Yes, you can often use your existing router with fiber optic internet, but there are crucial considerations. Understanding compatibility, potential limitations, and when an upgrade is necessary will ensure you get the most out of your high-speed connection. The first sign it's time to get a Wi-Fi router replacement is if your hardware is more than three years old. That's because it won't be Wi-Fi 7 compatible and is likely causing a bottleneck. You'll notice this as latency in critical apps, especially if your home is device heavy.