Keyword Difficulty Tools
Understanding organic search difficulty or keyword difficulty is really important for SEO. It helps you determine which keywords or keyphrases are worth your effort to go after, and which to avoid due to heavy competition in the top organic search results.
Several SEO software tools and platforms provide metrics for evaluating SEO difficulty. I introduce some of today’s best options below, along with some helpful videos that cover the topic.
Read on to learn much more and find an SEO keyword difficulty tool that may work best for you.
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Last Updated: Jan 13, 2021
What is Search Difficulty in SEO?
Determining Your SEO Ranking Potential
SEO search difficulty, also commonly referred to as keyword difficulty, is a numeric measure of how difficult it may be to rank on the first page of a search engine results page (SERP), based on the strength of competition already ranking for that search query.
The target search engine is usually Google, set for a specific region and index (desktop or mobile).
Search difficulty is also commonly called keyword difficulty, ranking difficulty, SEO difficulty, or SEO competitiveness.
- KD = Keyword Difficulty
- SD = Search Difficulty or SEO Difficulty
- RD = Ranking Difficulty
You’ll find that different SEO tools use one or more of these terms. They all refer to the difficulty score for ranking high in organic search results.
The actual search difficulty score is a number from 0 to 100, as explained further below.
Multiple Terms for SEO Keywords
Let’s spend just a minute on some basic SEO terminology before diving in too much further.
A target keyword may be a single word, but much more typically is multiple words in length. This makes it a keyphrase or key phrase. In Google Search Console, an actual typed or spoken user query is known as a search query.
So, there are multiple ways to say it, but the simple term ‘keyword’ is generally used to cover all of these terms when discussing keyword research and keyword difficulty in SEO.
I just wanted to be clear about that. Let’s keep moving…
Emphasis on Backlinks and Referring Domain Authority
Essentially all SEO tools that include keyword difficulty scores use the number of backlinks coming into the top SERP results to assess search difficulty.
This is usually the primary, and sometimes only, metric used in calculating a KD score for a specific search query.
Some SEO software vendors also look at the strength of the referring domains. They use Moz Page Authority and Domain Authority (PA/DA) or similar strength scores to give more or less weight to the incoming backlinks.
Some tools also include other factors, such as the raw number of search results with the full keyphrase in the Title tags and/or page URLs.
Each vendor weights these inputs differently, resulting in a proprietary KD scoring method for each tool.
In short, there is no single, industry standard formula for calculating keyword difficulty.
SEO Difficulty Scoring Ranges
All the software tools I’ve seen use a range of 1-100 for measuring keyword difficulty. Higher numbers indicate higher difficulty. Some tools also color-code the results. For example, green for easy KDs, yellow/orange for medium, and red for higher KDs.
They further break the 1-100 total range into sub-ranges that work something like the two examples below. (Mangools even goes to 6 difficulty ranges for KD scoring.)
- Low Difficulty: 0 – 33
- Medium Difficulty: 34 – 66
- High Difficulty: 67 – 100
- Low or Easy: 0 – 20
- Medium: 21 – 40
- Hard: 41 – 60
- Extremely Hard: 61 – 100
For new websites or blogs, and those with low to medium domain authority and weaker backlink profiles, the SEO vendors recommend sticking with keywords that fall into the lower difficulty ranges.
They also advise that sorting potential keyword targets strictly on KD scores (and the estimated monthly search volumes) is only a starting point.
You must also manually inspect the page 1 SERP results to get a better sense of the kinds of content the search engine is showing for that search query, and decide if you can develop stronger content to beat any of the top-ranking results over time.
SEO Search Difficulty vs. PPC Keyword Difficulty
Also, keep in mind that organic search difficulty is not the same as the PPC competition score.
SEO tools will show you both scores for the same keyword. Just keep them straight and remember that for organic ranking potential, you want to pay attention to the KD, SD, RD, or similar numeric score for organic keyword ranking difficulty.
Top SEO Tools with Organic Keyword Difficulty
There are many SEO tools that provide difficulty metrics for keywords. All of the complete SEO suites provide this information, since it’s so essential to the overall SEO keyword research process.
