What Is Latency?
Network latency is the time it takes for data to travel from its source to its destination. Measured in milliseconds (ms), it represents the delay between sending a request and receiving a response. Low latency is critical for responsive web applications, real-time communication, and gaming.
How It Works
Latency is the sum of propagation delay (physical distance), transmission delay (data over the link), processing delay (routers/servers), and queuing delay (waiting in network buffers). The round-trip time (RTT) is the total time for a request and response, which is what most tools measure.
Why It Matters
High latency makes websites feel slow, disrupts video calls, and degrades real-time applications. For web performance, every 100ms of latency reduces conversion rates. CDNs, edge computing, and protocol optimization (HTTP/2, QUIC) help minimize latency.
Common Issues
- Geographic distance causing high baseline latency
- Network congestion during peak hours
- Too many network hops increasing cumulative delay
- Unoptimized server-side processing adding latency