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If you've ever tried to look up how much traffic a startup gets, you've probably run into three names: SimilarWeb, Ahrefs, and Trust Traffic.
They all claim to tell you about website traffic. But they're doing fundamentally different things — and confusing them leads to bad decisions.
This post breaks down exactly what each tool measures, where it gets that data, and which one you should be reaching for depending on what you actually need to know.
The Core Problem With Traffic Data
Website traffic is private by default. Companies don't have to share it. So any tool that claims to show you someone else's traffic is either estimating it — or collecting it from sources the site owner may not even know about.
That distinction matters enormously. Estimated traffic and verified traffic are not the same thing. One is inference. The other is ground truth.
SimilarWeb: Estimated Traffic at Scale
SimilarWeb is the best-known traffic intelligence tool on the market. It covers millions of websites and shows you estimated monthly visits, traffic sources, top pages, audience demographics, and more.
The operative word is estimated.
SimilarWeb builds its estimates from several data sources: browser extensions installed on users' computers, ISP-level data partnerships, clickstream data purchased from third parties, and machine learning models that extrapolate from all of the above.
For large, established websites — think e-commerce giants, media publishers, or well-known SaaS companies with millions of monthly visitors — SimilarWeb's estimates are often directionally accurate. They're good enough for competitive benchmarking at the macro level.
For startups, especially early-stage ones with fewer than 50,000 monthly visits, SimilarWeb is much less reliable. Small sample sizes mean high variance. Estimates can be off by 2x, 5x, or more. Some legitimate startups show as zero traffic. Others show inflated numbers.
SimilarWeb is best for: Competitive research on larger companies, understanding traffic mix and channel breakdown, tracking relative share-of-voice in your market.
SimilarWeb is not great for: Accurate data on early-stage startups, benchmarking your own traffic against peers at the same stage.
Pricing: Expensive. Enterprise plans run into the thousands per month. There's a limited free tier.
Ahrefs: Organic Traffic Estimates From SEO Data
Ahrefs started as a backlink analysis tool and evolved into a comprehensive SEO platform. One of its key features is organic traffic estimates for any website.
Here's how it works: Ahrefs crawls the web, indexes keywords, and tracks which websites rank for which search terms. It then multiplies a site's keyword rankings by estimated search volume and applies click-through-rate curves to estimate how much organic traffic that site receives from Google.
This is a completely different methodology from SimilarWeb. Ahrefs is measuring SEO traffic specifically — what it calculates as search-driven visits. It doesn't directly measure direct traffic, social traffic, email traffic, or paid traffic.
For startups whose primary growth channel is organic search, Ahrefs can be a useful proxy. If a startup is aggressively publishing content and ranking for meaningful keywords, Ahrefs will reflect that.
But Ahrefs doesn't know about:
- Direct traffic from brand awareness
- Traffic from newsletters or email
- Paid acquisition
- Social and referral
- Word-of-mouth driven visits
A startup with 20,000 monthly visits mostly from a viral product launch or an engaged Twitter following could show as near zero in Ahrefs.
Ahrefs is best for: SEO competitive research, understanding keyword opportunities, benchmarking your organic search footprint against competitors.
Ahrefs is not great for: Getting a complete picture of total traffic, benchmarking startups whose primary growth isn't SEO-driven.
Pricing: Starter plan from ~$29/month. Full-featured plans are $99–$999+/month.
Trust Traffic: Verified Startup Traffic
Trust Traffic takes a different approach entirely.
Instead of estimating traffic from external signals, Trust Traffic publishes data that founders have submitted themselves and verified through Google Analytics or Google Search Console.
No estimation. No inference. No extrapolation from clickstream data or SEO rankings.
When a startup's traffic appears on Trust Traffic, it means a real founder connected their real analytics and confirmed the numbers. The data you see is what's actually in their dashboard.
Right now, Trust Traffic has around 97 verified startups listed — a much smaller dataset than SimilarWeb or Ahrefs, which cover millions of sites. But the tradeoff is accuracy.
For early-stage founders specifically, this matters. The question "what does good traffic look like at pre-seed?" or "is 8,000 monthly visits at Series A typical or weak?" can't be answered by SimilarWeb (too inaccurate at small scale) or Ahrefs (too channel-specific). Trust Traffic is the only place that answers those questions with verified data.
