Zenith vs PostHog
A small, cookieless tool where PostHog is a platform
PostHog is the most open of the product analytics tools and the fairest comparison here — open source, genuinely self-hostable, and generous with its free tier. It is also a platform: replay, flags, experiments, surveys, a data warehouse. Zenith is a single-purpose tool, and that is the choice on offer.
Zenith vs PostHog, feature by feature
Including the rows Zenith loses. Where PostHog has something behind a paid tier or a plugin, the table says so rather than pretending it is missing.
| Feature | Zenith | PostHog |
|---|---|---|
| Privacy & compliance | ||
| Cookie-free tracking | Yes | Configurable |
| No cookie banner required | Yes | Depends on config |
| GDPR compliant by default | Yes | Requires configuration |
| No personal data collected | Yes | No |
| You own the raw data | Yes | Self-hosted only |
| Open source | MIT | MIT core |
| Self-hosting | Yes | Hobby deploys |
| Analytics features | ||
| Real-time dashboard | Yes | Yes |
| Visitors, pageviews, sessions | Yes | Yes |
| Bounce rate & visit duration | Yes | Yes |
| Custom events | Yes | Yes |
| UTM & campaign tracking | Yes | Yes |
| Funnel analysis | No | Yes |
| Cohort analysis | No | Yes |
| Session replay | No | Yes |
| Heatmaps | No | Yes |
| A/B testing | No | Yes |
| Feature flags | No | Yes |
| Agency & client work | ||
| Unlimited sites per deploy | Yes | Per project |
| Cost per extra client site | Nothing | Counts toward your events |
| Dashboard on the client's own domain | Yes | No |
| Client never sees a third-party tool | Yes | No |
| Automatic monthly client emails | Yes | Subscriptions |
| Per-client logins | Yes | Team seats |
| SEO | ||
| Built-in SEO audits | Yes | No |
| Core Web Vitals from a real render | Yes | No |
| SEO report emails | Yes | No |
| Setup & usability | ||
| Install | Script tag or npm | Script or SDK |
| Learning curve | Minutes | Days |
| Tracking script size | ~1 KB | ~50 KB |
| API access | Yes | Yes |
| Unsampled data | Yes | Plan dependent |
| Hosting & pricing | ||
| Hosting | Self-hosted | Cloud or self-hosted |
| Pricing model | Free, open source | Usage-based per product |
| Price scales with | Nothing | Events, replays, flags |
| Every feature included | Yes | Priced per product |
Platform versus tool
PostHog bundles product analytics, session replay, feature flags, experiments, surveys and more, and if you want those under one roof it is hard to beat. Zenith does web analytics and SEO for many sites, and stops. If you need flags and experiments, no amount of Zenith adds up to PostHog — the comparison is about whether you want the platform at all.
What self-hosting actually costs
PostHog's own guidance steers most people to their cloud, because a self-hosted deployment at scale is a serious operational commitment. Zenith is designed to be self-hosted by one developer: docker compose up, two Go services, two embedded database files, and no cluster. That is only an advantage if self-hosting is what you wanted.
Cookies and consent
PostHog identifies users, which in practice means cookies and a consent path in the EU and UK. Zenith derives a daily-rotating hash server-side and stores no identifier, so no banner is needed. For a client's brochure site — where a consent dialogue is a conversion cost and a conversation you would rather not have — that difference matters more than feature count.
The client-facing half
Zenith mounts the client's dashboard inside their own application, so their numbers appear on their own domain with no third-party branding, and it emails them a monthly summary of traffic and SEO. PostHog is built for the team building the product, not for handing a report to the person who paid for the site.
Own your clients’ analytics.
One deploy, every site you build, no consent banner and no per-site cost. It is MIT licensed and it runs on one server.