medium

Too Many Redirects (HSTS)

HSTS configuration creating a redirect loop between HTTP and HTTPS.

Common Causes

  1. 1Load balancer terminates SSL but backend redirects to HTTPS again
  2. 2Cloudflare Flexible SSL with server-side redirect

How to Fix

Trust proxy headers

if ($http_x_forwarded_proto = 'http') {
    return 301 https://$host$request_uri;
}

Only redirect when the original request was HTTP.

How ObserveOne Helps

A redirect loop makes the site unreachable even though the server is up. An ObserveOne uptime check fails on the loop, so a redirect change that goes wrong pages you the moment it ships.

Start Monitoring Free

Related Errors

ERR_SSL_PROTOCOL_ERROR

The browser cannot establish a secure SSL/TLS connection because the server and browser cannot agree on a protocol version or cipher suite.

Mixed Content: Insecure resource requested

HTTPS page loading resources over HTTP. Modern browsers block mixed content.

ERR_SSL_VERSION_OR_CIPHER_MISMATCH

Server and browser cannot agree on SSL/TLS protocol version or cipher suite.

NET::ERR_CERT_AUTHORITY_INVALID

SSL certificate is not signed by a trusted Certificate Authority.

NET::ERR_CERT_DATE_INVALID

SSL certificate has expired or is not yet valid.