If you previously had a free ESXi 6.x or 7.x key, you must generate a new one for ESXi 8. Old keys do not work.
VMware ESXi 8.0 Update 3e now available as a Free Hypervisor esxi 8 license key free
If you are running a home lab and the closure of the free ESXi tier has left you stranded, is currently the top recommendation. If you previously had a free ESXi 6
Broadcom offers a for ESXi 8. This is not a trial; it is a perpetually free version for single servers. esxi 8 license key free
The days of simply registering on VMware’s old site are over. Since Broadcom acquired VMware, the process has changed. Here is the current legal method: