What Is Ping and Latency?
Ping and latency are both measures of how long it takes for data to travel between two points on a network. Latency is the generic term for this delay; ping is the most common tool used to measure it. High latency makes real-time applications like online gaming, video calls, and VoIP feel sluggish, laggy, or choppy - Even when you have plenty of bandwidth.
Latency, Jitter, and Round-Trip Time
| Term | Definition | Impact | Good Value |
|---|---|---|---|
| Latency (one-way delay) | Time for a packet to travel from source to destination | Determines how "snappy" real-time apps feel | <20ms (local), <80ms (gaming) |
| Round-Trip Time (RTT) | Time for a packet to reach destination and return - What ping reports | Directly affects web page load initiation and game responsiveness | <50ms excellent, <150ms acceptable |
| Jitter | Variation in latency between successive packets | Causes audio glitches and video buffering in real-time streams | <10ms for VoIP/gaming |
| Packet loss | Percentage of packets that never arrive | Triggers TCP retransmission; causes choppy VoIP; visible lag spikes in games | 0% ideal; >1% problematic |
How the Ping Tool Works
The ping command sends ICMP Echo Request packets to a target host and waits for ICMP Echo Reply responses. Each reply reports the round-trip time in milliseconds. The standard ping sends a configurable number of packets (default 4 on Windows, unlimited until interrupted on Linux/macOS) and reports min/avg/max RTT and packet loss percentage. Example: ping google.com on Windows or macOS.
What Causes High Latency
- Physical distance - Signals travel at roughly two-thirds the speed of light through fibre, so London to Sydney carries ~80ms of irreducible propagation delay.
- Network congestion - Queuing delays at overloaded routers and switches add variable latency (bufferbloat).
- Wi-Fi interference - Wireless contention and retransmissions add 5–50ms over a wired connection in the same location.
- VPN overhead - Encryption and routing through an additional server adds 10–40ms depending on server location and protocol.
- ISP routing inefficiency - Some ISPs route traffic suboptimally, adding unnecessary hops. Use traceroute to diagnose.
- To reduce latency: use a wired Ethernet connection instead of Wi-Fi; choose the geographically closest servers; use low-latency protocols (WireGuard for VPN, UDP for games). Measure your baseline with the speed test.