Content Security Policy Report-Only mode explained
Report-Only mode lets teams test Content Security Policy without blocking traffic. It is the safest path to collect real production feedback before moving to enforcement.
Report-Only is the easiest way to reduce rollout risk.
- Collect real violation data before blocking production traffic.
- Tune policy with real user journeys, not assumptions.
- Use grouping and filters to separate noise from critical issues.
- Move to enforcement only when confidence is high.
Step 1: Enable report-only headers
Configure a report endpoint and send policy in Report-Only mode. You get real-world violation data from production users without blocking the page.
Step 2: Analyze noise vs. true issues
Many teams discover that Content Security Policy generates more noise than expected. Extensions, browser quirks, and harmless third-party behavior can flood raw reports.
This is where grouping, filters, exclusions, and historical context matter. Without them, teams stay stuck in log review instead of rollout progress.
Step 3: Tune policy iteratively
Adjust directives in small releases. Keep measuring until report quality is high, noisy violations are under control, and the remaining incidents clearly reflect what still needs attention.
Step 4: Switch to enforcement mode
Move to strict blocking once you trust the policy. Continue monitoring after enforcement to catch regressions from new vendors, releases, marketing changes, or checkout dependencies.
- Use policy revision history to understand what changed.
- Use retained report data to validate that noise is decreasing.
- Use Growth or Business when multiple stakeholders need to act on incidents quickly.
Turn report-only data into a rollout plan
Starter is a strong entry point for teams beginning a Report-Only rollout. Growth is the better fit when you need cross-team operational workflows and faster response.