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Performance

When to use preconnect resource hints

Each new origin costs a DNS lookup, a TCP handshake and a TLS negotiation before a single byte arrives — often 200–500 ms on mobile. A preconnect starts that work early. Only hint at origins you actually use; speculative preconnects waste connections.

What 13x checks

This is rule performance.preconnect in the public registry: Third-party origins are preconnected. It runs on every audit, against the pages we actually fetched, and its result is derived from the response rather than estimated.

Surface
Performance
Score weight
3 of the readiness score
Scope
Reported as skipped when the page renders only with JavaScript
Applies
Only where the market or the page shape makes it relevant

Registry version 2026-07-30. Every rule is published, and the audit is deterministic — the same page produces the same finding every time.

The fix

The same text the audit hands you when this check fails on your own site.

Third-party origins used without a connection hint: .

html code
<link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
<link rel="dns-prefetch" href="https://analytics.example.com" />

Each new origin costs a DNS lookup, a TCP handshake and a TLS negotiation before a single byte arrives — often 200–500 ms on mobile. preconnect starts that work as soon as the HTML is parsed.

Two constraints: only hint at origins the page genuinely uses, because each one holds open a connection, and keep it to three or four. crossorigin is required for fonts or the connection is not reused.

If the origin is a font CDN, self-hosting removes the round trip entirely and is the better fix.

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