Here are several of the top tools, including how they cover the topic of keyword difficulty for organic search rankings. I’ve embedded several helpful explainer videos below as well.
Disclosure: I’m an affiliate for some of the tools mentioned in this post. I may earn referral fees from purchases made via links in this article, at no additional cost to buyers.
SEMrush is a powerful digital marketing platform for SEM and SEO, plus content and social media marketing.
As an all-in-one SEO tool, SEMrush also includes tools and metrics for assessing keyword difficulty for organic search.
Checking Organic Search Difficulty with SEMrush
SEMrush uses the term Keyword Difficulty for this part of its SEO feature set.
The SEMrush Glossary provides their definition of keyword difficulty:
They also incorporate difficulty metrics for groups of keywords, as defined here:
Scoring Based on Competitive Domain Authority
SEMrush provides a difficulty score in the 0 to 100% range, with the following breakpoints:
- Above 80%: High Difficulty
- 60 – 80%: Medium Difficulty
- Below 60%: Low Difficulty
These scores are based largely on their internal assessment of the authority of pages or posts that appear near the top of search results, e.g., Google’s Page 1 SERP for a specific index and geographic region.
They also estimate how hard it would be for another website to outrank these existing SERP competitors.
See the first video below, Step 3 at about the 3-minute mark, for more on using keyword difficulty in SEMrush to find low-competition keywords.
The second video is also helpful on this topic, using the SEMrush Keyword Magic tool.
SEMrush and Keyword Difficulty
Using the SEMrush Keyword Magic Tool
The SEMrush Knowledge Base has more on keyword difficulty here.
If you like what you see in the Keyword Overview and want to explore all areas of SEMrush further, consider signing up for a free 7-day trial here.
You can also read all the latest keyword research news from SEMrush here.
Organic Keyword Difficulty vs. PPC Competitive Density
Also, note the distinction between Keyword Difficulty for organic SEO ranking purposes, and Competitive Density metrics for measuring PPC competition.
As mentioned above, these metrics serve different purposes, so just be clear about this when doing keyword research for SEO, vs. estimating PPC advertising competition.
Keyword Difficulty with a Total Backlinks Focus
Many SEO practitioners and digital marketers know about Ahrefs. It’s one of the premium cloud-based tool kits available for keyword research, backlink profile analysis, and other SEO tasks.
Ahrefs’ keyword difficulty is included within their Keywords Explorer interface, as shown below.
Counting Backlinks Only
Unlike some SEO vendors, the KD scores in Ahrefs are based solely on the raw number of backlinks coming into the top-ranking search results.
Ahrefs KD score = Weighted average of the numbers of referring domains pointing to the top 10 ranking web pages in the SERP for a specific keyword.
They do not try to augment the keyword difficulty calculation with other factors that might impact organic search competitiveness. KD in Ahrefs is purely based on the *quantity* of incoming links.
The first video below provides a quick primer on using the Ahrefs KD metric.
Ahrefs Keyword Difficulty - Brief Overview
The Ahrefs KD Score is Not Linear
An interesting aspect of Ahrefs is that they provide an estimate of the number of referring domains you might require to rank in the top 10 SERP positions for a given target keyphrase.
They note that this is not a linear scale or estimate. As the KD gets more challenging, the estimated number of backlinks or referring domains gets much higher, in a non-linear fashion.
Ahrefs Keyword Difficulty Ranges and Referring Domains Needed
- 0 – 10: Easy (< 10 referring domains needed to rank high)
- 11 – 30: Medium (11 – 36 referring domains needed)
- 31 – 70: Hard (37 – 200 domains needed)
- 71 – 100: Super Hard (200+ domains needed)
Ahrefs’ KD score does not take into account the domain authority of referring domains. In Ahrefs this is also known as Domain Rating.
They also don’t try to measure the ‘quality’ of the incoming links.
This Ahrefs blog post on keyword difficulty is also helpful.
How Reliable are Keyword Difficulty Scores?
See the video below for a great discussion about the reliability of keyword difficulty scoring.
