HSTS

web security policy

01 Definition

HSTS meaning: A header that forces browsers to always connect to a site over secure HTTPS.

HSTS is HTTP Strict Transport Security, a response header that tells browsers to only connect to a site using HTTPS. Once set, the browser refuses insecure HTTP connections for that domain for a defined time. It helps block downgrade attacks and stops users from reaching an insecure version.

Also called

HTTP Strict Transport Security

Why it matters

How HSTS fits the work

It hardens a site by forcing secure connections, which reduces the risk of attackers downgrading users to insecure HTTP or intercepting early requests.

In context

The security team added an HSTS header with a one-year duration so browsers would always load the banking portal over HTTPS.

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Practical note

Test carefully before enabling long durations, because a browser will honor HSTS for the set period. If HTTPS later breaks, users can be locked out until it is repaired.