Resource Hints: preconnect

91.15

Gives a hint to the browser to begin the connection handshake (DNS, TCP, TLS) in the background to improve performance. This is indicated using `<link rel="preconnect" href="https://example-domain.com/">`

Further reading:

1. Can I use page for: Resource Hints: preconnect
2. Eliminating Roundtrips with Preconnect