Knowing what keyword gap analysis is and actually running one are two different things. This guide skips the theory and walks through the process itself, tool by tool, including a version that costs nothing if you’re not ready to pay for Semrush or Ahrefs yet.

New to the concept? Start with our companion guide, What Is Keyword Gap Analysis?, which covers the four types of keyword gaps and how to prioritize them before you run this process.

Before you start: grab our free keyword gap analysis spreadsheet. Make a copy, and you’ll have somewhere to paste your results as you go through the steps below, with priority scoring already built in.

What You Need Before You Start

A few things to have ready before opening any tool:

Your own domain, obviously
A list of 3 to 5 competitors, ideally search competitors rather than just brand competitors (more on this below)
A goal for the output. Are you looking for new blog topics, product page opportunities, or gaps in a specific service category? This shapes how you filter results later.

Picking the Right Competitors

This step gets skipped more often than it should. The competitors you’d name off the top of your head aren’t always the sites actually competing with you in search results.

A quick way to find real search competitors: search 5 to 10 of your core keywords and note which domains show up repeatedly on page one. Those are your organic competitors, whether or not you’d consider them direct business rivals.

Competing Google Search Result Highliights

Best Platforms for Keyword Gap Analysis

Tool	Best for	Free tier	Starting paid price
Semrush	Most comprehensive gap tool, good for competitive markets	Limited (1-2 searches/day, capped results)	Around $139.95/month
Ahrefs	Strong backlink + content data alongside keyword gaps	No free tier for this feature, 7-day trial for $7	Around $129/month
Ubersuggest	Budget-friendly alternative with a genuinely usable free tier	Yes, generous for small sites	Around $29/month
Google Keyword Planner	Free, good for volume data, not built for gap analysis specifically	Yes, fully free with a Google Ads account	Free
Moz Keyword Explorer	Decent middle ground, smaller keyword database than Semrush/Ahrefs	Limited free queries	Around $99/month

Semrush and Ahrefs are the two most capable tools for this specific task since they’re both built with a dedicated gap analysis feature. For a business just getting started or watching every dollar, Ubersuggest paired with Google Keyword Planner gets you most of the way there manually.

Step-by-Step: Keyword Gap Analysis in Semrush

Semrush’s Keyword Gap tool is purpose-built for this, and it’s the fastest way to get a sorted list.

Log into Semrush and navigate to Keyword Gap under the SEO toolkit.
Enter your domain in the first field, then add up to 4 competitor domains in the fields alongside it.
Set the search type to “Organic” (there’s also a paid search gap option if you’re running ads, but organic is the one for content strategy).
Review the Venn diagram at the top of the results, which shows keyword overlap at a glance before you get into the full table.
Switch between the filter tabs: “Missing,” “Weak,” “Untapped,” “Unique,” and “All” to move between gap types.
Apply filters for search volume (a minimum of 10 to 50 monthly searches is a reasonable starting cutoff for most small-to-mid sites) and keyword difficulty.
Export the filtered list to CSV using the export button in the top right of the results table.

How to do keyword analysis with Semrush — Semrush Keyword Gap Analysis Dashboard

A tip worth knowing: Semrush’s free tier limits how many gap analyses you can run per day and caps how much of the result table you can view. If you’re testing the tool before committing to a plan, plan your competitor comparisons carefully rather than burning the daily limit on exploratory searches.

Step-by-Step: Content Gap Analysis in Ahrefs

Ahrefs calls this feature “Content Gap,” and it lives inside their Site Explorer tool.

Open Site Explorer and enter your domain.
Click “Content Gap” in the left-hand sidebar under the Organic Search section.
Enter competitor domains in the “but the following targets don’t rank for” field. Ahrefs allows several at once here.
Set the ranking position filter. The default is usually top 10, but widening it to top 20 can surface additional opportunities competitors are just starting to rank for.
Review the results table, which shows each keyword, volume, keyword difficulty score, and the position each competitor holds for it.
Sort by volume or by “Traffic potential” to prioritize which gaps to look at first.
Export to CSV or send directly to Ahrefs’ keyword list feature if you want to keep building out the list over time.

