Rankfill

Competitor Tools That Show You Exactly What to Publish

You open your analytics on a Tuesday morning and notice a competitor you barely thought about is now outranking you for a dozen terms you care about. You search one of those keywords yourself, read their article, and think: we could have written that. You probably should have. Six months ago. Before they indexed 40 pages on topics you haven't touched.

That's the moment people start looking for competitor tools — not out of abstract curiosity about the market, but because something specific just stung.

The problem with most competitor tool roundups is they show you a list of platforms with screenshots and pricing tables. They don't tell you what each tool is actually good at, where each one falls apart, or which one gets you from "my competitor is beating me" to "here's the article I need to write by Friday." That's what this covers.

What You Actually Need a Competitor Tool to Do

Before comparing tools, get clear on what you're trying to accomplish. Most people searching for competitor tools have one of three jobs to do:

  1. Find keywords competitors rank for that you don't — so you can build content that captures that traffic
  2. Understand why a competitor ranks — backlink profile, domain authority, content depth, site structure
  3. Get a prioritized list of what to publish — not just data, but a decision

The first two are table stakes. Every major tool covers them. The third is where tools diverge sharply, and it's the one that actually matters if your goal is growing organic traffic rather than collecting insights.

The Main Competitor Tools, Compared Honestly

Ahrefs

Ahrefs is the most widely used tool for competitor keyword research, and for good reason. The Site Explorer is genuinely excellent — paste in a competitor's domain, filter by organic keywords, sort by traffic, and you get a clean view of what's working for them.

The Content Gap feature is where it gets specifically useful for deciding what to publish. You enter your domain and up to five competitors, and it surfaces keywords they rank for that you don't. You can filter by keyword difficulty, search volume, and how many competitors are ranking for it (the more that are, the more validated the opportunity).

Where it excels: Backlink data is the best in the industry. Content gap analysis is fast and filterable. Keyword Explorer gives you solid volume and difficulty estimates.

Where it falls short: The data is rich but the interpretation is yours. Ahrefs tells you what keywords exist — it doesn't prioritize them for your specific situation or generate a content plan. You still have to make every editorial decision yourself.

Pricing: Starts around $129/month. No free tier for meaningful competitive research (the free version is limited to a few searches).

Semrush

Semrush has more surface area than Ahrefs — it covers competitor analysis, keyword research, on-page SEO auditing, backlink research, PPC data, and social. If you're an agency managing multiple clients across different channels, that breadth is useful. If you just want to find content gaps, it can feel like navigating a department store to buy one specific thing.

The Keyword Gap tool is comparable to Ahrefs Content Gap — you compare domains and surface opportunities. Semrush also has an Organic Research section that shows a competitor's top pages by estimated traffic, which is useful for understanding what content formats are driving their growth.

Where it excels: Topic Research and Keyword Magic Tool are genuinely good for ideation. The Traffic Analytics feature estimates a site's total traffic with a breakdown by channel.

Where it falls short: Volume and difficulty estimates sometimes diverge from Ahrefs in ways that are hard to reconcile. The UI has improved but is still cluttered compared to Ahrefs. And like Ahrefs, it produces data — not decisions.

Pricing: Starts around $139/month.

Moz Pro

Moz built its reputation on domain authority (DA), a metric that's now so widely referenced that people sometimes treat it as official. The Keyword Explorer and Link Explorer are solid tools, but Moz has fallen behind Ahrefs and Semrush on data freshness and breadth.

The True Competitor feature identifies sites competing with you for the same keywords — useful if you're not sure who you're actually competing with in search. The Keyword Gap analysis exists but is less granular than the alternatives.

Where it excels: Domain Authority is still a useful relative scoring metric. Good for agencies that need a simple, explainable number for clients.

Where it falls short: Data is thinner than Ahrefs and Semrush. Not the right choice if content gap analysis is your primary use case.

Pricing: Starts around $99/month.

Similarweb

Similarweb's strength is traffic estimation and channel breakdown rather than keyword-level research. It's excellent for understanding how much organic traffic a competitor gets, what share comes from search versus direct versus referral, and which countries they're strongest in.

It's less useful for finding specific keywords to target. The keyword data exists but isn't as deep or actionable as Ahrefs or Semrush.

Where it excels: High-level competitive intelligence. Useful for market sizing and understanding traffic composition.

Where it falls short: Keyword-level content gap analysis is not its strong suit. If you want to know what articles to write, Similarweb won't get you there.

Pricing: Free tier available with limits. Paid plans start around $125/month for meaningful data.

SpyFu

SpyFu is underrated for PPC research and has decent organic keyword data. It's specifically designed around competitor intelligence — you enter a competitor's domain and it shows you every keyword they've ever ranked for, going back years.

The historical data is SpyFu's real differentiator. If you want to understand how a competitor built their organic presence over time — which keywords they started with, what they prioritized — SpyFu shows you that story in a way other tools don't.

Where it excels: Historical keyword tracking. Identifying long-term content plays by competitors. PPC competitive research.

Where it falls short: Content gap analysis is less sophisticated than Ahrefs or Semrush. Data is less fresh. Interface feels dated.

Pricing: Starts around $39/month, which makes it the most accessible option for solo operators.

Screaming Frog

Screaming Frog is a crawler, not a keyword research tool, but it belongs in any conversation about competitive research because it gives you something the keyword tools don't: a full structural view of what a competitor has published.

You can crawl a competitor's site and see every indexed URL, how pages are internally linked, what meta titles and descriptions look like, page depth, redirect chains, and more. Paired with a keyword tool, it's a powerful combination — you find the keywords you're missing and then understand exactly how the competitor structured the content that's capturing them.