Trust Traffic is best for: Benchmarking your startup's traffic against verified peers at the same stage, understanding what "normal" growth looks like across different startup stages, founders who want ground-truth data rather than estimates.
Trust Traffic is not great for: Research on large, established companies (it focuses on startups), competitive intelligence on companies that haven't submitted their data.
Pricing: Free to browse the leaderboard. $19/month for sponsored placement.
Side-by-Side Comparison
ㅤ | SimilarWeb | Ahrefs | Trust Traffic |
Data type | Estimated | Estimated (organic only) | Verified |
Coverage | Millions of sites | Millions of sites | ~97 startups |
Accuracy for early-stage startups | Low | Medium (organic only) | High |
Channels covered | All (estimated) | Organic search only | All (verified total) |
Best use case | Competitive research | SEO benchmarking | Startup benchmarking |
Pricing | $$$ | Free/$ |
Why Ahrefs and SimilarWeb Show Different Numbers for the Same Site
If you've looked up the same startup in both tools and got completely different figures, you're not imagining it. The methodology gap is real — and for startup-sized sites it can mean a 3–5× difference in the number each tool shows.
How SimilarWeb calculates traffic: SimilarWeb estimates all traffic channels — direct, organic, social, email, paid — by aggregating data from browser extensions installed on millions of users' computers, ISP-level data partnerships, third-party clickstream panels, and machine learning models that extrapolate from all of the above. For a website with millions of monthly visits, it may have tens of thousands of real data points and the extrapolation is reasonably accurate. For a startup with 5,000–50,000 monthly visits, it might have 20–200 actual panel observations and is filling in the rest with inference. At that scale, the estimates can overshoot or undershoot by 3–5×.
How Ahrefs calculates traffic: Ahrefs only measures organic search traffic. It crawls the web, indexes which keywords a domain ranks for in Google, then multiplies: ranking position × estimated search volume × expected click-through rate for that position. It sees nothing outside of Google organic: no direct visits, no newsletter clicks, no social traffic, no paid. A startup that gets 80% of its traffic from word-of-mouth, a viral launch, or an engaged email list will appear near-invisible in Ahrefs regardless of real traffic.
A concrete example: Take a startup with 20,000 real monthly visits:
- If most visits come from direct traffic and referrals: SimilarWeb might show 10,000–40,000 (extrapolation noise), Ahrefs might show 500–2,000 (just the organic slice).
- If most visits come from SEO: SimilarWeb might show 8,000–25,000, Ahrefs might show 14,000–20,000 (closer, but still not the same).
- In both cases, neither tool is reporting the real number.
Why this matters for startup benchmarking: This is exactly why using SimilarWeb or Ahrefs to benchmark early-stage startups produces misleading conclusions. "They have 50k visits and we only have 8k" might mean nothing — or everything — depending on methodology, channel mix, and the size of each tool's data panel for that specific site. Verified data, where the founder has connected their actual analytics, is the only way to make the comparison meaningful.
Which One Should You Use?
The honest answer is: it depends on what you're trying to do.
If you're doing competitive research on a larger company — a SaaS competitor you're trying to size up, or a market leader you're benchmarking against — SimilarWeb is the right starting point. Its estimates are meaningful at scale.
If you're planning an SEO strategy and want to understand what keywords your competitors rank for and how much traffic those keywords might send them, Ahrefs is the tool. It's the industry standard for SEO competitive intelligence.
If you're a startup founder trying to benchmark your own growth — figuring out whether your traffic at your current stage is ahead, behind, or in line with peers — Trust Traffic is the only tool built specifically for that. It's the only place where the traffic data is verified rather than estimated.
These tools aren't really competing. They answer different questions. The mistake is using SimilarWeb or Ahrefs to answer questions they weren't designed for — like assuming a startup's estimated traffic is accurate when you're trying to set your own growth targets.
The Benchmark Problem
One of the most common questions early-stage founders ask is: "How much traffic should I have at this stage?"
Neither SimilarWeb nor Ahrefs can answer that reliably. SimilarWeb's estimates break down at the scale most startups operate at. Ahrefs only sees the SEO slice.
Trust Traffic exists specifically to answer this question — because founders submitted their real numbers, you can actually see what verified traffic looks like at pre-seed, seed, Series A, and beyond.
If you're building a startup and want to know where you stand, that's the benchmark that matters.
