Rankfill

Competitor Checker: Spot the Keywords You're Losing To

You check your analytics. Traffic is flat. You've published content, cleaned up technical issues, built a few links. And yet, somewhere out there, a competitor you barely think about is pulling in thousands of visitors a month for searches you should own.

You don't know which searches. You don't know which competitor. You just know the gap exists.

That's the exact problem a competitor checker is built to solve.

What a Competitor Checker Actually Does

The name sounds simple, but there's a lot crammed under the hood. A competitor checker cross-references what keywords your site ranks for against what your competitors rank for — and surfaces the delta. That delta is your opportunity list.

Done well, it answers four questions:

  1. Who are your real search competitors (which may not be who you think)?
  2. What keywords are they ranking for that you aren't?
  3. How much traffic are those keywords worth?
  4. Which ones are realistically winnable based on difficulty and your current domain strength?

Without those four answers, you're doing keyword research blind — picking topics based on guesswork rather than what's actually sending traffic to competing sites right now.

Your Real Competitors Are Not Always Your Business Competitors

This trips people up constantly. Your business competitor — the other SaaS tool in your category, the other plumber in your city — may not be your search competitor at all.

Your search competitor is whoever shows up in the results for the same queries you want to rank for. That might be a media site, a comparison page, a forum thread, or a tool you've never heard of. If they're capturing the clicks you want, they are your competitor in the only context that matters for SEO.

A good competitor checker identifies these by looking at keyword overlap, not brand category. You input your domain, it finds who shares the most keyword territory with you. Those are the sites you need to study.

For a deeper look at how to pull this off manually and with tools, how to analyze competitors and steal their keywords walks through the full process.

How to Run a Competitor Check: Step by Step

Step 1: Start With Your Own Keyword Footprint

Before you can see the gap, you need a clear picture of where you currently stand. Pull every keyword your site ranks for in positions 1–100. Most tools let you export this as a CSV. That list is your baseline.

Don't skip this step. People jump straight to spying on competitors without knowing their own footprint, which means they can't tell the difference between a gap and something they already rank for.

Step 2: Identify Your Top Search Competitors

Enter your domain into a competitor checker tool. It will return a list of domains ranked by keyword overlap — the sites that compete with you most directly in search results. You're looking at the top 5–10.

Look at the overlap percentage. A site sharing 40%+ of your keywords is a primary competitor. A site sharing 10% might still be worth analyzing if they're winning on high-value terms you want.

Step 3: Pull Their Keyword Lists

For each competitor, export their full organic keyword list. You want keyword, ranking position, estimated monthly search volume, and keyword difficulty if available. Some tools also give you the URL that ranks for each keyword, which tells you exactly what type of content they used to win that position.

Step 4: Find the Gap

This is the core move: subtract your keyword list from their keyword list. What remains are terms your competitor ranks for that you don't — your content gaps.

Most tools have a built-in "keyword gap" or "content gap" feature that automates this subtraction. You input your domain and one or more competitor domains, and it returns the difference. That's the list you work from.

If you're finding this step clunky with your current toolset, screaming frog alternatives for content gap analysis covers several options that handle gap identification more cleanly.

Step 5: Score and Prioritize

A raw gap list might have thousands of keywords. You can't write content for all of them at once, and you shouldn't try. Filter by:

What you're left with after filtering is a prioritized content plan, not a wish list.

The Metrics That Actually Matter in a Competitor Check

Not every number a competitor checker spits out deserves equal attention. Here's how to read what matters:

Keyword Overlap Score

This tells you how much keyword territory you share with a competitor. Higher overlap means they're a more direct threat — and a more useful benchmark. Low overlap can mean they're in an adjacent space or that your site is significantly under-indexed compared to theirs.

Traffic Potential vs. Search Volume

Search volume is what people search for. Traffic potential is what the top-ranking page actually earns — which is usually higher because a single page ranks for dozens of related keywords. Some tools show you traffic potential rather than just volume for the primary keyword. That number is more honest about the upside.

Position Distribution

Where does your competitor rank? If they're sitting in positions 1–3 for a keyword, they have a strong piece of content and real authority there. Displacing them is harder. If they're in positions 6–15, the door is cracked — a well-built piece could move above them.

Content Type at the Ranking URL

Look at what type of page ranks. Is it a long-form guide? A comparison page? A product listing? A Reddit thread? This tells you what format Google is rewarding for that query. Match the format, then try to execute it better.

Common Mistakes When Running a Competitor Check

Only Checking One Competitor

The best keyword opportunities often come from studying three to five competitors, not just one. Each competitor has slightly different keyword wins. Overlapping all of them gives you a richer gap list and shows you which gaps are consistent across your competitive set — those are usually the highest-value ones.

Ignoring Ranking Position

A competitor ranking 47th for a keyword isn't really ranking. Don't treat their position-40 keywords the same way you'd treat their position-3 keywords. Filter your gap analysis to their top 20 or top 30 positions to focus on terms where they're genuinely capturing traffic.

Acting on Volume Without Checking Intent

High search volume means nothing if the intent doesn't match your offer. "What is [your category]" might get 10,000 searches a month, but if you're a B2B SaaS selling to procurement teams, informational awareness content may not convert. Check whether each keyword segment fits your funnel before you build for it.

Skipping Your Own Underperforming Content

Competitor checkers show you what's missing. But you may also have existing pages ranking in positions 8–20 that, with some improvement, could jump to positions 1–5. A full competitive analysis includes both gap-filling and strengthening what you already have.

