My internet download and upload speeds look normal on every device, but latency has become highly unstable. While gaming, ping repeatedly jumps between roughly 10 and 200 ms, causing constant stuttering. The same spikes occur on my PC over a wired connection, even when no games or other demanding programs are running. I can also notice pauses when scrolling through social media or watching videos on my phone. The connection is provided through fiber or cable service, and my ISP has already sent technicians, replaced the router, tried different router placement, and said there is nothing more they can do. I am testing new Ethernet cables, but I would like ideas for determining whether the problem is inside my home, with the ISP signal, or farther along the internet route.
3 Answers
The first step is finding where the latency starts instead of immediately replacing more equipment. On Windows, run continuous pings to your router, then to a reliable internet address, and use TRACERT or PATHPING to the game server. If the ping to your router spikes, the issue is inside your home network or with the modem/line. If the router stays stable but the first ISP hops spike, the provider or local signal is likely responsible. Spikes only farther along the route may be an upstream routing or game-server issue that your ISP may not control.
Testing with a known-good Ethernet cable is reasonable, but cables are less likely to be the cause if several devices are affected. Also try connecting one computer directly to the modem or fiber gateway, bypassing any separate router if your setup allows it. If the spikes remain, compare a continuous ping to the gateway with one to an external address. A different network adapter can be tested as well, but upgrading hardware will not fix an ISP-side or upstream latency problem.
Since this affects multiple devices and even a wired PC, check for a line or signal problem rather than focusing only on Wi-Fi. Ask the provider to review the optical or modem signal levels, error counts, packet loss, and the connection’s event logs. A speed test can still look perfectly normal while intermittent packet loss or signal errors cause high latency. Keep a timestamped record of the spikes and results from continuous pings so the ISP has something more specific to investigate.
The provider has already sent technicians, but I’ll ask specifically about signal errors and packet loss instead of just download speed. The phone interruptions may also be related to the same line issue.

The spikes also happen with only one browser tab open, so I’ll test the router and outside addresses separately. I’ve noticed videos pausing on my phone too, which makes me suspect this is not limited to gaming.