Estimating how much traffic someone else’s website receives is a common need in competitive analysis, due diligence, or sales prospecting. The practical question isn’t which tool exists, but how much it’s worth paying for data that, at best, is an estimate. According to the providers’ own documentation, no third-party tool accesses another website’s actual server logs: everything is inferred from user panels, extensions, ISP data, and statistical models.
What you can get for free (and how far it goes)
The no-cost alternatives rely on public sources or limited samples:
- Similarweb on its free plan: it offers a range of monthly visits and the channel breakdown, but with short time series and no keyword breakdown. For domains with fewer than a few tens of thousands of visits per month, the data usually appears empty or with such a wide range that it’s hardly actionable.
- Semrush and Ahrefs in trial mode or on basic plans: they let you check a limited number of domains per day. They’re useful for a one-off review, not for monitoring a dashboard of twenty competitors.
- Google Trends: it doesn’t give absolute figures, but it’s free and honest: it compares relative popularity. Useful for spotting seasonality, useless for budgeting a campaign.
- Your own Search Console: if the website is yours, this isn’t an estimate, it’s real data on impressions, clicks, and CTR. Many teams pay for third-party tools for their own domain when they already have the primary source available.
What justifies paying for a subscription
Paid plans provide three things that free access doesn’t sustain: history, granularity, and coverage. A specific case that comes up again and again at agencies: when preparing a proposal for a potential client, the free version shows a 40% drop in the competitor’s traffic and doesn’t let you tell whether it’s real or an artifact of the model. In the paid version you can see that the drop coincides with a domain migration and a loss of indexed pages. That difference in context is what you’re paying for.
In addition, paid plans include export, alerts, and breakdowns by country and device, essential if you’re going to make advertising investment decisions.
Mistakes I’ve seen in practice
The most common mistake is treating the data as an accounting figure. I’ve reviewed reports where the estimated traffic of two websites in different industries was compared without normalizing for seasonality, and the conclusion was the opposite of the real one. Another frequent mistake: relying on estimated traffic to calculate the value of a link. The tools calculate traffic from rankings and search volumes, so a site with a lot of social media or email traffic appears undervalued.
This doesn’t work for everything
No tool estimates well the traffic of websites with fewer than a thousand monthly visits, of intranets, of private dashboards, or of domains with aggressive bot blocking. Nor is it useful for measuring someone else’s conversions: that isn’t estimated, it’s inferred with far less reliability. And if you need auditable figures for a corporate transaction, the only solid route is to request access to the seller’s internal analytics.
How to decide in practice
If your use is sporadic and exploratory, stick with the free plan and supplement it with Trends and with public Search Console data when the domain is yours. If you need to compare several competitors on a recurring basis, with months of history and change alerts, the subscription pays for itself quickly. A little-known middle ground: several tools offer single-user plans with low limits that cover most of a small business’s queries and cost a fraction of the agency plan.
Final recommendation: always validate the estimate against an independent source (for example, the number of reviews, the traffic the site itself declares, or social media activity) before presenting the data as a fact.