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1xx · Informational

103 Early Hints

An interim response that lets the browser start fetching critical assets before the final page arrives.

What it means

HTTP 103 Early Hints is sent before the final response while the server is still putting the page together. It carries Link headers that point at resources the page will need — a stylesheet, a key script, a font — so the browser can begin preloading them early instead of waiting for the full HTML. The real response follows once it is ready.

When it happens

It happens on servers and CDNs configured to send early hints for performance, where there is a measurable gap between the request arriving and the final HTML being generated. The browser uses that gap to warm up the connections and downloads it already knows it will need.

How to fix it

  • Nothing to fix — 103 is a performance optimisation, not an error.
  • List only genuinely critical resources in the Link headers; hinting too much can waste bandwidth.
  • Confirm your CDN and origin both support early hints before enabling it, since older intermediaries may mishandle it.

SEO impact

Indirectly positive. Early hints can improve load speed and Core Web Vitals, and faster pages tend to fare better in search. The status itself is never indexed.

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