Rankfill

Comparing Competitors to Find Your Content Blind Spots

You open Ahrefs or SEMrush, type in a competitor's domain, and stare at a list of 4,000 keywords they rank for. You export it. You open the spreadsheet. You scroll for a few minutes, highlight some rows, close the tab, and never do anything with it.

That's not a you problem — that's a process problem. Raw keyword lists from a competitor's domain aren't actionable on their own. What you actually need is the gap: the keywords they're capturing that your site isn't. And more than that, you need to understand what kind of content is closing that gap, so you're building the right thing, not just more of whatever you already have.

Here's how to do it properly.

Why "comparing competitors" often fails

Most people run a content gap analysis once, feel briefly inspired, and abandon it. The reasons are predictable:

Comparing a single competitor gives you a partial view. One site might dominate informational content. Another might own transactional terms. A third might rank heavily in your category but serve a slightly different audience. You need to look at several to find the patterns — and the patterns are what tell you where your site is genuinely underserved.

Step 1: Identify 3–5 real competitors (not just brand names you recognize)

Start with the competitors that matter in search, not necessarily the ones you think of in your market. A direct business competitor might have a weak website. Meanwhile, a media site or a SaaS tool in a tangential space might be ranking for every term your customers search before they reach you.

Use a tool like Ahrefs, SEMrush, or Moz to look up which domains share keyword overlap with your site. This surfaces search competitors you might not have on your radar. Analyzing a competitor website for SEO gaps starts with knowing who the actual search competitors are — that list is often different from your business competitive set.

Once you have 3–5 domains, you're ready to run the comparison.

Step 2: Run a content gap analysis across all of them

A content gap analysis shows you keywords that one or more competitors rank for that your site doesn't rank for at all — or ranks very poorly for (position 20+, essentially invisible).

In Ahrefs: go to Site Explorer → your domain → Content Gap → enter your competitors. Set the filter to show keywords where competitors rank in the top 10 but your site doesn't appear in the top 20. Export the results.

In SEMrush: use the Keyword Gap tool under Competitive Research. Input your domain and up to four competitors. Filter for keywords where competitors have positions and you don't.

The output will still be long. Your job now is to make it useful.

Step 3: Filter and cluster the gaps that actually matter

Don't try to work through 2,000 keywords one by one. Cluster them.

Look for groups of keywords that:

The keywords where 3 out of your 4 competitors rank and you don't — those are your real blind spots. They signal a content type or topic area that the market has decided matters, and your site hasn't covered it.

Also flag the gaps by intent:

Your gaps probably skew toward one of these categories. That tells you something about where your content strategy has a structural hole. Stealing the keywords your competitors rank for covers how to read intent signals from the SERP before you write.

Step 4: Look at what's actually ranking — not just the keyword

Before you write anything, go look at the pages that rank for the gaps you've identified. Open the top 3 results for 10 of your priority gap keywords.

Ask:

This step is where most people skip ahead. They see a keyword gap, write a page, and wonder why it doesn't rank. The page didn't match what the search result page is actually rewarding. The format matters. The depth matters. Whether the SERP wants one page or ten pages on related sub-topics matters.

If the gap shows 15 related keywords all pointing to the same general topic, that's probably one well-structured guide — not 15 separate thin pages.

Step 5: Build a prioritized content plan from the gaps

After clustering and reviewing SERPs, you should have a list of maybe 20–40 content opportunities, each tied to a real gap, a clear intent, and a rough format. Now prioritize by:

  1. Traffic potential: How much search volume does this cluster represent if you rank?
  2. Competition: Are the current ranking pages weak, thin, or outdated? Can you realistically compete?
  3. Business relevance: Will this traffic convert, build authority, or bring in the right audience?

Start with the intersection of high relevance and lower competition. Not everything with high volume is winnable. A keyword with 2,000 monthly searches dominated by Zapier, HubSpot, and Wikipedia is a different bet than a 400-search-per-month term where the current top results are generic blog posts from 2019.

For a more systematic approach to the full audit process, running a competition analysis on your website walks through how to size the opportunity before you commit resources to content.

What good output from this process looks like

When you've done this well, you end up with:

If you want to skip the manual export-and-cluster work, tools like Rankfill automate the competitor mapping and gap identification, returning a scored opportunity list and content plan you can act on directly.

The work of comparing competitors isn't about finding a magic keyword nobody else has found. It's about systematically identifying where your site is absent from conversations your customers are already having — and building the pages that earn a seat at that table.

FAQ

How many competitors should I compare against? Three to five is the practical range. One competitor gives you a skewed view. More than five and the data gets noisy and harder to action. Pick the domains that have the most keyword overlap with your site, not just the brands you consider rivals.

What's the difference between a content gap and a keyword gap? A keyword gap is when a competitor ranks for a term you don't. A content gap is when an entire topic area, intent type, or format is missing from your site. Keyword gaps point you to content gaps. You want to identify both.

Can I do this without paid tools? Partially. Google Search Console shows you what you do rank for. Google's "site:" operator and manual SERP browsing can show you roughly what competitors have indexed. But seeing what competitors rank for that you don't requires a crawler or keyword database — Ahrefs, SEMrush, or Moz are the standard options. Some have free tiers with limits. For deeper alternatives to expensive crawlers, there are options depending on your budget.

How often should I run a competitor comparison? Quarterly is enough for most sites. Markets don't shift that fast for established keywords. If you're in a rapidly changing space or a competitor is clearly making aggressive content moves, monthly checks make sense.

My competitor list is huge — how do I know which gaps to prioritize first? Cross-reference with multiple competitors. Any keyword where 2–3 of your competitors rank in the top 10 and you don't appear at all is a stronger signal than a single-competitor outlier. Also weight by intent — commercial and transactional gaps are usually worth more to your business than pure informational traffic, even at lower search volumes.

Do I need to match exactly what competitors have built? No. You need to match what the SERP is rewarding, which is informed by what competitors built but not identical to it. Look at the top results, understand what they accomplish for the searcher, and build something that does that at least as well. Often there's room to do it better.