PostHog Debugger (Unofficial) — Gevorg Glechyan

PostHog Debugger (Unofficial) adds a dedicated PostHog panel to Chrome DevTools for developers validating analytics on their own sites, staging environments, localhost apps, embedded widgets, and self-hosted or reverse-proxied PostHog setups.

General debugging:

• Start with a Config view that shows loaded state, SDK version, destination, capture settings, consent/opt-out state, identity, and visible PostHog instances.
• Inspect live PostHog activity without leaving the page you are debugging.
• Capture PostHog traffic from top-level pages and iframes where Chrome allows extension scripts to run.
• Keep a local session timeline that can be paused, cleared, filtered, and exported.

Events and payloads:

• Decode PostHog requests sent through fetch, XHR, sendBeacon, batch payloads, gzip, base64, form-encoded data, and query-string payloads.
• Review event names, custom properties, PostHog $ properties, $set, $groups, timestamps, API keys, and raw JSON.
• Filter event captures by search text, event kind, issue state, frame source, and request status.
• Export captured sessions as JSON or HAR for local debugging, bug reports, and support handoffs.

Network and delivery:

• See raw PostHog request status, endpoint, size, timing, method, and decoded event matching.
• Spot blocked requests, failed requests, wrong hosts, missing tokens, and non-2xx responses.
• Build privacy-conscious support details without copying cookies or broad browser headers.

Config, identity, flags, and replay:

• Read the active window.posthog snapshot for SDK configuration, distinct ID, device ID, session ID, replay URL, and loaded feature flags.
• Inspect feature flag values, payloads, evaluation evidence, and local override state.
• Follow identify, alias, group, and reset activity in a dedicated Identity view.
• Distinguish cookied, cookieless memory, and server cookieless $posthog_cookieless identity modes.
• Surface session replay diagnostics from captured events, including replay status, sampling, trigger, and recorder evidence when available.

Validation and privacy checks:

• Flag missing event names, missing distinct IDs, missing API keys, failed requests, duplicate fires, reserved prefixes, large payloads, clock skew, and inconsistent naming.
• Warn on likely PII in event properties, nested objects, profile properties, group properties, phone numbers, emails, card-like values, passwords, and token-like values.
• Preview likely PostHog autocapture output locally so developers can inspect target elements and property shape without sending a real autocapture event.

Privacy and data handling:

PostHog Debugger displays inspected analytics data locally in the DevTools panel. It does not send inspected event payloads, browsing data, or SDK state to the developer or to any external service, and it does not sell, share, or use inspected data for advertising or profiling. The extension is not affiliated with, endorsed by, or sponsored by PostHog.