Defaults.Exposed › September 2026 census › v10 registry › Referrer-Policy
Referrer-Policy
Methodology v10 · canonical ID referrer-policy · Web Security · scored · census as of September 5, 2026
Controls what address info leaks to other sites when visitors click away.
Definition
| Canonical ID | referrer-policy |
|---|---|
| Category | Web Security |
| Grade impact | Scored, counts toward the grade |
| Pass | The site sends a Referrer-Policy header. |
| Fail | The header is absent. |
| Example (passing) | Referrer-Policy: strict-origin-when-cross-origin |
No-data rule: when this check couldn't be determined for a domain (timeout, SERVFAIL, redacted source) it returns N/A and is excluded from that domain's scoring denominator: "couldn't determine" is never counted as a failure. "Determined absent" is a real fail.
Prevalence across the census
7.91% of graded domains send a Referrer-Policy header (9,952,036 of 125,815,036, as of September 5, 2026).
Census denominator: 316,600,902 graded domains. Aggregates only: never an individual domain's result.
Fix it
Plain-English impact, cost of ignoring it, and step-by-step remediation: defaults.exposed/fix/referrer-policy
Cite this check
Defaults.Exposed, "Referrer-Policy (referrer-policy)", Grading Methodology v10 (census as of September 5, 2026). https://defaults.exposed/v10/methodology/referrer-policy
Permalink: https://defaults.exposed/v10/methodology/referrer-policy ·
All 34 checks: v10 registry ·
Machine-readable: /v10/methodology/checks.json ·
Licence: open data