Keyword difficulty in SEO with Semrush KD insights

Keyword difficulty (KD) is an SEO metric that quantifies how challenging it is to rank for a specific keyword, typically scored from 0-100, with higher scores indicating greater competition. For marketing leaders, understanding this metric is crucial for prioritizing content efforts and allocating resources effectively.

What is keyword difficulty?

Keyword difficulty measures the estimated effort required to rank for a specific keyword by analyzing several key factors:

• Competitor authority: The domain strength of sites currently ranking
• Backlink profiles: Quality and quantity of links pointing to top-ranking pages
• Content quality: Relevance and depth of existing top-ranking content
• Search intent alignment: How well existing content matches user intent

This metric helps you avoid wasting resources on overly competitive keywords while identifying opportunities with higher ROI potential. For example, targeting long-tail keywords like “project management software with Gantt charts” (lower competition) often yields better results than broad terms like “project management tools.”

SEO experts often use keyword difficulty as a strategic filter to determine which keywords deserve immediate attention versus those requiring more substantial resources or a longer-term approach.

How Semrush calculates keyword difficulty

Semrush employs a proprietary Keyword Difficulty (KD) score ranging from 0–100 to evaluate competition. The higher the score, the more difficult it is to rank for that keyword organically.

Semrush’s algorithm prioritizes:

• Organic competition: Number and strength of ranking domains
• SERP analysis: Evaluates content quality and keyword usage in top results
• Backlink profiles: Quality and quantity of links to top-ranking pages
• Domain strength: Authority metrics of competing sites

Unlike some tools that focus solely on backlink metrics, Semrush integrates broader SERP signals for a more comprehensive difficulty assessment. Their algorithm examines the overall competitive landscape rather than relying on a single factor, which tends to provide a more realistic assessment of ranking potential.

While Semrush doesn’t publicly disclose their exact formula (like most SEO tools), their approach is known to emphasize the authority of competing domains and the quality of their backlink profiles as primary ranking factors.

Interpreting Semrush’s KD scores

Difficulty Range	Interpretation	Best for
0-30	Low competition	New sites or low-authority domains
31-60	Moderate competition	Mid-tier sites with some established authority
61-100	High competition	High-authority sites in competitive niches

When you see “KD%” or simply “KD” in Semrush, this refers to the keyword difficulty percentage. For example, a KD of 45% indicates moderate competition that might be suitable for websites with average domain authority.

A real-world perspective: A KD score of 15 might represent a keyword like “homemade kefir recipes” which would be relatively easy to rank for with quality content, while a score of 85 for “best credit cards” indicates extremely tough competition dominated by financial institutions and established review sites.

Keyword difficulty vs. keyword competition

These terms are often confused but represent different concepts:

• Keyword difficulty: Measures how hard it is to rank organically in unpaid search results
• Keyword competition: Typically refers to paid search competition (PPC) and the cost-per-click for advertising

While related, these metrics serve different purposes in your SEO and marketing strategy. A keyword might have high organic difficulty but low paid competition, or vice versa.

For example, industry-specific technical terms might have low KD scores (easy to rank organically) but high keyword competition due to their commercial value to businesses in that niche. Conversely, informational queries might have high KD scores but relatively low PPC competition.

Keyword difficulty vs. personal keyword difficulty

Semrush also offers a “Personal Keyword Difficulty” feature that contextualizes the standard KD score based on your specific domain’s strength. This personalized metric provides a more accurate assessment of how challenging a keyword will be for your particular website to rank for, rather than a general market assessment.

The difference is significant:

• Standard KD: General market difficulty regardless of who is trying to rank
• Personal KD: Customized difficulty based on your domain’s authority and current rankings

This personalization is particularly valuable for businesses with varying levels of established domain authority. For instance, if your site has strong topical authority in a specific niche, your Personal KD for related keywords might be lower than the standard KD, revealing opportunities that generic metrics might not identify.

Best practices for using keyword difficulty in your strategy

1. Target moderate difficulty keywords: Focus on keywords with KD scores of 30–50 for balanced competition and opportunity.

2. Leverage long-tail keywords: Phrases with more words often have lower difficulty and higher intent. Use a free keyword clustering tool to identify related long-tail opportunities.

3. Combine with search volume: Don’t just look at difficulty—balance it with search volume to ensure sufficient traffic potential. A keyword with KD 20 and 2,000 monthly searches might be more valuable than one with KD 15 and 100 searches.

4. Consider search intent: Ensure your content aligns with what users are actually searching for, regardless of difficulty score. Even low-difficulty keywords won’t convert if your content doesn’t satisfy user intent.

5. Audit existing content: Identify “breakout pages” (keywords your site ranks for without dedicated pages) to avoid cannibalization and improve rankings. These represent opportunities to formalize content that’s already gaining traction.

6. Analyze competitors: Conduct thorough competitor keyword research to identify gaps and opportunities in your niche. Look for keywords where competitors rank but you don’t—especially those with moderate difficulty.

7. Group related keywords: Use keyword clustering to organize keywords by topic and create comprehensive content that targets multiple related terms. This approach often yields better results than creating separate pages for similar keywords.

How to check keyword difficulty

To check keyword difficulty in Semrush:

1. Log into your Semrush account
2. Navigate to the Keyword Magic Tool or Keyword Overview
3. Enter your target keyword
4. Review the KD score displayed in the results
5. Use filters to segment keywords by difficulty ranges

For more sophisticated analysis, consider using specialized keyword clustering tools that can help you identify patterns and opportunities across difficulty ranges.

Advanced users often export Semrush data to spreadsheets for custom analysis, creating scoring models that combine KD with other metrics like search volume, CPC, and SERP features to identify the most promising opportunities.

Current trends in keyword difficulty analysis

Recent developments in keyword difficulty analysis include:

• Data-driven keyword selection: Using CRM and support data to uncover high-intent, low-competition niche keywords. Customer questions often reveal valuable keywords that standard research might miss.

• Intent-based analysis: Going beyond difficulty scores to incorporate user intent signals. Many SEO professionals now segment keywords by intent (informational, navigational, commercial, transactional) before evaluating difficulty.

• AI-driven tools: Leveraging machine learning for more accurate difficulty predictions and semantic keyword grouping. These tools can identify content gaps and suggest priority topics based on your site’s existing authority.

• Hang time strategy: Recognizing that organic traffic persists even after SEO efforts stop, with an average 12-month decay period. This insight affects ROI calculations for difficulty-based keyword targeting.

The most successful SEO strategies now consider keyword difficulty as just one dimension in a multi-faceted approach that also accounts for business relevance, conversion potential, and content feasibility.

TL;DR

Keyword difficulty is a crucial metric for prioritizing SEO efforts, with Semrush’s KD score (0-100) providing a reliable assessment of ranking challenge. While no difficulty metric is perfect, combining Semrush’s insights with search intent analysis and competitor research enables more strategic content planning. Focus on keywords with manageable difficulty scores (30-50) for optimal results, and use ContentGecko to develop data-driven content strategies that balance difficulty with traffic potential for maximum ROI.