Not working: DNS Pre-fetch for External Domains

DNS Pre-fetch rules are correctly rendered on your site. However, there are more that aren’t added there. I think it’s the way the tool reports issues – not only the ones that are not prefetched put pretty much all external domains you have.

Hello,

Could you please check if DNS pre-fetch is working on my site (electricvehicleweb (dot) in), we have included –

//google-analytics.com

//www.youtube-nocookie.com

//feeds.feedburner.com

//www.instagram.com

//pinterest.com

//twitter.com

//www.facebook.com

//youtube.com

We primarily use Facebook embed, Twitter embed, Youtube embed (youtube-nocookie.com embed) on our blog posts and Google Analytics.

I did not notice any changes in the loading, hence could you please check if this is working, and if there anything that we are doing incorrectly?

I can see the proper lines added to your site:

<link rel=”dns-prefetch” href=”//youtube.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//facebook.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//twitter.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//pinterest.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//instagram.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//feeds.feedburner.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//youtube-nocookie.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//feedburner.google.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//google-analytics.com” data-set-by=”SG Optimizer”/>

This is not an optimization that you will notice right away since you most probably already have that hostname resolved and cached locally.

Hello,

I’m still talking about the domain i sent you in my first message.

I did setup the pre-dnsfetch to the 14 external domains (listed below). I don’t get the impression that it is working properly because when running GTmetrix, or Lighthouse Tests, i see that it is only working on 2 domains. Also when i look at the source code with Chrome Developer tools, i see the same thing. According to me, it’s only working for (but not even set by SG Optimizer):
<link rel=’dns-prefetch’ href=’//fonts.googleapis.com’ />
<link rel=”dns-prefetch” href=”https://cdn.statically.io/&#8221; >

What could cause this? Am I right with my conclusion?
Could a command line in .htaccess or a particular option in my Ninja Firewall interact with that?

List of domains i entered in SG Optimizer (pre-dnsfetch feature):
//c9.radioboss.fm
//googletagmanager.com
//youtube.com
//script.hotjar.com
//s.ytimg.com
//maps.gstatic.com
//in.hotjar.com
//font.gstatic.com
//app.continual.ly
//connect.facebook.net
//maps.googleapis.com
//cdn-app.continual.ly
//cdn.statically.io
//fonts.googleapis.com

• This reply was modified 4 years, 3 months ago by jlebouch76.

Open the site html source and see the lines added for those domains.

I did exactly that and i found that only 2 domains were dns-prefetch. I mentioned those is my message few minutes ago.

Which domain are you talking about? You have specified https://happynew.radiojyoti.com in your first ticket and in that domain all the lines are properly rendered:

<!– END OF WP_HEAD() –>
<link rel=”dns-prefetch” href=”//fonts.googleapis.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//cdn.statically.io” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//cdn-app.continual.ly” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//maps.googleapis.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//connect.facebook.net” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//script.hotjar.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//app.continual.ly” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//font.gstatic.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//in.hotjar.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//maps.gstatic.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//s.ytimg.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//script.hotjar.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//youtube.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//googletagmanager.com” data-set-by=”SG Optimizer”/>
<link rel=”dns-prefetch” href=”//c9.radioboss.fm” data-set-by=”SG Optimizer”/>

Yes it is working…. but I can’t figure out why i can see those 14 domains when i log out from the backend. Whereas when i’m logged in as Admin, i only see 2 domains listed in the source code.

Because it goes through the optimization parser which does not work for admins / logged in users. Open an incognito tab and you will see all the domains.

oh that’s why. i always do my development work with Incognito tab, so that’s why i didn’t see the difference.

Does this mean that if i want to check all effects of SG optimizer, i need to be logged out completely?
What are the features that would not work for Admin or logged in users?