ERR_SSL_OBSOLETE_VERSION: The site uses an obsolete TLS version
Also searched as: obsolete TLS · TLS 1.0 warning · not secure obsolete connection
Is ERR_SSL_OBSOLETE_VERSION happening on your domain?
The SSL check reports the negotiated protocol version, confirming whether the fix actually took effect at the edge that answers.
Free, no signup. Runs from outside your network, which is the only way to tell a server fault from a local one.
Short answer
A warning rather than a hard failure: the connection succeeded but negotiated TLS 1.0 or 1.1, which browsers flag as obsolete and will eventually refuse outright.
What ERR_SSL_OBSOLETE_VERSION means
Browsers surface this to give operators warning before the protocol is removed. The page still loads today. It will stop loading when the browser drops support, usually without further notice.
Causes and fixes, most likely first
The origin's TLS configuration has not been updated since before TLS 1.2 became the baseline.
Enable TLS 1.2 and 1.3 and disable 1.0/1.1. Confirm with an external check that 1.2 is actually being negotiated afterwards.
A load balancer or WAF in front of the origin is terminating TLS with old settings.
Update the TLS policy on the load balancer — the origin's own configuration is irrelevant when something in front terminates first.
How to stop it happening again
- •Monitor the negotiated TLS version continuously, not just at deploy time.
Frequently asked questions
Is ERR_SSL_OBSOLETE_VERSION blocking my visitors?
Not yet — it is a warning. It becomes a hard failure when the browser removes the protocol, so treat it as a deadline rather than an outage.