A content gap is a topic your competitors cover that you don’t. Not a single keyword - an entire subject area where your site has nothing and theirs has a page pulling traffic. Finding these gaps is the fastest way to build a content plan that isn’t based on guesswork, because every gap you identify comes with built-in proof of demand.
This guide walks through how to actually run a content gap analysis - the specific steps, the tools, and the filters that keep you from drowning in data.
Content gaps vs. keyword gaps
These terms get used interchangeably. They shouldn’t be.
A keyword gap is a list of specific search terms where a competitor ranks and you don’t. It’s granular - individual queries like “email drip campaign examples” or “project timeline template free.”
A content gap is broader. It’s about topics, angles, and coverage depth. You might rank for “email drip campaigns” but have nothing on drip campaign software comparisons, drip sequence templates, or automation workflows for drip campaigns. That’s a content gap - you’ve touched the subject but haven’t covered it with any depth.
Keyword gaps are a subset of content gaps. A keyword gap analysis tells you which terms to target. A content gap analysis tells you which entire subject areas are missing from your site.
Start with the content gap. It shapes your editorial strategy. Then drill into keyword gaps to plan individual pages.
Why content gaps matter more than keyword lists
Most SEO teams start with keyword research - brainstorming seed terms, expanding them, filtering by volume. That approach has a ceiling. You’re limited to what you already know about your market.
Content gap analysis starts from the other direction. You look at what’s working for competitors and ask: why don’t we have anything on this? The answers are usually revealing:
- Blind spots. Topics your team never thought to cover because nobody internally talks about them. Your competitors found them through their own research or stumbled into them.
- Avoided topics. Subjects someone decided weren’t worth covering two years ago. The search landscape changed and now they pull real volume.
- Depth gaps. You have a surface-level page. Your competitor has a 3,000-word guide with templates, examples, and a tool. Same topic, wildly different coverage.
Each of these is a different type of content gap, and each needs a different response.
How to run a content gap analysis in Ahrefs
Here’s the actual walkthrough. I’m using Ahrefs because its Content Gap tool is purpose-built for this, but I’ll cover SEMrush right after.
Step 1: Pick your competitors.
Open Ahrefs Site Explorer, enter your domain, and go to Content Gap (under Organic search in the left nav). Add three to five competitor domains in the “Show keywords that the below targets rank for” fields.
Pick competitors in your weight class. If you have a DR of 35, don’t compare yourself to HubSpot. Choose sites with similar authority that compete for the same audience. A good rule: sites that rank on page one for at least a few of your target keywords.
Step 2: Run the gap report.
Click “Show keywords.” Ahrefs will return every keyword where at least one competitor ranks in the top 100 and your site doesn’t rank at all.
This will be thousands of keywords. Don’t panic - most of them are noise.
Step 3: Filter aggressively.
- Set volume minimum to 100/mo. Below that, individual keywords rarely justify a standalone page.
- Set KD maximum to 35. You want gaps you can realistically fill, not terms that require a six-figure link building budget.
- Filter by “2 of” or “3 of” targets ranking. A keyword where multiple competitors rank is a stronger signal than one where a single outlier shows up.
Step 4: Look for topic clusters, not individual keywords.
This is where content gap analysis diverges from keyword gap analysis. Don’t scan the list keyword by keyword. Scan for themes.
Sort by volume and scroll through. You’ll notice groups: maybe your competitors all cover “content audit” variations and you have nothing. Or they have multiple pages on “editorial calendar” and you have one thin post. Those clusters of related keywords represent your content gaps.
Export the filtered list and group related terms. Twenty keywords about “content audit” variations are one content gap, not twenty separate opportunities.
Step 5: Assess what’s missing.
For each content gap, check whether you have:
- No page at all (true gap - you need to create something)
- A page that doesn’t rank (quality gap - you need to rewrite or expand)
- A page ranking on page two or three (optimization gap - you need to improve)
The response is different for each. Don’t create new pages when the real problem is that your existing page is thin.
How to run the same analysis in SEMrush
SEMrush calls this the Keyword Gap tool, but you can use it for content gap analysis with the right approach.
Step 1: Go to Keyword Gap under Competitive Research. Enter your domain and up to four competitors.
Step 2: Click “Compare.” SEMrush shows a Venn diagram and a keyword table. Switch the filter to “Missing” (keywords your competitors rank for and you don’t rank for at all) or “Weak” (keywords where you rank but significantly lower than competitors).
Step 3: Apply filters - same logic as above. Volume above 100, KD below 35. Use the “Advanced Filters” to exclude branded competitor terms.
Step 4: Export and cluster. SEMrush doesn’t group these into topics automatically, so you’ll need to do that yourself or use a keyword research tool that handles clustering.
The output is functionally the same as Ahrefs - a list of keywords representing topics where your site has gaps.
Turning gaps into a content plan
Finding gaps is the easy part. The hard part is deciding which ones to fill and in what order.
Score each content gap on three dimensions:
- Total opportunity. Sum the monthly volume of all keywords in the cluster. A gap with 15 keywords totaling 8,000 monthly searches is more valuable than a single keyword at 2,000.
- Difficulty. Average the KD across the cluster, weighted toward the primary term. Clusters with average KD under 25 go to the top of the list.
- Business relevance. Does this topic connect to your product? A gap in “free invoice templates” is worthless if you sell SEO software. Score each gap one to five on how closely it maps to your buyer’s journey.
Multiply opportunity by relevance, divide by difficulty, and you have a rough priority score. The gaps with the highest scores get written first.
Common mistakes that waste the analysis
Comparing against too many competitors. Five is the max. Beyond that, you get so many gap keywords that the signal drowns in noise. Three is usually the sweet spot.
Treating every gap keyword as a separate article. “Content gap analysis,” “content gap analysis SEO,” “how to do a content gap analysis,” and “content gap analysis tool” are not four articles. They’re one. Cluster before you write or you’ll cannibalize yourself.
Ignoring search intent. A gap keyword with informational intent needs a guide. One with commercial intent needs a comparison page or tool page. One with navigational intent for a competitor’s brand name needs to be skipped entirely. Check the SERP before you commit to writing.
Running the analysis once. Content gaps shift as competitors publish and Google re-evaluates rankings. Run a competitor keyword gap analysis quarterly. New gaps appear every time - competitors publish new content, your rankings fluctuate, and search demand evolves.
Skipping the depth check. Before creating a new page, search the gap keyword and look at what ranks. If positions one through five are all 3,000-word guides with custom graphics, your 800-word blog post won’t cut it. Match or exceed the depth of what’s already working.
What a finished content gap analysis looks like
After running this process, you should have:
- A list of 10 to 30 content gaps, each represented as a cluster of related keywords
- A priority score for each gap based on opportunity, difficulty, and relevance
- A clear action for each: create new page, rewrite existing page, or optimize existing page
- An estimated total addressable traffic if you fill the top gaps
That’s your content plan for the next quarter. No brainstorming required. Every topic on the list has proven demand and competitors you can study for structure, depth, and angle.
The sites that grow fastest in organic search aren’t the ones publishing the most content. They’re the ones publishing the right content - and content gap analysis is how you figure out what “right” means for your specific market.