Web Analytics · Comparison
Fathom Analytics vs. PostHog
Fathom Analytics and PostHog compared across Company facts, Pricing, Analytics capabilities, Privacy & compliance, Data ownership & deployment and Platform & integrations — every fact sourced and re-verified from each vendor's public material.
Fathom Analytics
Privacy-first, cookieless web analytics with a simple dashboard and forever data retention.
PostHog
All-in-one open-source platform for product analytics, web analytics, session replay, and feature flags.
Company facts
Headquarters
Victoria, Canada Fully remote-first company; Victoria, BC is the legal incorporation location.
San Francisco, CA PostHog is incorporated in San Francisco, CA but is a remote-first company with team across 20+ countries.
Employees
5 LinkedIn shows 2–10 employees; 3 listed profiles. Midpoint of visible data ~5.
202 Approximately 202 employees as of May 2026 per Tracxn; ~185 per April 2026 LinkedIn data.
Pricing
Starting Monthly Price (USD)
$15 Entry plan: $15/month for up to 100k pageviews.
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Offers Free Tier
7-day free trial available; no perpetual free plan.
PostHog offers a perpetual free tier: 1M events/month at no cost, no credit card required, no expiry.
Free Trial Length (Days)
7 days 7-day free trial on all paid plans.
0 days No free trial period — PostHog provides a perpetual free tier instead of a time-limited trial.
Entry Plan Pageview Limit (Monthly)
100k Entry plan ($15/mo) includes up to 100k pageviews/month.
1M Free tier includes 1M events/month. PostHog meters 'events' (not raw pageviews); each pageview fires as one event.
Entry Plan Website Limit
50 sites Up to 50 sites included on all plans; additional sites purchasable.
6 sites 6 projects on the paid (pay-as-you-go) plan; PostHog tracks per project. Free plan includes 1 project.
Analytics capabilities
Real-Time Dashboard
Dashboard updates in real time; also provides a current-visitors API endpoint.
PostHog's web analytics dashboard includes real-time data with live visitor activity.
Custom Event Tracking
Custom events tracked via fathom.trackEvent() JS call or data attributes.
PostHog supports custom event tracking via JS SDK (posthog.capture()), autocapture, and data attributes.
Goal / Conversion Tracking
Goals are built on custom events with conversion-rate reporting.
Web analytics dashboard supports conversion goals: define a key event or action, see total/unique conversions and conversion rate.
Funnels
Multi-step funnel analysis is not a feature; no documentation or marketing page references it.
PostHog supports multi-step funnels with step-to-step drop-off analysis, breakdowns, and timings.
Ecommerce / Revenue Tracking
Revenue values (in cents) can be attached to custom events; Shopify integration supported.
PostHog supports revenue tracking: capture monetary values on events, Stripe integration, currency conversion, MRR/ARPU dashboards.
Heatmaps
Heatmaps are not part of the product.
PostHog includes click heatmaps, scroll maps, and rage-click detection as part of the platform (toolbar overlay).
Privacy & compliance
Cookieless Tracking
Zero cookies used by design; visitor identification via daily-salted SHA256 hashing.
PostHog supports cookieless tracking mode (cookieless_mode: always) where no persistent ID is stored in the browser.
Consent Banner Required
Vendor explicitly states no cookie consent banner is needed when using Fathom.
Default PostHog configuration uses cookies/localStorage and requires a consent banner. Cookieless mode removes the requirement but is not the default.
GDPR Compliant
Vendor explicitly claims GDPR compliance; conducted formal GDPR review with EU consultants.
PostHog explicitly claims GDPR compliance with EU Cloud hosting, DPA, cookieless option, and data anonymization.
EU Data Residency
EU Isolation strips visitor IPs inside the EU, but the anonymized analytics data is stored on Fathom's main US servers.
PostHog Cloud EU stores all data in AWS eu-central-1 (Frankfurt, Germany). Available at no extra cost.
Data ownership & deployment
Open Source
Fathom is a closed-source, proprietary cloud SaaS product.
PostHog is open source under MIT license (with a proprietary EE directory). A fully FOSS mirror (posthog-foss) is also published.
License
proprietary Current flagship product is closed-source; an archived MIT-licensed v1 exists but is not the offered product.
MIT Core product is MIT-licensed; /ee directory with enterprise features uses a separate proprietary license.
Self-Hostable
Cloud-only SaaS; no self-hosting option documented or advertised.
PostHog supports self-hosting via Docker Compose with documented install guides. Free for self-hosters.
Data Retention (Months)
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84 mo Paid plans retain event data for 7 years (84 months); after 1 year data may move to cold storage (slower queries).
Unlimited Data Retention
Vendor advertises 'forever' data retention on all plans.
Data retention is 7 years (84 months) on paid plans — finite, not unlimited.
Google Analytics Import
GA4 data import supported; Universal Analytics not supported (Google deleted UA data July 2024).
PostHog documents a GA-to-PostHog migration path via BigQuery export + Python SDK import, with official step-by-step docs.
Raw Data Export
Export is aggregated CSVs (dashboard reports); no raw visit/event-level data export available.
PostHog supports raw event-level data export via Exports API, batch exports to S3/Postgres, and real-time pipeline destinations.
Platform & integrations
Has API
Public Stats API for aggregated reporting plus account/site/event management endpoints.
PostHog provides a comprehensive REST API for querying analytics data, dashboards, exports, and more.
Tracking Script Size (KB)
2 KB Measured compressed transfer size.
66.7 KB Initial array.js payload; PostHog lazy-loads additional modules.
Official WordPress Plugin
Official vendor-published WordPress plugin available at wordpress.org/plugins/fathom-analytics/.
No official PostHog-published WordPress plugin. PostHog docs describe manual snippet insertion; multiple third-party community plugins exist.
Email Reports
Weekly or monthly scheduled email reports available.
PostHog supports scheduled email subscriptions for dashboards and insights (weekly, monthly, or custom schedule).
Public Dashboard Sharing
Dashboards can be shared publicly or via password-protected link.
PostHog supports fully public dashboard sharing via a shareable link, no account required to view. Embeddable via iframe.
The verdict
Fathom Analytics Best for lightweight, consent-free privacy analytics
Fathom is cookieless by design and states no consent banner is needed, where PostHog's default config requires one. Its 2 KB script is far lighter than PostHog's 66.7 KB payload, retention is unlimited rather than capped at 84 months, and the entry plan covers 50 sites vs 6. An official WordPress plugin ships; PostHog has none.
Full profile PostHog Best for free, self-hosted, deep product analytics
PostHog runs a perpetual free tier (1M events) and is MIT-licensed and self-hostable, while Fathom is proprietary, cloud-only, and starts at $15/mo with no free tier. It adds funnels, heatmaps, and raw event-level export that Fathom lacks, plus EU data residency in Frankfurt where Fathom stores analytics data on US servers.
Full profileSources · 38 verified references
usefathom.com posthog.com linkedin.com tracxn.com github.com cdn.usefathom.com + 1 more
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