103Early Hints
A preview of headers sent before the real response, so the browser can start fetching stylesheets and scripts sooner.
Browse all HTTP status codesWhen you see it
A server that knows a page will need a particular stylesheet can send 103 with a Link header immediately, while it is still assembling the actual page. The browser starts downloading that stylesheet during time it would otherwise spend waiting.
It is a performance feature rather than an error, and it is invisible to users. Support is good in modern browsers and several large content networks send it automatically.
Look up another one
Open
Type a code, a partial code like 40, or any word from a name or description. Everything runs in your browser.
Filter
Copy format
Status codes
69 of 69 codes. Click a row to copy it.
1xx Informational (4)
2xx Success (10)
3xx Redirection (8)
4xx Client errors (31)
5xx Server errors (16)