S
SaaS Decision
⚡ Head-to-Head Deterministic Intelligence

PostHog vs Fathom Analytics

Comprehensive deterministic comparison evaluating decision scores, pricing models, replacement difficulty, and open-source alternatives for 2026.

Product Analytics

PostHog

Starting PriceFree

Open-source product analytics suite with session replay, feature flags, and A/B testing.

Verdict:SELF HOST
Full PostHog Review ↗
Analytics & Reporting

Fathom Analytics

Starting Price$15/mo

Simple, privacy-first website analytics alternative to Google Analytics.

Deterministic Decision Engine

Side-by-Side Decision Scores Matrix

Evaluated using pure deterministic algorithm scoring across retention, migration savings, self-hosting viability, and build complexity.

Evaluation MetricPostHogFathom Analytics
Primary VerdictSELF HOSTAUTOMATE
KEEP Score (Retention Value)
68/100
48/100
SWITCH Score (Migration Savings)
74/100
88/100
SELF-HOST Score (OSS Viability)
79/100
85/100
AUTOMATE Score (Workflow Parity)
78/100
100/100
BUILD Score (Custom In-House Feasibility)
15/100
35/100
Engine Confidence62%84%
Build Complexity (1 - 5)4 / 52 / 5
API & Webhook Availability5 / 54 / 5
Vendor Lock-in Risk2 / 51 / 5
Data Portability Score5 / 55 / 5
Cost Structure Analysis

Verified Pricing Tiers Comparison

PostHog Pricing Tiers

Freemonthly billing
Free
Scalemonthly billing
$45/mo

Fathom Analytics Pricing Tiers

Startermonthly billing
$15/mo
Zero License Fees

Self-Hostable Open Source Options

PostHog Open-Source Options

PostHog Self-Hosted23.1k★

Open-source product analytics backend.

Mixpanel1.2k★

Commercial product analytics platform.

Fathom Analytics Open-Source Options

Umami21.4k★

Open-source web analytics.

Ackee4.2k★

Node.js privacy-focused analytics.

Head-to-Head FAQs

Frequently Asked Questions: PostHog vs Fathom Analytics

Which tool is easier to migrate or build custom?

PostHog has a build complexity of 4/5 and API availability of 5/5. Fathom Analytics has a build complexity of 2/5 and API availability of 4/5.

Should I choose PostHog or Fathom Analytics?

If you prioritize retention value and deep integrations, PostHog leads with a KEEP score of 68/100. If you are looking to switch or optimize costs, review their secondary verdicts and open-source alternatives above.