1xx Informational
HTTP 103 Early Hints
An interim response that carries Link headers, such as preload and preconnect, before the final response. The browser can start fetching style sheets and fonts or connecting to other origins while the server is still building the page, which can make the page appear sooner.
Defined in RFC 8297, section 2(opens in a new tab)
//_01 Uptime checks
Is 103 up or down for a monitor?
Uptimecheck HTTP monitor
Default settings
Not judged on its own. It is an interim response; the check waits for the final status that follows, and that one decides.
Is it down? checker
Free, at /is-it-down/
Not judged on its own. It is an interim response; the check waits for the final status that follows, and that one decides.
//_02 Causes and fixes
Why you see 103 and what to do
Typical causes
- The server or a CDN in front of it is set up to send early hints for the page.
If you run the site
- Only hint at resources the page really uses; wasted preloads compete with what the page needs.
- Browsers act on early hints for page navigations, and Chrome only over HTTP/2 and HTTP/3.
If you’re a visitor
- Nothing to do: the page itself arrives with the final status, usually 200.
Know the moment your site stops answering as it should
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Questions
What does HTTP 103 mean?
An interim response that carries Link headers, such as preload and preconnect, before the final response. The browser can start fetching style sheets and fonts or connecting to other origins while the server is still building the page, which can make the page appear sooner.
Does an uptime monitor count 103 as down?
Not judged on its own. It is an interim response; the check waits for the final status that follows, and that one decides.
Downtime is obsolete.
Set up your first monitor in under a minute, or look around the live demo first.
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