SigInspector - Statsig, Mixpanel, Amplitude & PostHog Inspector

Inspect Statsig, Mixpanel, Amplitude and PostHog events, feature flags and experiment exposures directly in Chrome DevTools.

SigInspector adds a dedicated panel to Chrome DevTools that intercepts and displays Statsig, Mixpanel, Amplitude and PostHog JavaScript SDK calls in real time, in a clean, filterable interface. What you can see: - 📋 Events from logEvent, track and capture calls, with their properties - 🚦 Gate and feature flag evaluations, with values, variants and reasons - 🧪 Experiment and layer exposures - 👤 Identify calls and profile updates - ⚙️ SDK initialization and flag responses Supported SDKs: - Statsig: events, gate checks, experiment and layer exposures, initialize - Mixpanel: events, profile and group updates, feature flags - Amplitude: events, identify, revenue, Amplitude Experiment variants - PostHog: events, autocapture, identify, feature flags Mixpanel, Amplitude and PostHog are also captured when sent through your own domain (reverse proxy). All activity appears instantly as it happens. See every SDK in one timeline, or pick one from the source menu. ⚡ Why SigInspector? Debugging analytics instrumentation normally means parsing raw network requests, decoding payloads by hand, and guessing which variant or flag a user received. SigInspector eliminates that friction with a structured, readable view of SDK activity. - ✅ Confirm events are firing with the right properties - 🎯 Verify which gate, flag or experiment variant a user saw - 🔎 Identify missing exposures, or events sent to one tool but not another - 🐛 Debug instrumentation issues in seconds What's in v1.1.0 🆕 - 🔌 Mixpanel, Amplitude and PostHog support, alongside Statsig - 🔀 Source menu: all SDKs in one timeline, or one at a time - 🏷️ One set of filters for every source: Events, Auto, Identity, Flags - 📐 Control whether detail panel docks right or bottom - 📤 Export the current view or everything as JSON - 🐛 Fixed events going missing after switching filters What's in v1.0.2 - 📝 Added support for user object visibility that was previously hidden from panel - 🐛 Fixed bug where copy JSON would copy payload from multiple events What's in v1.0.1 - UX improvements and bug fixes - Opt in event memory to preserve events across page refreshes - Improved capture now works when content blockers prevent requests from reaching Statsig servers Getting started: - Install the extension - Open Chrome DevTools (⌘⌥I / F12) - Click the SigInspector tab No configuration. No Statsig, Mixpanel, Amplitude or PostHog account required. Privacy: SigInspector runs entirely in your browser. It only reads traffic from these four SDKs, and it does not collect, store, or transmit any data externally.