We learn that KD can be a very helpful metric when doing smart keyword research and prioritization, but it’s far from a perfect stand-alone metric for guiding keyword targeting decisions.
In short, KD is one important consideration for SEO keyword planning, but you’ll want to look at the whole picture when targeting specific content topics and associated keywords and phrases.
Are Keyword Difficulty Scores Reliable?
Keyword Difficulty within a Full SEO Suite
SEO PowerSuite is the paid tool I use regularly for many SEO tasks, for my own websites as well as client sites.
They also use the term Keyword Difficulty, and include this measure inside the SEO PowerSuite Rank Tracker software app.
The video below provides a good introduction to using keyword difficulty within SEO PowerSuite. It shows an older user interface for Rank Tracker, with different SEO metrics visible for the KD score vs. what’s there currently.
However, the overall ideas here on keyword difficulty are essentially the same.
Keyword Difficulty in SEO PowerSuite
SEO PowerSuite Keyword Difficulty Calculation
Here’s an excellent guide to using SEO PowerSuite for keyword difficulty analysis.
Note the Keyword Difficulty column in the right side of this screenshot:
As usual with KD scoring, the range is 1-100.
SEO PowerSuite also uses color coding to indicate difficulty levels. For example, dark green is very easy, yellow/orange indicates medium to hard KD, and dark red indicates really high difficulty levels.
InLink Rank and Domain InLink Rank
SEO PowerSuite currently shows four main factors that go into their overall difficulty scores. These apply to each ranking result for any specific keyword in question.
These factors are:
- InLink Rank: A measure of page-level authority, based on backlinks to the page
- Domain InLink Rank: A measure of overall domain authority, based on backlinks to the entire domain
- Sites Linking to Page: The number of external websites linking to the page
- Sites Linking to Domain: The number of external sites linking to the entire domain
My Experience Using SEO PowerSuite’s Keyword Difficulty
Based on my own experience using SEO PowerSuite, I can say that there is pretty good general correlation between low-medium KD values and better content ranking positions.
In other words, I do find it easier to rank new content for keywords in the low to medium SEO difficulty range. Conversely, content with weak rankings tends to be for keywords that have high KD.
I also see that, with time and continued SEO work, my content starts to rank better for higher KD scores.
So, yes… the KD score in SEO PowerSuite is useful. Just don’t rely on it as an all-knowing and all-powerful metric for assessing your organic ranking potential.
Keyword Difficulty with PA and DA Analysis
Like SEMrush, Moz Pro is a complete, premium platform for SEO analysis and keyword planning.
Moz focuses this activity within their Keyword Explorer.
As explained in their page on the Moz Keyword Difficulty tool, they also use a proprietary approach to measuring KD.
The Moz KD score incorporates:
- Page Authority (PA)
- Domain Authority (DA)
- Projected Click-Through Rates (CTR)
- Presence of new content on high-DA sites
Moz also includes an intelligent, proprietary Volume Score and an Opportunity Score that adjusts for presence or absence of Google SERP features, such as images, videos, ads, answer boxes, etc., that take up SERP screen space and push down the organic results.
This extra information in the upper part of the SERP generally means lower CTR for the organic results further down, and is factored into the Moz Opportunity Score.
Also see this analysis by Moz of 6 major keyword difficulty tools.
For a decent 5-minute overview of the Moz Keyword Explorer and Keyword Difficulty factor, see the video below.
Using the Moz Keyword Explorer
Use KWFinder to Check SEO Difficulty
Like other SEO tools, Mangools has its own version of scoring SEO Difficulty, primarily within its popular KWFinder tool.
The video below provides a useful overview. It explains how you can find long-tail keywords with low KD, or SEO difficulty.
This point about targeting longer-tail keywords, meaning search queries that generally have more words in them, is common among all the major SEO tools providers.
These longer search phrases are typically associated with lower organic search difficulty.
Mangools KWFinder Demo Video
The Mangools Updated Keyword Difficulty (KD) Calculation
In September 2018, Mangools explained their updated KD scoring method.
Their blog post (linked above) describes the updated metric in detail.
