Just because Amazon doesn’t offer an ISO doesn’t mean you cannot experiment with Fire OS or emulate the experience. Below are the best legitimate methods to get what you are actually looking for.
If you own an actual Fire Tablet, you can extract the system firmware (a .bin or .img file, not an ISO) to back up or restore your device. This is useful for installing custom recoveries (like TWRP) or debloating Amazon software. fire os iso %5BBEST%5D download
Amazon is legally required to release the kernel source code for Fire OS because it uses the GPL-licensed Linux kernel. While this is not an ISO, advanced developers can compile their own version. Just because Amazon doesn’t offer an ISO doesn’t
Where to get the source (the real “best download” for tinkerers): This is not for regular users
This is not for regular users. It is for developers porting Fire OS to other devices.
Let’s address the elephant in the room. Amazon has never, and will never, release an official ISO file for Fire OS.
Amazon is a hardware-first company. Unlike Google (which provides Android ISOs for developers) or Canonical (which provides Ubuntu ISOs), Amazon has no interest in supporting Fire OS on generic hardware. Distributing a Fire OS ISO would undermine their business model, which relies on selling affordable hardware locked into the Amazon ecosystem.