they all look at roughly the same signals from the pages currently ranking on page 1:
- Backlink profiles: How many other websites link to the top-ranking pages. More backlinks generally means harder competition.
- Domain authority: The overall strength of the domains ranking on page 1. If the top 10 is filled with BBC, Wikipedia, and government sites, the keyword is very hard.
- Content quality: Some tools factor in content depth and relevance, though this is harder to quantify algorithmically.
- SERP features: If Google shows featured snippets, knowledge panels, or "People also ask" boxes, they push organic results further down the page.
The most influential factor is almost always backlinks. A keyword where the top-ranking pages each have hundreds of referring domains will have a much higher KD than one where the top pages have fewer than 10.
What the Scores Mean
While exact scales vary by tool, here is a general guide:
- KD 0-14 (Easy): Low competition. A new website with decent content can rank within a few months. These often have lower search volumes but are ideal starting points.
- KD 15-29 (Low): Achievable with good on-page SEO and a handful of quality backlinks. Most local business keywords fall in this range.
- KD 30-49 (Medium): You will need solid content, proper technical SEO, and 10-30 referring domains to compete. Expect 3-6 months of work.
- KD 50-69 (Hard): Established sites with strong backlink profiles dominate. Unless your site already has authority, these keywords require significant long-term investment.
- KD 70-100 (Very Hard): Dominated by major brands and high-authority sites. Small businesses should generally avoid targeting these unless the keyword is extremely relevant to their niche.
How to Choose Keywords You Can Rank For
The biggest mistake we see is businesses targeting high-volume, high-difficulty keywords and ignoring easier ones. A keyword with 200 monthly searches and KD 8 will drive more traffic than a keyword with 10,000 monthly searches and KD 75 — because you will actually reach page 1 for it.
Here is a practical process for keyword selection:
- Start with your services and location. "Plumber Truro" is much easier than "plumber" and far more relevant to your business.
- Check the KD for each keyword. Use our Keyword Difficulty checker to see the score, volume, and who currently ranks.
- Look at who is on page 1. If you see local businesses similar to yours ranking, that is a good sign. If it is all national brands, move on.
- Prioritise KD under 30. Target the easiest keywords first, build authority, then work your way up to harder ones.
- Consider search intent. A keyword like "SEO tips" attracts people looking for free advice. "SEO agency Cornwall" attracts people ready to buy. Lower volume with buying intent often converts better.
Why KD Scores Are Not Perfect
Keyword difficulty is an estimate, not a guarantee. There are situations where a high-KD keyword is actually quite accessible:
- The top results are outdated and have not been refreshed in years
- No one has written content specifically targeting the keyword — they rank incidentally
- The search intent has shifted and existing content no longer matches what searchers want
- A featured snippet exists that you could capture with well-structured content
Conversely, a low-KD keyword can be harder than expected if Google strongly favours a particular type of result (e.g., only showing e-commerce pages when you have a blog post).
For a deeper look at on-page SEO techniques that help you compete for your target keywords, read our guide on how to improve your Google ranking. If you encounter unfamiliar terminology along the way, our SEO glossary explains every term in plain English.