SiteAud!tLint Support

Opportunity Security

Missing HSTS header

Severity
Opportunity
Impact
Low
Effort to fix
Low
Issue code
hsts_missing

Why it matters

Strict-Transport-Security forces browsers to always use HTTPS, preventing downgrade attacks.

How to fix it

Add a Strict-Transport-Security header, for example max-age=31536000; includeSubDomains.

How it affects your score

Finding this issue on any page costs the Security score 0.5 points, plus up to 4 more depending on the share of crawled pages affected. A smaller improvement with a modest effect on its own.

Find the affected URLs

Open Crawl > Issues and pick Missing HSTS header. Each affected URL is listed with its evidence, and Copy URLs or Export URLs hands the list to a developer. The issue also appears in the Action Plan, ranked by impact (low) and effort (low), and in the issues CSV under the code hsts_missing. After fixing, run a new audit and use Compare to confirm the URLs moved to fixed.