Fathom Analytics vs PostHog
They differ on 9 of the 14 things buyers in this category actually ask about. Here is where, and what each one asks you to give up.
Privacy-first web analytics with unlimited retention and a fixed, predictable bill.
Strongest argument
Unlimited sites on one subscription, which suits agencies well
Biggest objection
No funnels beyond basic goal tracking
The simplest privacy-safe option, with a feature ceiling you will hit if you need behavioural analysis.
PostHog
UsageProduct analytics, session replay, feature flags and experiments in one open-source platform.
Strongest argument
Replaces four separate subscriptions — analytics, replay, flags and experiments
Biggest objection
Usage-based pricing across several products makes the bill hard to predict
Consolidates a whole toolchain, at the cost of a bill with several independently growing lines.
The differences that matter
Where they actually diverge
Only the rows where the two disagree. Everything they both do is listed below.
Cost
What each costs at 50 people
List price only. It ignores add-ons, seat minimums and the cost of the move itself — all of which routinely dwarf the difference below.
Prices are unverified estimates — useful for comparing orders of magnitude, not for budgeting. Confirm the current figure with the vendor before you commit to anything.
Common ground
What both of them do
These will not help you choose — which is exactly why they are worth knowing about before a vendor pitches one as a differentiator.
- Real-time reportingYes
- Raw data exportYes
- EU data residencyYes
- Public APIYes
- Native mobile appsNo
In full
Every pro and con, both sides
Fathom Analytics
- Unlimited sites on one subscription, which suits agencies well
- Cookieless and GDPR-compliant without a consent banner
- Data is retained forever rather than expiring after a year
- No funnels beyond basic goal tracking
- Not a product-analytics tool — there is no user-level analysis
- Fewer integrations than the larger platforms
PostHog
- Replaces four separate subscriptions — analytics, replay, flags and experiments
- Generous free tier that real products can run on for a long time
- Open source and self-hostable, so data residency is your decision
- Usage-based pricing across several products makes the bill hard to predict
- Aimed at product teams — marketers will find it unfamiliar
- Self-hosting is only supported at meaningful scale on Kubernetes
Questions
Fathom Analytics vs PostHog, answered
Fathom Analytics or PostHog — which is better?
Neither, in the abstract. Fathom Analytics suits you if unlimited sites on one subscription, which suits agencies well matters most; PostHog if replaces four separate subscriptions — analytics, replay, flags and experiments does. The honest trade-offs are: Fathom Analytics — The simplest privacy-safe option, with a feature ceiling you will hit if you need behavioural analysis. PostHog — Consolidates a whole toolchain, at the cost of a bill with several independently growing lines.
Is Fathom Analytics cheaper than PostHog?
At least one of them is priced on usage rather than headcount, so there is no honest like-for-like figure. Model both against your own volume — contacts, events or tickets — before comparing, because the headline numbers measure different things.
Can we migrate from Fathom Analytics to PostHog?
Usually yes, and the difficulty depends on history, integrations and headcount far more than on the two products. Data export quality is the thing to check first: ask both vendors what you can take with you before you commit to either. Our questionnaire produces a scoped estimate for the move.
What else should we consider besides Fathom Analytics and PostHog?
In product & web analytics the other credible options are Google Analytics 4, Matomo, Plausible. Narrowing to two before you have written down your requirements is the most common way to end up with the wrong one.
Do not stop at two