Free · No code changes · 2 minutes

How many ghost users are in your PostHog?

Your PostHog instance is probably counting the same person multiple times across devices and sessions. Paste your API key and find out exactly how many duplicate profiles you have.

Settings → Personal API Keys. Starts with phx_ — not your Project API Key.
How to create the right API key
  1. Go to PostHog → Settings → Personal API Keys
  2. Click "Create personal API key"
  3. Give it a name (e.g. "CrossTrack Audit")
  4. Under Scopes, enable read access for:
    Query Read Person Read Event Definition Read
  5. Click Save and copy the key (starts with phx_)
Your key is sent directly to our API and is never stored. We only read your data to count duplicates.
Settings → Project → Project ID
Or enter your self-hosted URL below

Analyzing your PostHog data

This usually takes 30-60 seconds depending on your data volume.

Connecting to PostHog...
Your API key is sent directly to our audit API and is never stored. We only read your event data to count duplicates — nothing is modified in your PostHog instance.

How does the audit work?

1

Pull events

We read your events via PostHog's API using your key

2

Resolve identities

CrossTrack runs identity resolution on your real data

3

Compare

We show you how many profiles are actually duplicates

Your Audit Results

Here's what CrossTrack found in your PostHog data.

Duplicate Clusters

Each cluster below shows PostHog person records that should be one person.

This is just what we can see without being in your data pipeline

Your app and website are creating separate identities for the same users. Install CrossTrack's open-source SDK to stitch them together — including in-app browsers, cross-device sessions, and anonymous-to-known transitions.

Set Up Identity Stitching

3.2 KB web SDK, zero dependencies. Open source on GitHub.