Pairing dns-prefetch and preconnect

[jquinc30]

MDN URL

https://developer.mozilla.org/en-US/docs/Web/Performance/dns-prefetch

What specific section or headline is this issue about?

#best_practices

What information was incorrect, unhelpful, or incomplete?

preconnect will perform the dns lookup but also establishes a connection to a server where dns-prefetch will only do the first part.

The best practice encourage to use both:

The logic behind pairing these hints is because support for dns-prefetch is better than support for preconnect.

What did you expect to see?

As the support for preconnect seems to be pretty ok now and httpS is the standard (where the potential gain of preconnect is at the maximum), I think that pairing is no more useful.
I was expected to be encouraged to only use preconnect

Do you have any supporting links, references, or citations?

https://caniuse.com/link-rel-dns-prefetch

https://caniuse.com/link-rel-preconnect

Do you have anything more you want to share?

No response

MDN metadata

Page report details

• Folder: en-us/web/performance/dns-prefetch
• MDN URL: https://developer.mozilla.org/en-US/docs/Web/Performance/dns-prefetch
• GitHub URL: https://github.com/mdn/content/blob/main/files/en-us/web/performance/dns-prefetch/index.md
• Last commit: e74627e
• Document last modified: 2023-07-04T10:01:14.000Z

[pepelsbey]

Hello! Good catch :) I agree that support is good enough for this hint to become obsolete. However, I would keep this note:

If a page needs to make connections to many third-party domains, preconnecting them all is counterproductive. The preconnect hint is best used for only the most critical connections. For the others, just use <link rel="dns-prefetch"> to save time on the first step — the DNS lookup.

Feel free to file a PR with fixes!