How to do keyword analysis on Ahrefs — Ahrefs Content Gap Dashboard

Ahrefs doesn’t offer a genuinely free tier for this feature. Their 7-day trial for a nominal fee is usually the most cost-effective way to test it if you’re not ready for a full subscription.

Step-by-Step: Free Keyword Gap Analysis (No Paid Tools)

This method takes longer, but it works, and it’s a reasonable starting point for a business not ready to pay for Semrush or Ahrefs yet.

Set up a free Ubersuggest account and run a “Keywords by Competitors” or domain overview search for each competitor.
Export or manually record their top-ranking keywords, focused on page one to page two results (positions 1 to 20).
Run the same domain overview search for your own site and export your ranking keyword list.
Build a comparison spreadsheet with columns for keyword, search volume, your position (if any), and each competitor’s position.
Use Google Keyword Planner to fill in volume data for any keywords Ubersuggest didn’t have solid numbers for. Keyword Planner requires a free Google Ads account, but you don’t need an active campaign to use the tool.
Sort the spreadsheet by keywords where a competitor ranks and your column is blank. That’s your missing-keyword list.
Filter for relevance manually, since free tools tend to have less accurate intent and relevance filtering than paid alternatives.

How to do keyword analysis on spreadsheets — Spreadsheet of a Keyword Analysis

This method is manual, but the underlying logic is identical to what the paid tools automate. The tradeoff is time spent building the spreadsheet versus money spent on software.

Adjustments for a Brand-New Website

A site with no ranking history needs a slightly different approach, since there’s no existing keyword list of your own to compare against.

Skip straight to pulling competitor keyword lists, since your side of the comparison starts effectively empty.
Focus on lower-difficulty keywords first. A new domain has little to no authority yet, so competing for high-difficulty terms that established competitors rank for is usually not realistic in the short term.
Prioritize keywords where even mid-tier competitors rank outside the top 3, since these tend to be more achievable for a new domain to break into.
Build a foundational content cluster first, rather than chasing every gap at once. A smaller set of well-structured, interlinked pages tends to build authority faster than a scattered list of one-off articles.
Re-run the analysis every 60 to 90 days in the early stages, since a new site’s competitive position shifts faster than an established one.

Common Mistakes to Avoid

Comparing against the wrong competitors. Brand competitors and search competitors aren’t always the same list.
Ignoring search intent. A keyword gap doesn’t mean much if the top-ranking pages for that term are a format you don’t offer.
Treating every keyword as equal priority. Volume alone isn’t a strategy, difficulty and relevance matter just as much.
Running the analysis once and never repeating it. Competitor content strategies change. A gap list from a year ago is likely already outdated.
Skipping the export/spreadsheet step. Reviewing results inside the tool without exporting makes it harder to track progress or share the plan with a content team.

FAQ

1. What are the best free tools for basic competitive keyword research?

Ubersuggest and Google Keyword Planner are the two most practical free options. Ubersuggest offers a usable (if limited) competitor keyword view, and Keyword Planner fills in volume data reliably since it pulls directly from Google’s own ad platform data.

2. How often should I run a keyword gap analysis?

Quarterly is a reasonable default for most businesses. Fast-moving or highly competitive markets may benefit from checking every 60 days, while more stable niches can often go 6 months between full analyses.

3. I don’t have the time to run this myself, what are my options?

Several agencies offer keyword gap analysis as a standalone deliverable rather than requiring a full ongoing retainer. Incubate Growth runs this as part of its SEO audit process, with output scoped to be genuinely usable by a small in-house team rather than a report that sits unopened. It’s a reasonable option if the manual process outlined above isn’t a good use of your time right now.

Want the Strategy Behind the Steps?

This next guide covers the mechanics of pulling the data; the framework on how to prioritize what you find, turn it into a content plan, and track whether it actually worked.

How to Do a Keyword Gap Analysis: Step-by-Step With Free and Paid SEO Tools