Latency

What is latency?

Latency is the delay between when you do something on your device and when the other side responds. It's measured in milliseconds (ms) and often called "ping time" or RTT (round-trip time).

Think of it like mailing a letter: latency is how long it takes for your letter to arrive and for a reply to come back. A letter across town takes less time than one across the country—the same is true for data traveling across the internet.

Common causes of high latency

Your internet connection type matters a lot. Satellite internet (like Viasat or HughesNet) has inherently high latency—often 600ms or more—because signals must travel to space and back. Older DSL connections also tend to have higher latency than cable or fiber.

Network congestion at home is another common culprit. If someone in your house is downloading a large game, streaming 4K video, running Windows updates, or using BitTorrent, your video calls will suffer. This is especially true with older cable modems that don't handle competing traffic well (see bufferbloat).

Distance to servers also plays a role. Connecting to a VPN server on another continent, or video calling someone far away, naturally adds latency that can't be avoided.

Why it matters

High latency makes everything feel sluggish. On a video call, you'll notice people talking over each other because of the delay. In online games, your actions happen a split second after you press the button.

For web browsing and email, latency is less noticeable since you're not expecting instant feedback. But for real-time activities—video calls, gaming, remote desktop—low latency is essential.

What you can do

Before an important call:

• Ask others in your household to pause downloads, streaming, and gaming
• Use a wired Ethernet connection instead of WiFi if you can
• Move closer to your WiFi router if you must use wireless
• Close other apps on your computer, especially anything syncing to the cloud
• If using a VPN, try disconnecting or switching to a closer server

Long-term fixes:

• Upgrade your internet service—fiber has the lowest latency, followed by cable, then DSL
• If you've been renting a modem from your ISP for years, buying a newer one (like a current Arris or Motorola model) can help significantly
• If you're on satellite internet, consider switching to a ground-based option if available in your area
• Contact your ISP if latency is consistently high—they may have a routing issue on their end

What Network Weather shows you

Network Weather measures latency to multiple destinations and shows you where delays are occurring. These thresholds align with recommendations from Zoom, Microsoft Teams, and Cloudflare's network quality research.

Zoom recommends latency under 150ms for good call quality. Microsoft Teams suggests under 100ms for optimal performance.