Use DNS prefetch

Implement DNS prefetch to help reduce page load times with different applications and services.

Understanding DNS prefetch

Browsers use DNS prefetch to automatically resolve domain names linked on a Web page to their corresponding IP addresses. The prefetch process starts when your browser loads a web page. As an example, assume that your page contains a selectable link to When a browser loads this page, it uses the DNS system to look up the linked domain name and resolve it to a corresponding numeric IP address. DNS prefetch helps improve page performance because the domain name is already resolved to an IP address before a site visitor clicks that link or button. The DNS prefetch process is transparent to the users.

DNS prefetch and Adobe Experience Cloud applications

DNS prefetch works automatically with static, embedded links on a page. This also means automatic DNS prefetch doesn’t work with different Experience Cloud applications and services because:

  • Each Experience Cloud application or service generates DNS calls dynamically as the page loads.
  • The browser can’t resolve domain names to IP address before these calls are made.

However, you can manually implement DNS prefetch with your Experience Cloud applications. You do this by adding the HTML <dns-prefetch> tag to the <head> section of your page code as shown below. When implemented properly, DNS prefetch can help save a few milliseconds of page load time.

DNS prefetch code samples

The following examples show you how to make DNS prefetch calls to different Experience Cloud applications and services. Some prefetch calls require your Adobe Organization ID or tracking server information. In these examples, the code in italics represents a variable placeholder. You would replace that code with your own Adobe partner ID, customer code, or tracking server information, and so on.

  • Analytics: <link rel="dns-prefetch" href="//">.

    Add a separate tag for each DNS name if you use non-secure and secure tracking servers.

  • Audience Manager: <link rel="dns-prefetch" href="//">

  • Experience Cloud ID Service: <link rel="dns-prefetch" href="//">

  • Advertising Cloud:

    • <link rel="dns-prefetch" href="//">
    • <link rel="dns-prefetch" href="//">
  • Target: <link rel="dns-prefetch" href="//">