Competitive keyword research means listing the search terms your competitors rank for that you don’t, then choosing the few you can realistically win. You can do it for free with Search Console, Google Keyword Planner and a few manual searches, or in minutes with a gap report in Semrush or Ahrefs, whose paid plans start at $139 and $129 a month.
The tools are the easy part. Most gap reports return hundreds or thousands of keywords, and the real work is cutting that list down to the ten that fit your business, match a page you can actually write, and aren’t owned by sites you can’t outrank. This guide covers both halves: how to get the list, and how to pick from it. Tool features and prices were checked against each vendor’s own pages in October 2026.
The three kinds of keyword gap
A “gap” is not one thing. Semrush’s Keyword Gap documentation splits it into categories that are worth knowing even if you never use Semrush, because each one calls for a different action.
Weak keywords are often the fastest win, and most guides skip them. Google already connects your site to the topic. Improving an existing page is usually less work than writing and indexing a new one.
Step 1: find your search competitors, not your business ones
The company across town that you lose bids to is your business competitor. Your search competitors are whoever shows up on page one for the terms your customers type, and for informational searches that is often a trade publication, a directory, a big-box retailer’s guide or a forum, not the shop down the road.
Running a gap report against the wrong domains gives you the wrong list. A national chain’s keyword set is full of brand terms and product pages you will never compete for.
To build the right list:
- Write down 10 to 15 searches a customer would type before they need you. For an HVAC company: “furnace short cycling”, “how often to change furnace filter”, “heat pump vs furnace ohio”.
- Search each one in a private browser window and note every domain in the top 10.
- Count how often each domain appears. Anything that shows up for four or more of your searches is a real search competitor.
- Drop sites you can’t learn from: Wikipedia, YouTube, Reddit and giant retailers. They rank on authority, not on a keyword strategy you can copy.
- Keep three to five domains that are roughly your size or a little bigger.
Step 5 matters most. A site with ten times your links ranks for things you won’t reach this year, so its keywords make a discouraging list rather than a useful one. A competitor slightly ahead of you shows what is achievable next.
The free method: Search Console, Keyword Planner and manual checks
You can do a decent competitive keyword analysis without paying for anything. It is slower and less complete, but for a local business or a new site it is often enough.
Start with your own Search Console data
Your weak keywords are already in Google Search Console. Open the Performance report, select the Queries tab, and turn on Average position. Sort by impressions and look for queries where your position is between about 8 and 20. Those are searches where Google sees you as relevant, but a competitor’s page is preferred.
Google defines average position as the average position of the topmost result from your site, so a page sitting at 12 is usually on page two. For each of those queries, search it yourself and read the pages above you. You will usually see the gap within a minute: their page has a price table, a step list or a section you don’t.
Search Console can also filter queries with regular expressions. A filter such as ^(how|what|why|can|should) shows question searches, which are often the easiest to answer with a new section. If you want to report on progress later, our SEO reporting template shows how to track these queries month to month.
Pull ideas from a competitor’s site with Keyword Planner
Google’s Keyword Planner has a Start with a website option: you enter any URL, and Google looks for keywords related to that page’s content. Paste a competitor’s best service page or blog post and you get a list of terms Google associates with it, with monthly search estimates.
It needs a Google Ads account, and Google says you must complete account setup with billing information before you can use keyword ideas. You don’t have to run ads. Two limits: it shows what the page is about, not what it actually ranks for, and it has no keyword difficulty score.
Check what a competitor has published
Search site:competitor.com plus a topic word (for example site:example.com furnace) to see which pages Google returns on that topic. Google’s documentation for the site: operator warns that it doesn’t necessarily return every indexed URL, so treat it as a sample, not an inventory. Their blog archive or sitemap gives you the rest.
The paid method: gap tools
Paid tools estimate the rankings of any domain, so you can compare yours against competitors directly. Here is how the main options compare.
| Tool | What you compare | Gap view | Starting price (US, monthly billing) | Best for |
|---|---|---|---|---|
| Semrush Keyword Gap | Your domain plus competitors, up to five domains in all | Missing, Weak, Untapped, Strong, Shared, Unique tabs | Paid plans from $139 (pricing); free plan has 10 reports a day | Sorting gaps by type in one report |
| Ahrefs Content Gap | Your site against up to 10 competitors | Keywords they rank for and you don’t | $129 Lite (pricing); Ahrefs Free covers verified sites only | Comparing a wider set of rivals |
| DataForSEO Domain Intersection | Two domains per request | Keywords one domain ranks for and the other doesn’t | Pay per request, about one cent in its docs’ sample | Developers building their own reports |
| Keyword Planner | One URL at a time | None, ideas only | Free with a Google Ads account | Topic ideas from a specific page |
| Search Console | Your own site only | Your weak keywords | Free | Finding pages that nearly rank |
A few details from the vendor docs are worth knowing before you pay. Semrush defines Missing as keywords every competitor ranks for and you don’t, and Untapped as keywords at least one competitor ranks for and you don’t, so Untapped is always the longer list. Ahrefs lists Content Gap under Competitive Analysis in its top menu, and its free tier, Ahrefs Free (formerly Ahrefs Webmaster Tools), requires you to verify ownership before using Site Explorer, so it won’t show you a competitor’s full keyword set.