If Screaming Frog's limitations are a factor for you, there are Screaming Frog alternatives for content gap analysis worth considering depending on your workflow.

Where it excels: Technical site structure analysis. Understanding a competitor's content architecture.

Where it falls short: No keyword data on its own. Requires pairing with another tool to be useful for content planning.

Pricing: Free version crawls up to 500 URLs. Paid license is around £199/year.

Google Search Console (Your Own Data, Not Competitors')

Not technically a competitor tool, but it's worth including because people sometimes overlook the data they already have. GSC shows you what queries your site is already appearing for, your average position, and click-through rate.

Where this matters for competitor research: if you're ranking positions 8–20 for a keyword, you're in the game but not winning. That's not a competitor gap — that's a content improvement opportunity. Knowing the difference changes how you prioritize.

How to Actually Use These Tools to Decide What to Publish

Having access to data is not the same as having a content plan. Here's a process that works:

Step 1: Identify your real competitors. Not business competitors — search competitors. A company selling similar products isn't your search competitor if they're in a different niche. Use Ahrefs' Competing Domains or Semrush's Organic Research to find which sites are ranking for the same keywords you currently rank for.

Step 2: Run a content gap analysis. In Ahrefs, use Content Gap. In Semrush, use Keyword Gap. Enter 3–5 of your identified search competitors. Filter results to keywords where at least 2–3 of them rank but you don't. This narrows the list to validated opportunities — topics with proven traffic that the market has already decided matter.

Step 3: Filter by keyword difficulty and volume. If your site has strong domain authority, filter for medium-difficulty keywords (KD 30–60) with meaningful search volume. If you're earlier in building authority, stay under KD 30. Ignore vanity keywords with high volume but no commercial relevance.

Step 4: Cluster by topic. You'll notice patterns — a competitor might have 12 articles about a topic you've written one piece on. That's a signal about depth, not just individual keywords. Group related keywords together and think about them as a topic cluster rather than isolated articles.

Step 5: Prioritize by business value. A keyword that gets 500 searches/month from people who would buy your product beats a keyword with 5,000 searches from people who never would. Layer in business context that the tools can't provide.

If you want to go deeper on the actual mechanics of this process, how to analyze competitors and steal their keywords walks through it step by step.

The Gap Between Data and a Published Article

Here's the honest problem with every tool on this list: they get you to a list of keywords. They do not get you to a published article.

The path from "keyword identified" to "content ranking" involves deciding on the angle, outline, word count, internal linking strategy, who writes it, what the deadline is, and whether the output actually matches search intent. Tools measure the gap. Closing the gap requires a process.

Some teams solve this with a dedicated content strategist who can take tool output and turn it into briefs. Others use freelancers or agencies. If you want a service that maps competitor opportunities and then actually deploys content based on them, Rankfill does exactly that — identifying which keywords competitors are capturing that your site is missing and building the content plan around it.

The bigger point: don't mistake having the right tool for having a content operation. The tool tells you where the money is buried. Someone still has to dig.

Which Tool Should You Actually Use?

If you're choosing one tool for competitor keyword research and content gap analysis:

Most serious operators use two: a keyword tool (Ahrefs or Semrush) plus a crawler (Screaming Frog) for competitive site audits. That combination covers both the keyword opportunity and the structural understanding of how competitors built the content that captures it.

If you want to go further on the structural side, analyzing a competitor website for SEO gaps covers what to look for beyond keyword data. And if you're approaching this for the first time and want a systematic framework, competitor analysis for any website: tools and tactics is a good starting point.

FAQ

Is Ahrefs or Semrush better for competitor research?

For keyword-level competitor research and content gap analysis specifically, Ahrefs has a cleaner workflow and the data is highly reliable. Semrush covers more ground but requires more navigation. If you're focused on SEO content decisions, most practitioners prefer Ahrefs. If you need PPC competitive data alongside SEO, Semrush is the better choice.

Can I do competitor keyword research for free?

You can get partial data free. Ahrefs and Semrush both offer limited free searches. Google Search Console gives you your own site's data. Ubersuggest has a free tier with basic competitor keyword data. For serious content gap analysis across multiple competitors, you'll hit the limits of free tools quickly. SpyFu at $39/month is the most affordable paid option worth using.

How do I know which competitor keywords are worth targeting?

Filter for keywords where: (1) at least 2–3 competitors rank in the top 10, (2) your domain could realistically compete based on your current authority, and (3) the keyword is topically relevant to what your site is about. High volume alone is not a signal — match search intent to what you can actually deliver.

How often should I run competitor analysis?

At minimum, quarterly. Competitor content strategies shift, new sites enter your space, and your own position changes. If you're actively publishing content, run it monthly so you can spot emerging opportunities before competitors own them.

What's the difference between a keyword gap and a content gap?

A keyword gap is a specific term a competitor ranks for that you don't. A content gap is broader — a topic or cluster of related keywords they've covered that you haven't addressed at all. Content gaps usually contain multiple keyword gaps. Working at the content gap level is more strategic and leads to more durable results than chasing individual keywords one at a time.

Do I need to match a competitor's word count to outrank them?

Not necessarily. Word count isn't a ranking factor. What matters is whether your content fully satisfies the search intent for that keyword. A competitor might rank with 3,000 words because that's what's needed to cover the topic. Or they might rank with 800 words because the query is simple and focused. Study the content that ranks, not just the length.

What if I can't afford any of these tools?

Start with the combination of Google Search Console (free, your own data) and the free tiers of Ahrefs and Semrush for competitor peeks. You'll burn through free searches quickly, but you can identify 10–20 real content opportunities before hitting the wall. Once you've validated the process is working for you, a paid subscription pays for itself quickly.