Keyword Research with Ahrefs and SEMrush: A Practical Guide
Keyword research is the foundation of SEO. Target the wrong keywords and your content gets zero traffic. Target the right ones and it ranks for years. Here is how to use Ahrefs and SEMrush to find keywords worth pursuing.
Why Keyword Research Matters
Every search query represents a real person with a real need. When you understand what people search for, you can create content that serves those needs and ranks for those queries.
Without keyword research, you are guessing. With it, you are making data-driven decisions about what content to create.
The Key Metrics
Before diving into tools, understand what the metrics mean:
Search Volume (SV): How many people search for this keyword per month. Higher is better, but high-volume keywords are usually more competitive.
Keyword Difficulty (KD): How hard it is to rank for this keyword. Ahrefs and SEMrush calculate this differently, but generally:
- 0-10: Very easy (new sites can rank)
- 11-30: Moderate (possible with good content and some links)
- 31-50: Hard (needs significant content quality and domain authority)
- 51-70: Very hard (needs strong domain authority and many backlinks)
- 70+: Extremely hard (major established sites only)
Click-Through Rate (CTR): What percentage of searches result in clicks. Some searches get zero clicks (Google answers the question directly in search results). Look for keywords with high CTR.
Cost Per Click (CPC): How much advertisers pay per click. High CPC indicates commercial value. Keywords with $5+ CPC are in profitable niches.
Search Intent: What the searcher wants to do — learn, navigate, compare, or buy. Match your content format to the intent.
How to Use Ahrefs for Keyword Research
Ahrefs is the gold standard for keyword research and backlink analysis. Here is the workflow:
Step 1: Seed keyword brainstorm. Enter a broad topic related to your niche. For a freelance writing blog, seed keywords might be: "freelance writing," "content writing," "copywriting," "writing jobs."
Step 2: Use Keyword Explorer. Enter a seed keyword into Ahrefs Keyword Explorer. You will see:
- Search volume for the keyword
- Keyword difficulty score
- Related keyword ideas (thousands of them)
- SERP overview (who currently ranks)
Step 3: Filter for achievable keywords. Apply filters to narrow down:
- Volume: 100-5,000 (sweet spot for most sites)
- KD: Below 30 (for newer sites) or below 50 (for established sites)
- Exclude keywords you cannot target (unrelated to your niche)
Step 4: Analyze the SERP. For each promising keyword, look at the top 10 results:
- Domain Authority of ranking sites (can you compete?)
- Content depth of top results (can you create something better?)
- Content format (listicle, guide, tool, video?)
- Backlinks to top results (how many links do you need?)
If the top results are from sites like Wikipedia, Forbes, or major brands, the keyword is likely too competitive. If smaller, niche sites rank, you have a chance.
Step 5: Check keyword clusters. Ahrefs shows related keywords that often appear together. Group related keywords and create one comprehensive article that targets the cluster, not just a single keyword.
Example: "how to start freelance writing" might cluster with "freelance writing for beginners," "how to become a freelance writer," and "freelance writing tips." One article can rank for all of these.
How to Use SEMrush for Keyword Research
SEMrush offers similar functionality with some unique features:
Step 1: Keyword Magic Tool. Enter a seed keyword and SEMrush generates thousands of keyword ideas organized by topic clusters. Filter by volume, difficulty, intent, and CPC.
Step 2: Keyword Intent Filter. SEMrush categorizes keywords by intent:
- Informational: The searcher wants to learn ("what is email marketing")
- Navigational: The searcher wants a specific site ("Mailchimp login")
- Commercial: The searcher is comparing options ("best email marketing tool")
- Transactional: The searcher wants to buy ("Mailchimp pricing")
Target commercial and transactional keywords for affiliate and product content. Target informational keywords for traffic and authority building.
Step 3: Keyword Gap Analysis. Enter your domain and 3-5 competitor domains. SEMrush shows keywords your competitors rank for that you do not. This reveals content gaps you can fill.
Step 4: Position Tracking. Once you start publishing, track your rankings for target keywords over time. SEMrush monitors your positions and sends alerts when rankings change.
The Keyword Research Workflow
Here is the practical workflow for every new article:
1. Identify a topic idea. Based on your niche expertise, audience questions, or content gaps.
2. Find the primary keyword. Search the topic in Ahrefs or SEMrush. Identify the keyword with the best balance of search volume and achievable difficulty.
3. Find secondary keywords. Identify 5-15 related keywords that your article can also rank for. These should be variations, related questions, and LSI terms.
4. Analyze the competition. Look at the top 5 results. Can you create something better, more comprehensive, more current, or more useful? If not, choose a different keyword.
5. Determine search intent. What format do the top results use? Match it. If everyone ranks with a listicle, write a listicle. If they rank with a comprehensive guide, write a comprehensive guide.
6. Create the content. Write the best article on the topic. Include the primary keyword in the title, H1, first paragraph, and naturally throughout the content. Use secondary keywords in headings and body text.
Finding Low-Competition Keywords
Low-competition keywords are gold for newer sites. Here is how to find them:
1. Long-tail keywords. Keywords with 4+ words are less competitive. "Email marketing" (KD: 90) vs. "email marketing for small business Shopify stores" (KD: 15). The long-tail version gets less traffic but is achievable.
2. Question keywords. Keywords phrased as questions ("how to," "what is," "why does") often have lower competition. Use AnswerThePublic or the "People Also Ask" section in Google results to find them.
3. Local keywords. Keywords with geographic modifiers ("freelance writing jobs in Berlin") have lower competition and clear intent.
4. Fresh trends. New topics, tools, or trends have less established competition. Be among the first to publish comprehensive content on emerging topics.
5. Keyword gaps in established niches. In any niche, there are topics competitors have not covered. Use keyword gap analysis to find them.
Free Alternatives
If Ahrefs ($99+/month) and SEMrush ($120+/month) are too expensive:
Google Keyword Planner (free): Basic search volume data. Less detailed than paid tools but useful for volume estimates.
Ubersuggest (free tier, $29/month): Neil Patel's keyword tool. More limited but affordable.
Google Search (free): Search your topic and study the "People Also Ask" section and related searches at the bottom of the page. These are real searches Google shows you for free.
AnswerThePublic (free tier): Generates question-based keyword ideas from your seed keyword.
Start with free tools. As your site grows and generates income, invest in Ahrefs or SEMrush for professional-level research.
The Bottom Line
Keyword research is not a one-time activity. It is an ongoing process that informs your entire content strategy:
- Research before you write (ensure demand exists)
- Choose achievable keywords (do not waste effort on impossible targets)
- Match search intent (give searchers what they want)
- Track results (monitor rankings and refine your strategy)
- Repeat (keyword research never stops)
Every successful content website is built on keyword research. It is the difference between publishing into a void and publishing content that gets found, read, and monetized.