Currently we have two variants of the vSphere GUIs which includes the vSphere Web Client and HTML5-based vSphere Client in vSphere 6.5 to manage the operation of virtual datacenter.
With the decommissioning of windows based vSphere client, VMware also introduced the HTML5 based vSphere client with vSphere 6.5. Which provides the solid performance as compared to the vSphere web client. The vSphere Client was introduced first in the Fling, then supported with vSphere 6.5. Since its introduction, the vSphere Client has received positive responses from the vSphere community and customer base.
With the recently released vSphere 6.5 Update 1, the vSphere Client got even better and is now able to support most of the frequently performed operations. With each iteration of the vSphere Client additional improvements and functionality are being added.
By the time the vSphere Web Client is deprecated, the vSphere Client will be full featured but with significantly better responsiveness and usability.
The HTML based vSphere Client will be the primary GUI administration tool for vSphere environments starting in the next release. It is recommended that customers should start transitioning over to the HTML5 based vSphere Client as the vSphere Web Client will no longer be available after the next vSphere release. This announcement from VMware gives ample time to customers to prepare for the eventual vSphere Web Client deprecation.