Salesforce Sandbox Preview Instructions

Winter '27 is coming with lots of new features. Use your sandbox to get early access to new features and test your configurations before the production upgrade. 

The sandbox preview window for Winter '27 begins August 28, 2026. You must have an active sandbox on a preview instance by August 27, 2026 (the day before sandbox preview) to take advantage of the preview.

Here’s how... First, decide whether you want to:

• Keep one or more of your sandboxes on the current Summer ’26 release version, or,

• Try the next major release, Winter '27 version, in your sandbox(es). 

After you decide: 

• Check if the Release Type of the sandbox is preview (upgrade) or non-preview (no upgrade), and

• Determine if you need to refresh and when, based on the cutoff date of August 27, 2026.

Usually, no action is required because your sandbox is already on a preview instance. 

How Does Sandbox Preview Work?

The sandbox preview is a 6-week window ahead of a major Salesforce release when all preview sandboxes are upgraded to the next major Salesforce release. It’s your first chance to test your configurations on the new release.

Sandboxes are updated in groups based on the instance where they’re located. All sandboxes on a preview instance get upgraded together, and all sandboxes on non-preview instances remain on the current release. The only way to change the upgrade status of a sandbox is to move it to another instance by refreshing it. If you want to move it to a preview instance, you must do so before the cutoff date.

To create a sandbox on a Winter '27 preview instance, you must create or refresh the sandbox in advance of 6:00 PM PT on August 27, 2026 (01:00 UTC on August 28, 2026). If your sandbox request is complete in time, we upgrade it to Winter '27.

To create a sandbox on a Summer '26 non-preview instance, you have two options:

1. Select the Request Non-Preview option when you create or refresh a sandbox before 6:00 PM PT on August 27, 2026 (01:00 UTC on August 28, 2026). This non-preview request feature is enabled through an org permission. To get this permission, contact Salesforce Customer Support. After you receive the permission, the Request Non-Preview option will be available to all sandboxes created for a given org during preview request windows going forward. 
    

2. Create or refresh a sandbox as normal after 6:00 PM PT on August 27, 2026 (1:00 UTC on August 28, 2026). 

For the Winter '27 Release, we upgrade the preview instances to Winter '27 on August 28 and August 29, 2026, and non-preview instances to Winter '27 on October 9 and October 10, 2026.

The following timeline shows the following key dates for creating a sandbox on a preview or non-preview instance:

• Non-Preview Opt-In: This is the period of time in which you can create a sandbox on a preview instance by default, or request a non-preview instance.

• Sandbox Preview Window: This is the period of time in which orgs on preview instances will be exposed to the new release. Production and non-preview instances are upgraded to the new release around 6 weeks after the start of the sandbox preview window.

Follow the basic process below if you want your sandbox to participate in the Winter '27 preview. 

1. Find your sandbox details.
In production, from Setup, in the Quick Find box, enter Sandbox, and then select Sandbox. Use the Release Type column to determine if your sandbox is on a preview or non-preview instance.

You can also use the Sandbox Preview Guide to determine if each of your sandboxes is on a preview or non-preview instance. Enter your sandbox instance name(s). The guide tells you if it’s preview or non-preview and what to do to either move to the next release (Winter '27) or stay on the current release (Summer '26). You can also check multiple sandboxes and view the full list of preview and non-preview instances.

2. Understand the cutoff date.

Every release, we give you a cutoff date for sandbox refresh completions, and usually, it’s the day before the preview starts. For Winter '27, the cutoff date is August 27, 2026. Any sandbox created after the cutoff isn’t a preview sandbox. If you have a sandbox on a preview instance and refresh it after the cutoff, your sandbox is routed to a non-preview instance and reverts to Summer '26.