PostHog error tracking for Web (JavaScript)

Reference files

• references/web.md

  - Web error tracking installation - docs

• references/fingerprints.md

  - Fingerprints - docs

• references/alerts.md

  - Send error tracking alerts - docs

• references/monitoring.md

  - Monitor and search issues - docs

• references/assigning-issues.md

  - Assign issues to teammates - docs

• references/upload-source-maps.md

  - Upload source maps - docs

Key principles

• Environment variables: Always use environment variables for PostHog keys and host URLs. Never hardcode them.
• Minimal changes: Add error tracking alongside existing error handling. Don't replace or restructure existing error handling code.
• Autocapture first: Enable exception autocapture in the SDK initialization before adding manual captures.
• Source maps: Upload source maps so stack traces resolve to original source code, not minified bundles.
• Manual capture for boundaries: Use

  captureException()

  at error boundaries and catch blocks for errors that don't propagate to the global handler.

Framework guidelines

• Remember that source code is available in the node_modules directory
• Check package.json for type checking or build scripts to validate changes
• posthog-js is the JavaScript SDK package name
• posthog.init() MUST be called before any other PostHog methods (capture, identify, etc.)
• posthog-js is browser-only — do NOT import it in Node.js or server-side contexts (use posthog-node instead)
• Autocapture is ON by default with posthog-js (tracks clicks, form submissions, pageviews). Do NOT disable autocapture unless the user explicitly requests it.
• NEVER send PII in posthog.capture() event properties — no emails, full names, phone numbers, physical addresses, IP addresses, or user-generated content
• PII belongs in posthog.identify() person properties (email, name, role), NOT in capture() event properties
• Call posthog.identify(userId, { email, name, role }) on login AND on page refresh if the user is already logged in
• Call posthog.reset() on logout to unlink future events from the current user
• For SPAs without a framework router, capture pageviews with posthog.capture($pageview) or use the capture_pageview history_change option in init for History API routing