Catch the spikes first
Spikes are intermittent by definition, so a short test often misses them. Run the 60-second stability test, which draws every packet on a timeline. A spike shows as a tall tower above an otherwise flat strip. The detail panel counts "spiky seconds", seconds where the median ping more than doubled or loss passed 5%. Note when the towers appear: evenly spaced, in clusters, or at random.
What the pattern tells you
| Spike pattern | Likely cause |
|---|---|
| Regular, every few seconds | Wifi background scanning, or a device's power-saving mode |
| One long rise lasting several seconds | Another device starting an upload or download |
| Random, clustered, only on wifi | Interference or a crowded channel |
| Every evening, not in the morning | Provider congestion |
| Only in one game | That game's servers or the route to them |
| Constant, on a cable, any time | Line fault or a failing router |
The usual causes, and their fixes
- Wifi scanning. Many laptops and phones pause to scan for other networks every few seconds, causing short regular spikes. Updating the wifi driver, disabling location services that trigger scans, or using a cable stops it.
- Power saving. Wifi adapters on battery power sleep between packets. Set the adapter's power mode to maximum performance, or plug the laptop in.
- Someone else's traffic. An upload filling your line causes a sustained rise, the classic symptom of bufferbloat. Smart queue management on the router is the fix; pausing the upload is the quick test.
- Game and system updates. Consoles and PCs download updates on their own schedule. Check the download queue on every device.
- Interference. Microwave ovens, baby monitors and a neighbour's network on the same channel cause random spikes on 2.4 GHz. Switch to 5 GHz or a less crowded channel.
- Router overload. Spikes that grow worse over days and vanish after a restart point to the router; if they return quickly, it may need replacing.
- Provider congestion. Nothing to change at home; report it with timestamped results, or change plan or provider.
Spikes you cannot fix from home
If a stability test on a cable is flat and a game still spikes, the spikes are happening beyond your provider: on the route to the game or at its servers. Check the game's server status page and its own network overlay, which often distinguishes client-side and server-side problems. Trying another region can confirm it. At that point your line is not the problem, and the only useful action is reporting it to the game's support with your clean test result as evidence.