What it means
The server received the request headers and the client may continue sending the body. Informational responses are interim. The client should keep waiting or continue.
Common causes
Large uploads using the Expect: 100-continue header.
How to fix it
Usually handled automatically; nothing to fix.
If you are a visitor
Nothing is wrong. Your browser handles this response automatically.
If you own the site
Nothing to retry. Search engines do not index 1xx responses; they wait for the final status. Run the HTTP status checker to see exactly what your URL returns, and use uptime monitoring to be told when it changes.
Frequently asked questions
What does HTTP 100 mean?
Continue: The server received the request headers and the client may continue sending the body.
Is HTTP 100 an error?
No. Informational responses are interim. The client should keep waiting or continue.
Does HTTP 100 affect SEO?
Search engines do not index 1xx responses; they wait for the final status.
Should I retry after HTTP 100?
Nothing to retry.