What is the difference between Fathom and PostHog?

Fathom is best for Businesses that want simple analytics without privacy headaches, while PostHog is best for Product teams that need analytics, session replay, and feature flags in one tool. Fathom starts at $14/mo and PostHog starts at Free.

Is Fathom or PostHog cheaper?

Fathom starts at $14/mo. PostHog starts at Free and is free.

Is there a free alternative to Fathom?

Yes, PostHog offers a free tier.

Fathom vs PostHog

Fathom is simple, privacy-focused website analytics. GDPR, CCPA, and PECR compliant, while PostHog is open-source product analytics suite with session replay, feature flags, A/B testing, and surveys. The biggest difference up front: PostHog is free, while Fathom starts at $14/mo. Fathom is built for businesses that want simple analytics without privacy headaches, whereas PostHog targets product teams that need analytics, session replay, and feature flags in one tool.

At a glance

	Fathom	PostHog
Best for	Businesses that want simple analytics without privacy headaches	Product teams that need analytics, session replay, and feature flags in one tool
Starting price	$14/mo	Free
Free tier	—	✓
Open source	—	✓
Free tier available	—	✓
Open source	—	✓
A/B Testing	—	✓
Cookieless	✓	—
EU Isolation	✓	—
Event Tracking	✓	—
Feature Flags	—	✓
Privacy First	✓	—
Product Analytics	—	✓
Session Replay	—	✓
Surveys	—	✓
Uptime Monitoring	✓	—

Fathom

Strengths

Privacy-compliant out of the box
Simple, one-page dashboard
EU isolation option for data residency
Reliable uptime and fast loading

Weaknesses

More expensive than Plausible
Not open source
Limited advanced analytics
No self-hosting option

Try Fathom → Full review

PostHog

Strengths

All-in-one: analytics, session replay, feature flags, A/B tests
Generous free tier (1M events/mo)
Open source and self-hostable
Strong developer experience

Weaknesses

Can be overwhelming — lots of features
Self-hosting requires significant infrastructure
UI has a learning curve
Some features less mature than best-in-class alternatives

Try PostHog → Full review

The bottom line

Pricing: PostHog is completely free, which makes it the obvious pick if budget is the top concern. Fathom starts at $14/mo. That cost buys you a more polished or feature-rich experience, so it comes down to whether the extras justify the spend.

Feature gaps: Fathom offers Cookieless, EU Isolation and Event Tracking that PostHog lacks. PostHog brings A/B Testing, Feature Flags and Product Analytics that Fathom does not have.

Team fit: Fathom is geared toward individual users and small setups, while PostHog is aimed at any size teams. Pick the one that matches where your team is today and where it is headed — migrating tools later is always painful.

Open source: PostHog is open source, meaning you can self-host, audit the code, and avoid vendor lock-in. Fathom is proprietary — you are trusting the vendor with your data and uptime.

Where each tool shines: Fathom's biggest strengths are: privacy-compliant out of the box. simple, one-page dashboard. PostHog's biggest strengths are: all-in-one: analytics, session replay, feature flags, a/b tests. generous free tier (1m events/mo).

Watch out for: With Fathom, users commonly note that more expensive than plausible. With PostHog, the main complaint is that can be overwhelming — lots of features.

Choose Fathom if...

Your profile matches its sweet spot: businesses that want simple analytics without privacy headaches
You specifically need Cookieless and EU Isolation
You care about simple, one-page dashboard
Your team size fits the individuals profile Fathom is designed for

Choose PostHog if...

You need a tool built for product teams that need analytics, session replay, and feature flags in one tool
Budget is a hard constraint — PostHog is free, Fathom is not
You need self-hosting, data sovereignty, or the ability to audit source code
You specifically need A/B Testing and Feature Flags
You care about generous free tier (1m events/mo)