Over the last few years, VMware been criticized by customers and industry reviewers for continuing to offer a Web Client that relies on Flash. The arguments against Flash are many; a security threat, requires a plugin, memory hog, and generally not liked by most IT administrators. It was clear VMware had to complete the move to HTML5, and finally, in vSphere release 6.5, they did.
What does the HTML5 vSphere Client provide? A client that is faster, can be used cross-browser and cross-platform, and a seamless end user experience. With what appears to finally be a successful replacement for the desktop C# client, the desktop client was no longer supported when vSphere 6.5 was rolled out. The vSphere Client managed vCenter; to manage a standalone host, administrators uses the ESXi Embedded Host Client.
The vSphere HTML5 Client has been available as a VMware Fling since last spring, so it has received plenty of use and generated much positive buzz. Unfortunately, not all of the functionality in the Web Client has been moved to the HTML5 vSphere Client so you will run them alongside each other for the time being.
A full list of functionality in the Web Client which has not yet been ported to the new vSphere Client can be found in VMware’s Functionality Updates for the vSphere Client document on their website.