Cisco Feature Navigator
For Cisco devices, you can use an online tool that is provided called the Cisco Feature Navigator.
You can use it as a registered Cisco user or as a guest. There you can browse all of Cisco’s devices and IOS platforms either by feature, or by IOS version, and you can even compare the capabilities of particular OSes and platforms. It’s the “go-to” place to find out what features are supported by what platforms.