For a one-off project, a single month of either paid tool is usually enough. Run the reports, export them, and cancel if you don’t need ongoing tracking.
How to pick which gaps to chase
A gap export for a small business against three competitors can easily run to a few thousand rows. Almost all of them should be thrown away. Run every keyword through the same four filters, in this order.
Would a customer type it? Remove anything containing a competitor’s brand, their staff names or their location if it isn’t yours. Remove topics they cover that you don’t offer. If a rival HVAC company ranks for “commercial refrigeration repair” and you only do homes, that gap is not yours.
Can you make that page? Search the keyword and look at what ranks. If the top results are all product category pages and you planned a blog post, you won’t rank. If they are all calculators or tools, decide whether you can build one. Match the format Google already prefers.
Can you outrank page one? Keyword difficulty scores help here, but each tool calculates them differently, so compare scores within one tool only. The quicker test is to look at the top 10 for at least one or two sites your size. If page one is all national brands and government sites, move on for now.
Is it close to a sale? “Furnace making a clicking noise” is someone with a problem you can fix this week. “When was the furnace invented” is someone doing homework. Both may show up as gaps. Only one is worth your time.
Then group what’s left. Many gap keywords are different wordings of the same question, and one good page answers all of them. Two keywords one article would answer are one target, not two.
What a cleaned-up shortlist looks like
The numbers above are invented, but the shape is typical: the final list is a tiny fraction of the export. That is the point. Twelve pages you can actually finish and rank are worth more than a spreadsheet of two thousand keywords nobody opens again.
Turning the shortlist into a plan
Put each group in a simple sheet with five columns: the main keyword, the variants it covers, whether it needs a new page or an improved one, the competitor page that ranks now, and what your page will add that theirs lacks.
That last column is where you win. Copying a competitor’s page gets you a second copy of the same page, and Google has no reason to prefer it. Look for what you know that they didn’t write down: your actual prices, the local permit rules, the mistake you see on every second job. If you use AI to draft pages from the shortlist, give it those notes, or you end up with the generic result described in our AI content workflow write-up.
Order the work by effort, not by search volume. Weak keywords first, because the page exists. Then Missing keywords, because every competitor ranking for them suggests the topic is expected. Then the best of the Untapped list.
For local businesses, competitive research also applies to the map results, not only the blue links. If a rival outranks you there, the gap is usually in the Google Business Profile, reviews or citations rather than keywords. Our first-week local SEO plan covers those.
Mistakes that waste a gap analysis
- Comparing against a giant. A gap report against a national brand returns thousands of keywords you can’t win. Pick competitors near your size.
- Trusting volume estimates too much. Every tool’s search volume is an estimate. Use it to compare keywords, not to forecast traffic.
- Mixing difficulty scores from different tools. A 30 in one tool is not a 30 in another.
- Ignoring Weak keywords. Pages that already rank on page two are often the cheapest gains you have.
- Running it once. Competitors publish new pages. Repeat the analysis every three to six months, and check your Search Console positions monthly.
FAQ
Is there a free tool for competitor keyword research?
Not a complete one. Search Console shows your own weak keywords for free, Keyword Planner gives ideas from any competitor URL once you set up a Google Ads account, and Semrush’s free plan allows 10 reports a day, which is enough for a small test.
How many competitors should I compare?
Three to five. Semrush’s Keyword Gap takes five domains including yours and Ahrefs Content Gap takes up to 10 competitors, but more domains mostly add noise unless they are all genuine search competitors close to your size.
What is the difference between a keyword gap and a content gap?
The terms are used loosely and often mean the same thing. A keyword gap is a list of search terms competitors rank for and you don’t, and a content gap is the topics or pages behind those terms that your site is missing.
How often should I redo competitive keyword research?
Every three to six months for most small businesses, or when a new competitor starts showing up above you. Check Search Console positions monthly in between, since that catches slipping pages sooner.
Where to start
If you do one thing this week, open Search Console, find the queries where you sit between positions 8 and 20, and compare your page with the ones above it. That costs nothing and usually turns up a few fixes right away. Once those are done, find your real search competitors from the results page, run one gap report, and cut it down to a dozen pages you can actually finish.
