Public developer preview for Teams


Features included in preview may not be complete and may undergo changes before becoming available in the public release. They are provided for testing and exploration purposes only. They should not be used in production applications.

Developer Preview is a public program for developers, which provides early access to unreleased features in Microsoft Teams. Developer Preview allows you to explore and test upcoming features for potential inclusion in your Teams app. We also welcome feedback on any feature in developer preview. Developer preview is enabled per Microsoft Teams client, so you don't need to worry about affecting your entire organization.

Developer preview app manifest

Many features enabled in developer preview require alterations to your app manifest (previously called Teams app manifest) JSON file. To do so, you need to use the developer preview app manifest schema. If you use this schema, you can't use Developer Portal for Teams to make these changes, nor you can use it to upload your app for testing. To upload your app, you need to select the More apps icon on the app bar, then select the Upload a custom app link. Using this method, you can only upload a zipped version of your app package.

You might find it useful to use Developer Portal for Teams to create the non-developer preview portions of your app package, then export that package and manually edit the manifest.json file to add the developer preview features you wish to use. After you added the developer preview features to the manifest.json file, you can't reimport the package into Developer Portal for Teams.

Enable developer preview

Developer preview is enabled on a per-client basis, but the option to turn on developer preview is controlled at the organization level. To enable the option to turn on developer preview for an individual, you must ensure that they have the ability to upload custom apps. For more information, see setting up your tenant.

Using an app that contains developer preview features might cause clients that haven't enabled developer preview to behave unexpectedly. If you don't see an entry for developer preview, the most likely reason is your organization isn't configured for app uploading.

On a desktop or web client


If your tenant is enrolled for Microsoft 365 Targeted Releases, developer preview is automatically enabled and the developer preview switch isn't available.

To enable the public developer preview on a desktop or web client:

  1. Enable custom app upload for your developer tenant. For more information, see enable custom app upload.
  2. Select the ellipsis (...) menu next to your user profile to display the Teams menu.
  3. Select About > Developer preview.
  4. Select Switch to Developer preview.

On a mobile client

To enable the public developer preview on a mobile client:

  1. Enable custom app upload for your developer tenant. For more information, see enable custom app upload.
  2. Open the hamburger menu on the top left, then select Settings.
  3. Select About.
  4. Turn on the Developer preview toggle.


If you enable custom Teams apps and turn on custom app uploading doesn't enable developer preview features in Microsoft Teams set the update policy.

Disable developer preview

Use the same menu item under About → Developer preview and select it to turn it off.

See also

Test and debug your Microsoft Teams app