Use preconnect for critical third-party origins

Preconnecting to essential origins can shave hundreds of milliseconds off the critical path by handling connection overhead ahead of time.

Quick Reference

• Establish early connections to important third-party domains (e.g., fonts, APIs)
• Reduce latency by performing DNS lookup, TCP handshake, and TLS negotiation early
• Avoid overusing preconnect; limit to 2-4 most critical origins

Check

Review the page's head for preconnect hints and identify any missing or unnecessary connections to third-party domains.

Fix

Add <link rel="preconnect"> for critical third-party origins and remove it for non-essential or underutilized domains.

Explain