FAQ for the CRUC related to removing Instance Names from URLs

What does the new URL format critical update (CRUC) do?

It changes the URL format used for Visualforce pages in orgs with MyDomain deployed. For example:
 

• Old URL format: https://<MyDomain>--c.<instance>.visual.force.com/apex/<pagename>
• New URL format: https://<MyDomain>--c.visualforce.com/apex/<pagename>

• Old URL format: https://<MyDomain>--<PackageNamespace>.<instance>.visual.force.com/apex/<pagename>
• New URL format: https://<MyDomain>--<PackageNamespace>.visualforce.com/apex/<pagename>

Why is Salesforce making this change?

We’re doing this to simplify the hostnames used in Visualforce URLs as well as eliminate the need to change them during instance refreshes and org migrations.
 

When will the new URL format be enforced?

Starting with the Summer '20 release, all orgs with MyDomain deployed will use the new URL format for Visualforce. Orgs can opt in early by activating the CRUC setting.

We recommend that you enable this critical update in a sandbox first to test it, and make the necessary adjustments before the change goes live.
 

What happens to links I’ve saved, or see in email?

Links using the older format that you’ve saved or have in emails will redirect to the new URL format when they’re accessed.
 

Will the new URL format break my customization?

Yes, that is possible. If you have customization that parse the hostnames within visual.force.com URLs, those customization could break. For example, Visualforce page controllers or client-side JavaScript functions that parse a URL may break or behave differently after this change, especially logic that relies on window.location, if they are making assumptions using the Old URL's hostname format. An example is logic that extracts the MyDomain name from a visual.force.com hostname so that a my.salesforce.com URL can be constructed.

NOTE: Links using the older format that you’ve saved or have in emails will redirect to the new URL format when they’re accessed.
 

How do I enable the new URL format?

In Setup, type Critical into the Quick Find box, then click Critical Updates. Find "Remove Instance Names From URLs for Visualforce, Community Builder, Site.com Studio, and Content Files", and click Activate.
 

Can I disable the new URL format?

You can--by deactivating the CRUC--but we don’t recommend it. If the CRUC is deactivated, the org goes back to using the instance-specific hostnames for Visualforce, Documentforce/Content, Site.com Studio, and Community Builder.

You can only deactivate and reactivate the CRUC setting until the Summer '20 release. After the change goes live with that release, you will no longer have access to the CRUC setting.


Does Remote Site settings need to be updated as this Critical Update is enabled?

No, Remote site settings don't need to be updated as a result of activating or deactivating that critical update. That said, it's best to have the remote site setting use the organization's My Domain name, the one that ends with my.salesforce.com, cloudforce.com, or database.com -- instead of na32 (instance-specific) hostnames.