Reliability
Packet loss is often treated as a minor metric. A result of 1% can look harmless next to a fast download number. In practice, even a small amount of persistent loss can make a connection feel unreliable.
What happens when a packet is lost
TCP, the protocol behind most web traffic, retransmits lost segments. That adds delay and reduces effective throughput, especially on long-distance connections where the round-trip time is already high. UDP-based real-time traffic cannot always wait for retransmission, so the application has to conceal or skip missing data.
Why 1% can matter
At a steady 1% loss, roughly one in every hundred packets needs recovery. For a voice call sending many small packets, that can mean frequent micro-glitches. For a large download, it can noticeably reduce speed because of congestion-control backoff.
Where to look
- Wi-Fi signal strength and interference.
- Bad cables or a failing router port.
- Congestion on the local network.
- Problems on the provider's route.
If packet loss appears only in the evening, it may be congestion; if it appears on one device but not another, start with the local link. Run the test more than once and note whether the result is consistent.
Check your connection with our four-metric speed test.