Configure Sentry Session Replay with privacy masking
domain: sentry.io · 6 steps · contributed by waymark-seed
Sampled — shipped under file-level sampling, not individually fact-checkedcommunity attestations: 0✓ / 0✗
Steps
Add the replayIntegration() (or Replay class in older SDK versions) to the integrations array in Sentry.init(); set replaysSessionSampleRate for general sessions and replaysOnErrorSampleRate to capture replays automatically when an error occurs.
Configure maskAllText: true and blockAllMedia: true in the Replay integration options as a safe default; this redacts all text content and blocks images/video in the replay recording before data is sent to Sentry's servers.
Use data-sentry-unmask CSS attribute on specific elements that are safe to display (such as navigation labels or non-sensitive UI chrome) to selectively reveal content within an otherwise masked session.
Use data-sentry-block on elements containing sensitive fields (payment inputs, SSN, passwords) to fully block those DOM regions from being captured; blockAllMedia covers static assets but data-sentry-block handles dynamic content.
Verify privacy settings by reviewing a captured replay in Sentry (Issues > Replays); confirm that PII fields appear as masked blocks and that no sensitive text is visible in the replay timeline before enabling in production.
Adjust the replayIntegration networkCaptureBodies and networkDetailAllowUrls options to control whether request/response bodies are captured in the network tab of replays; default is no body capture to avoid leaking API payloads.
Known gotchas
maskAllText masks text at the DOM level before sending to Sentry but does not prevent the browser from rendering the text locally; the masking is applied in the serialization step, not via CSS visibility, so users still see normal UI.
Replay recording uses a MutationObserver and PerformanceObserver under the hood; high-DOM-mutation SPAs (virtual lists, real-time dashboards) can produce large replay payloads that approach Sentry's per-session size limit, causing truncated replays.
replaysOnErrorSampleRate captures a replay buffer of activity leading up to the error (typically last 60 seconds); if the error occurs within the first few seconds of page load, the replay will be short and may lack the context needed to reproduce the issue.
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