Mangools’ updated KD scoring now incorporates a combination of Moz and Majestic scores. These are the familiar Moz PA and DA metrics, plus the Majestic Trust Flow and Citation Flow scores (TF and CF).
The result, according to Mangools, is a much more realistic and up-to-date view of keyword difficulty.
Note that the KWFinder KD score is meant to measure how difficult it currently is to get on the first page of Google’s organic results, not the number one position.
They also updated their KD scoring into six ranges, as shown below.
It’s great to see an SEO tools vendor paying such close attention to the accuracy and usefulness of their SEO search difficulty calculations.
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Comprehensive Keyword Difficulty Scoring
Serpstat goes beyond many of the other vendors when it comes to SEO difficulty scoring.
Simply put, they incorporate more factors than others, including examining Title tag and ranking URL structure as indicated in the bullet points below.
Serpstat’s KD score is based on the following data:
- Number of backlinks coming in to the top ranking pages
- Referring domains for top ranking pages
- Serpstat’s Page Rank and Trust Rank scores
- Number of domains with the exact match keyword in the title tag
- Number of pages with the entire keyword in the URL
- Number of high-level pages in the top of the SERP
This screenshot shows their KD scoring column within the keyword analysis report.
The KD ranges for Serpstat are:
- 0-20: Easy
- 21-40: Medium
- 41-60: Difficult
- 61-100: Very Difficult
See the video below for a good intro to the Serpstat KD feature.
Understanding Serpstat's Organic SEO Difficulty Score
They also offer methods and tips for analyzing SEO keywords for topic niches. The post includes more on their keyword difficulty analysis, as well as their API access features to build KD clusters based on keyword topics.
Many readers in the field of digital marketing are aware of Neil Patel and his new comprehensive SEO platform known as Ubersuggest.
I used an earlier version of Ubersuggest in this post about SEO keyword research for content planning.
Ubersuggest uses the term SEO Difficulty instead of Keyword Difficulty, but it’s the same concept.
In the video below, you’ll see references and sample Ubersuggest screen views with the SEO Difficulty (SD) and Paid Difficulty (PD) metrics in various areas and columns for potential keywords.
When using Ubersuggest, it’s best to focus your keyword targets on keyphrases with SEO difficulty scores of less than 40-50. The SD range is 1-100, which is similar to other tools.
It’s not totally clear what factors go into Ubersuggest’s SEO difficulty score, but I’m betting it’s highly dependent on the number of backlinks coming into the top 10 SERP results on Google.
This seems to be the common denominator for keyword difficulty across all SEO tools.
Ubersuggest Intro and Training Video
SpyFu is another comprehensive SEM tools platform that covers many aspects of SEO and PPC marketing.
SpyFu uses Ranking Difficulty as its metric for SEO keyword difficulty. You may also see the terms ‘keyword difficulty’ and ‘SEO difficulty’ used within their website content and blog posts.
Ranking Difficulty is a feature within their SEO Keywords analysis module.
SpyFu explains their approach to measuring and using keyword difficulty here.
Like other vendors, SpyFu uses a 1-100 range for ranking difficulty, with values closer to 100 of course indicating highest difficulty.
SpyFu’s RD (or KD) range breaks down like this:
- Under 30%: Low Difficulty
- 30% – 70%: Medium Difficulty
- Over 70%: High Difficulty
See this video for more about using SpyFu for organic keyword research and ranking difficulty analysis.
SpyFu Keyword Analysis & Ranking Difficulty
Different Approaches to Measuring SEO Search Difficulty
All of the SEO tools covered above are comprehensive platforms for performing a range of SEO and digital marketing tasks.
They all provide features for assessing organic search difficulty during the keyword research process.
And, they all do it a bit differently, as also described above.
In the end, you probably will not want to choose an SEO platform based only on its keyword difficulty features or perceived KD accuracy.
However, since organic KD scoring is often very important for SEO content and topic decision making, it’s a really good idea to know how your preferred SEO tool handles this function.
Comments and Feedback
What’s your experience using SEO platforms for keyword difficulty analysis?
How do you use it in your normal keyword research workflow?
What other SEO tools should I include in this post?
Feel free to add your thoughts below.
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