Because users do not enter credentials when using unauthenticated access, it is possible for RDS hosts to become overwhelmed by requests for published applications. Login deceleration alleviates this. You can adjust the level of deceleration. You can also block clients that do not support deceleration.


  • Verify that you have enabled unauthenticated access for users.
  • Verify that you have Horizon Client version 4.9 or later.


  1. In Horizon Console, select Settings > Servers.
  2. Click the Connection Servers tab.
  3. Select a Connection Server and click Edit.
  4. Click the Authentication tab.
  5. From the Login Deceleration Level drop-down menu, select a deceleration level for unauthenticated access logins.
    Option Description
    Low Sets a low deceleration level for unauthenticated access logins. For Web browsers such as Microsoft Internet Explorer and Microsoft Edge, the recommendation is to set the low deceleration level.
    Medium Sets a medium deceleration level for unauthenticated access logins. Set by default. Do not change this setting if you use Horizon Client version 4.8.
    High Sets a high deceleration level for unauthenticated access logins. Setting a high deceleration level might increase the log in time and affect the end-user experience.
  6. (Optional) To prevent any client that does not support login deceleration from connecting to VMware Horizon with unauthenticated access, select Block Non-Compliant Clients.
    Horizon Clients earlier than version 4.8 are not compliant.
  7. Click OK.

What to do next

Log in to Horizon Client with unauthenticated access and start the published application. See, Unauthenticated Access From Horizon Client.