A router’s security is ultimately going to be determined by its software which is properly called its firmware. All routers run this, and sometimes the router vendor will release a new version to add features and fix bugs.
Here’s a list of the most popular routers, and links to where their firmware can be downloaded from:
3rd Party Firmware
Software from your router vendor is not always your only choice for what to run on your router. Many routers also run firmware that was written and distributed by a 3rd party. Typically, this is seen as a good alternative with many more features than what your vendor produces, and often better security.
Here’s a short list of 3rd party firmware that we like. Check the specifications to see whether it will run on your router.