For a structured way to diagnose underperforming pages alongside gaps, how to analyze a competitor website for SEO gaps gets into the page-level detail.

Tools for Running a Competitor Check

Several tools do this well. Here's what they're actually like to use:

Ahrefs

The gold standard for depth. Enter your domain, go to "Competing Domains" to find your search competitors, then use the "Content Gap" tool to surface keywords they rank for that you don't. Data quality is excellent, and the filtering options are sophisticated. Expensive — plans start around $99/month.

Semrush

Similar capability to Ahrefs. The "Keyword Gap" tool is slightly more polished in its interface. If you already use Semrush for other SEO tasks, this is your natural path. Comparable pricing.

Moz Pro

Good for smaller sites or teams already using Moz. Less granular than Ahrefs or Semrush but accessible. The "True Competitor" feature identifies your search competitors automatically.

Ubersuggest

A lighter-weight, lower-cost option. Useful for basic competitor keyword analysis without the enterprise price tag. Data coverage is thinner than the big two, especially for lower-volume terms.

Similarweb

Better for traffic estimation and channel analysis than pure keyword-level competitor comparison. Useful as a supplement when you want to understand traffic sources broadly.

If you're weighing these against each other in more detail, competitor analysis for any website: tools and tactics covers the tradeoffs across the major options.

What to Do With Your Gap List

Finding the gap is the diagnostic. What comes next is the actual work.

Build a Content Calendar From the Gap

Take your filtered, prioritized keyword gap list and assign each keyword cluster to a content type (guide, landing page, comparison, FAQ, etc.) and a target publish date. A gap list without a publication plan just sits in a spreadsheet.

Cluster Keywords Before Writing

Rarely does one keyword live alone. Group related keywords together — they often share enough intent to be covered in a single piece. Building one thorough guide that ranks for 30 related keywords beats building 30 thin pages targeting one keyword each.

Match Your Content Depth to Your Competitor's

Pull the top-ranking piece for each target keyword and look at it honestly. Word count, section depth, media, examples, internal links. If their guide is 3,000 words with six original screenshots and you're planning 800 words, you're not going to outrank them. Match depth first, then differentiate.

Track New Content Performance

After publishing, monitor ranking progress over 60–90 days. Most new content doesn't rank immediately — Google needs time to process and test it. If a piece hasn't moved after 90 days, look at your internal linking, on-page optimization, and whether the piece genuinely addresses the query better than what's currently ranking.

Turning a One-Time Check Into an Ongoing System

Competitor checking isn't a once-a-quarter task. Competitors publish new content constantly. Google reshuffles rankings. New competitors emerge.

Set a recurring process:

This turns a diagnostic tool into an early warning system.

If you want to understand the full scope of what a structured competitive analysis looks like as a system — not just a one-time check — competition analysis for your website: close the gap fast lays out a repeatable process.

When to Do It Yourself vs. Getting Help

Running a competitor check yourself makes sense if you have tool access, someone who can interpret the data, and a content operation ready to execute. The tool does the data work. The strategic work — prioritizing, clustering, writing, publishing — is all on you.

Some site owners have the domain authority to compete but are too understaffed to move fast enough on the content side. In that case, services that handle gap identification and content production together close the loop faster. Rankfill, for example, maps your competitors, scores your keyword opportunities, and produces publish-ready content as part of the same workflow — which can cut the time between "finding the gap" and "content live on site" from months to days.

Whether you build the system yourself or hand it off, the underlying logic doesn't change: find what your competitors rank for, determine what you're missing, and build the content that fills it.

FAQ

What's the difference between a competitor checker and a keyword research tool?

Keyword research tools help you find keywords based on topic, volume, or seed terms. A competitor checker starts from what your competitors are already ranking for and works backward. The output is more targeted — you're building from proven demand rather than hypothetical interest.

How many competitors should I check?

At minimum, three. Five to seven gives you a richer picture. Focus on the ones with the highest keyword overlap with your domain — those are the sites capturing traffic you should be competing for.

My competitor has way more domain authority than me. Is there any point in checking their keywords?

Yes, but use their keyword list as a long-term roadmap, not a short-term target list. Filter for lower-difficulty keywords where their authority isn't the deciding factor. Also look at what they rank for in positions 6–15 — those are often beatable even with lower authority.

How often should I run a competitor check?

Monthly for a quick pulse on your top two to three competitors. Full analysis quarterly. Also run one any time a competitor launches a major new content initiative or you see a sudden change in your own rankings.

Can I do a competitor check without a paid tool?

Partially. Google Search Console shows your own keyword data. Manually searching queries in incognito mode shows who ranks where. But to get competitor keyword lists at scale, you need a tool with crawled index data — Ahrefs, Semrush, or similar. Free tiers exist but cap your data significantly.

What do I do if my competitors are ranking for terms that have nothing to do with my business?

Skip them. Keyword gaps only matter if the traffic is relevant to your offer. A competitor that dominates top-of-funnel awareness content in a broad category may have thousands of keywords you don't want — and shouldn't try to win.

What if two competitors rank for the same gap keyword?

That's a signal to prioritize it. If multiple competitors are capturing traffic from a keyword you don't have, it's not a fluke — it's a legitimate content need your site is missing. Move that keyword up your list.

Does fixing technical SEO help with competitor gaps, or is it purely a content problem?

Both matter, but for keyword gaps specifically, the fix is almost always content. Technical SEO gets your existing pages indexed and crawlable. Keyword gaps exist because the page doesn't exist yet, or the content isn't competitive enough. Fix technical issues first so that your new content actually gets indexed properly — then build.