HSTS header missing: Enforce HTTPS consistently
HSTS protects HTTPS pages from downgrade and protocol issues.
HSTS protects HTTPS pages from downgrade and protocol issues The error should never be assessed in isolation. What matters is which URL group is affected and whether it creates a crawling, indexing, snippet, performance or quality problem.
HSTS roll out only after reliable HTTPS
HSTS informs the browser that a website should be used via HTTPS in the future. Before the rule is set, certificate and encrypted accessibility must work reliably. With includeSubDomains, the specification also applies to subdomains that may be operated differently.
Example: Recognizing the Result
Illustrative example: The website works via HTTPS, but does not provide an HSTS default. Before this is activated, all affected hosts must be reliably reachable via HTTPS.
Limit cause and implement correction
Invent affected hosts and control the header on an HTTPS response. Start with a deliberately chosen validity period and check the effects. A long default cannot be circumvented for already informed browsers by a simple HTTP exception. HSTS is a security decision, not a direct proof of better rankings.
What makes you recognize a suitable correction
Check certificates, forwarding and, if applicable, subdomains. Configure HSTS carefully and control effects on previous HTTP accesses.
Classification and boundaries
When is this indication not a clear error?
includeSubDomains and preload do not use without full host verification. The lack of HSTS is not evidence of a concrete ranking loss.
Further documentation
HSTS header missing after CMS and cause
Many audit messages can be resolved faster if they are grouped by system, page type and technical cause. CMS indentations are only linked where HSTS header lacks a clearly own cause or fixed route in the respective system.
For this error, there is currently no own CMS deepening, because the correction is usually not sufficiently system-specific. Take advantage of the general causes and checks on this page.
Frequent causes of this error
Related SEO Errors
Appropriate Seitenreport checks
This error should not be checked in isolation. The following tools and clusters help to narrow down the cause faster and to cleanly prioritize the affected URL groups.