Test read-only mode functionality in a sandbox

The Read-Only Application Test Mode is a feature available in a subset of sandbox organizations for simulating the read-only mode functionality that Salesforce uses during maintenance events such as Instance Refreshes and Site Switches.

Turning on the test mode makes all requests for users in the org (as well as all API requests, integrations, batch jobs, etc.) behave in a read-only way (i.e., no data can be saved or updated) until the test mode is turned back off. This feature allows organizations to test their integrations, UI, functionality, or other behavioral testing for Read-Only mode.

Read-Only Application Test Mode feature in sandbox organizations can be enabled by going to "Setup -> Administer -> Data Management -> Read Only Application Test Mode."

If you don't have a Read-Only Application Test Mode available in Setup, contact Support to determine if your sandbox organization is eligible for this feature. At this time, the Read-Only mode is only supported on Hyperforce sandbox instances. Please contact support to assist with setting up a sandbox on the available instance if you need to test with this feature. If you are still on a first party server, sending a copy to a Hyperforce instance may be available subject to approval.