Companies Using Fathom

This analysis reads the September 2026 data on this page: 24,423 domains detected running Fathom Analytics, 15,191 of them matched to a company record (62.2%), and 1,735 more that carried a detection and no longer do. That match rate is high for a product of this size, and it is the main reason the demographic charts here are worth reading at all: a 62.2% matched base supports a distribution claim in a way a 20% one does not.

Read the change in the headline before you read the headline

This profile was re-identified in September 2026. It previously sat on an older technology identifier and reported 16,233 domains; it now sits on the live identifier for Fathom and reports 24,423. That is not fifty per cent growth. The two counts come from different detection systems, with different rulesets, different crawl coverage and different windows, and subtracting one from the other produces a number that means nothing. If you cited the old figure, replace it rather than treating the gap as a trend.

The current rule is worth stating plainly, because it decides what a customer means on this page. A domain qualifies when the crawl sees the JavaScript global fathom.blockTrackingForMe or a script loading from cdn.usefathom.com/. Both clauses are vendor-owned and both describe the tracker actually running in the page. That is a stronger claim than many technology detections can make: no DNS record that outlives the subscription that created it, no outbound link to a vendor's website, no payment badge in a footer. When this page says 24,423 domains, it means the Fathom script loaded.

0.13% is a statement about the denominator

Fathom holds 0.13% of the Web Analytics category and ranks 26th. The category holds roughly 18.2 million domains and Google Analytics is on 11,453,947 of them (62.77%), about 469 times Fathom's footprint. Site Kit, the WordPress plugin whose main job is installing Google Analytics, adds 3.54%, so Google's own surfaces are 66.31% of the category. Cloudflare Browser Insights, a switch inside an account a site already holds, is second at 11.34%.

Every one of those is free at the point of use. Fathom is not: it is a subscription with no free tier (usefathom.com/pricing). A paid product measured by domain share against free defaults will always look small, and the ratio flatters nobody on either side. The number that carries information about this business is not the share, it is the 24,423 domains and how many of them stay.

Who actually runs it

The distribution is unusually concentrated. 67.09% of sized companies employ ten people or fewer and 88.92% employ fewer than fifty. Only 54 companies in the whole matched base have more than five thousand staff. On founding dates, 60.65% of dated companies were founded in 2010 or later. On industry, Software Development (5.82%), Technology and Internet (4.51%) and IT Services (4.19%) are the three largest at 14.52% together, with Advertising (3.21%) and Business Consulting (3.12%) behind them.

Geography is where it gets interesting. The United States (5,039) and the United Kingdom (2,662) are just over half the matched base, which is unremarkable. The shape underneath is not: the Netherlands (800) outranks Canada (714), and Norway (458) and Belgium (413) both outrank France (383) and Australia (346). Small, wealthy, tightly regulated European markets are over-represented relative to their size, and Fathom's EU isolation — EU visitor data processed on servers in Germany, per usefathom.com — is a direct answer to exactly that buyer's problem.

The co-occurrence table disagrees with itself, usefully

Co-occurrence is measured against the 24,527 domains live in the September crawl rather than the 24,423 in the rollup, so those percentages will not divide evenly into the headline. On that base, jQuery appears on 62.94% and WordPress on 39.36%: the established CMS web. But Tailwind CSS appears on 29.6%, less than ten points behind WordPress, with core-js on 33.47%. Those two readings describe different websites and both are real — Fathom's base is genuinely split between plugin-installed WordPress sites and hand-built modern front ends. The firmographics lean towards the second: micro-companies, founded since 2010, in software and design.

The number I would put in front of a strategist, though, is this one. 40.75% of live Fathom domains also run Google Analytics, and 43% run Google Tag Manager. Two in five sites running the product Fathom defines itself against are running both of them. That is coexistence, not conversion: a team keeping Google Analytics for historical continuity, or trialling Fathom in parallel before committing. It reframes the sales motion, because on most of these domains the competitor has not actually been displaced.

Retention, and what 7.1% does not prove

1,735 domains have dropped their Fathom detection against 24,423 that still carry it, a 7.1% churn ratio. For a paid tool a drop is a real event: somebody stopped paying, or pulled the tag. Two caveats before anyone quotes that as a retention benchmark. First, coverage of Fathom in this detection cluster only began in March 2026, and a six-month observation window mechanically produces a lower churn ratio than a two-year one, so this figure is not comparable with ratios measured over longer windows. Second, churn ratios for analytics tags are often inflated by consent gating, because a tag that fires only after a cookie banner is accepted appears and disappears depending on what the crawler was served; Fathom is cookie-less and generally loads without a banner, so its ratio should be less polluted by that effect than a cookie-based competitor's. Both caveats point the same way: treat 7.1% as a floor on this window, not as a measured annual churn rate.

Why this page publishes no migration corridor

It would be easy to write that Fathom users are switching to or from something, and the migration block on this profile is deliberately empty instead. A corridor is only meaningful between products that cannot coexist, two WordPress SEO plugins for instance. Analytics tags coexist by default, and the 40.75% Google Analytics overlap demonstrates it on this very base. Where the domains that dropped Fathom went is mostly invisible to us as well: a site that removes an analytics tag and installs nothing emits no signal, and a self-hosted replacement emits nothing we can attribute to a vendor.

The company list is smaller than it looks

The fifty companies listed on this page are the largest matched records, not a sample, and two structural caveats apply. Seventeen of the fifty are detected on a subdomain rather than a main hostname: developer.ibm.com, investors.danaher.com, brand.hashicorp.com, blog.railway.com, video.liverpoolfc.com, recruitment.cardiffmet.ac.uk, myplace.cuyahogacounty.gov and ten others. Those are departmental deployments — a developer portal, a brand site, a records portal — not enterprise analytics rollouts. And ten of the fifty rows belong to three corporate groups: Danaher plus four of its operating companies (Beckman Coulter twice, Pall and SCIEX), Menasha plus its ORBIS subsidiary, and Microchip plus Microsemi. One procurement decision can produce five rows in a list like this, which is why a logo wall is a poor proxy for enterprise penetration.

What to take away

• The headline moved from 16,233 to 24,423 because this page was re-identified, not because the product grew by half.
• The detection is vendor-owned JavaScript, so every counted domain actually loaded the tracker.
• 0.13% of the category reflects a market where 66.31% of domains carry a free Google surface; the base worth reasoning about is the 24,423 paid domains.
• 67.09% of sized companies employ ten people or fewer, and only 54 exceed five thousand.
• Small European markets are over-represented — Norway and Belgium each ahead of France — which matches the EU isolation pitch exactly.
• 40.75% of live Fathom domains also run Google Analytics: this market coexists rather than switches.
• 7.1% of the base has dropped its detection since March 2026, over a short window, so read it as a floor.

If you sell to this base

The addressable segment here is a micro-business that already pays for software it could have for free, which is a useful qualifying signal on its own. Target by stack rather than by size: the Tailwind CSS and core-js share of the base is a developer-led buyer and the WordPress and Elementor share is an agency-led one, and the two do not respond to the same message. For anyone selling analytics, the 40.75% running Google Analytics alongside Fathom are the honest opportunity, because they have already shown they will run two tools at once.