Example implementations relate to multi-tenant upgrading. Some implementations may receive a request to upgrade a first tenant from an original version of an application to a new version of the application. The new version of the application may be backwards compatible with the original version. Some implementations may also upgrade the first tenant to the new version in response to the request while data according to the original version is simultaneously being provided to a second tenant. Additionally, some implementations may also provide data according to the new version for tenants that have completed the upgrade and provide data according to the original version of the application for tenants that have not upgraded.