What Is Latency? Understanding Ping, Jitter, and Lag

Defining Network Latency

Latency is the time it takes for a data packet to travel from its source to its destination. In networking, it's typically measured as round-trip time (RTT) — the time for a packet to reach a server and return — expressed in milliseconds (ms). When you run a ping test, the result you see is your latency.

Latency is fundamentally limited by physics. Data travels through fiber optic cables at roughly two-thirds the speed of light (~200,000 km/s). A signal crossing the continental United States (~4,500 km) has an absolute minimum travel time of about 22 ms — and that's just one way. Real-world latency adds time for routing, processing at each hop, and queuing at congested links.

Latency is distinct from bandwidth. Bandwidth describes how much data can flow at once (the width of the pipe), while latency describes how long each bit takes to arrive (the pipe's length). A satellite internet connection may have 100 Mbps of bandwidth but 600 ms of latency — fast but slow to respond.

Ping, RTT, and What the Numbers Mean

When people say "ping" in the context of gaming or network quality, they're referring to round-trip latency measured in milliseconds. Understanding what different values mean helps set realistic expectations:

• Under 20 ms — excellent; typical for local network connections or nearby servers
• 20–50 ms — very good; suitable for competitive gaming and video calls
• 50–100 ms — acceptable for most applications; some gamers may notice it
• 100–200 ms — noticeable delay; video conferencing still works but gaming suffers
• 200–500 ms — high latency; video calls become choppy, gaming is difficult
• Over 500 ms — very high; typical of geostationary satellite links; real-time interaction is impaired

Use our ping test to measure your current latency to multiple geographic locations. For the most accurate picture, test against servers in the same region as the services you care about (your game server, video conferencing provider, etc.).

What Is Jitter?

Jitter is the variation in latency over time. If your ping measures 30 ms, then 45 ms, then 28 ms, then 62 ms across successive packets, you have significant jitter. Whereas latency measures the average delay, jitter measures how consistent that delay is.

Jitter is especially damaging for real-time applications like:

• VoIP and video conferencing — jitter causes audio to break up, delay voice packets, or arrive out of order
• Online gaming — inconsistent ping causes "rubber banding" where players appear to teleport
• Live streaming — buffering strategies can absorb some jitter but cause delay

Jitter under 10 ms is generally imperceptible. Above 30 ms, real-time applications begin to degrade noticeably. Most VoIP systems use a "jitter buffer" that absorbs variation, but this introduces additional fixed latency as a tradeoff.

Common causes of jitter include network congestion, packet queuing at routers, wireless interference, and inconsistent processing times at overloaded servers. Run a speed test to check whether your connection shows elevated jitter alongside latency.

What Causes High Latency?

Latency has many potential sources, from your local network to the far end of the internet:

• Physical distance — the unavoidable speed-of-light delay for intercontinental connections
• Number of hops — every router adds a small processing delay; more hops mean more accumulated latency
• Network congestion — packets wait in queues at overloaded links, adding variable delay
• WiFi interference — wireless signal contention, interference from neighboring networks, and physical obstructions all increase latency on your local network
• Bufferbloat — oversized router buffers that hold too many packets, causing packets to sit in queue far longer than necessary
• ISP routing inefficiency — some ISPs route traffic through distant peering points unnecessarily, adding tens of milliseconds
• VPN overhead — encryption, decryption, and rerouting through a VPN server adds latency proportional to the server's distance

A traceroute is the best tool for isolating which part of the path contributes the most latency.

Latency vs Lag: Not the Same Thing

Gamers often use "lag" and "ping" interchangeably, but they describe different problems. Latency (ping) is a measurable network characteristic. Lag is a broader term describing any perceived unresponsiveness, which can stem from:

• Network latency — the actual round-trip time to the game server
• Server-side processing — an overloaded game server may respond slowly even with low network latency
• Client-side frame rate drops — a slow GPU or CPU causing low FPS looks and feels like lag but is entirely local
• Packet loss — lost packets that must be retransmitted add delay and cause stuttering
• Bufferbloat — a notorious cause of gaming lag that shows acceptable ping in idle tests but terrible performance under load

You can test for bufferbloat with the speed test while simultaneously downloading a large file — if your ping spikes dramatically during the download, your router likely has bufferbloat. Tools like the Bufferbloat Test at waveform.com give you a dedicated score.

Frequently Asked Questions