Latency is the time it takes for data to travel from your device to a server and back

When you click a link, type a message, or move your mouse in a video game, that action has to travel across the internet to a server somewhere, get processed, and come back to you. Latency measures how long that round trip takes, usually in milliseconds (ms). A latency of 50 ms means your action takes 50 thousandths of a second to reach the server and return.

This is different from speed, which measures how much data moves per second. You can have fast speed — a 500 Mbps connection — but high latency, which makes everything feel sluggish. You can also have slower speed but low latency, which often feels snappier for everyday tasks like email and web browsing.

Latency matters because humans notice delay. When you type in a search box and the results appear when ready, that is low latency. When there is a noticeable pause, that is high latency, and it happens regardless of how much speed your connection has.

Key Takeaways

  • Latency is measured in milliseconds and shows how long a round trip of data takes, not how much data moves per second.
  • For web browsing and email, latency under 100 ms feels responsive; for online gaming or video calls, under 50 ms is noticeably better.
  • Your internet provider, the distance to the server, and the type of connection (fiber, cable, or satellite) all affect your latency.
  • You can measure your latency using a ping test, which sends a small packet of data to a server and times how long it takes to return.

Why latency matters for different activities

Different online activities tolerate latency differently. Watching a video can handle 100 ms or more of latency because the video is buffered — downloaded ahead of time — before you watch it. Browsing websites and checking email feel fine with latency under 100 ms. Most people do not notice the delay at that level.

Online gaming, video calls, and real-time multiplayer games are much more sensitive. A latency of 100 ms in a video call means a half-second delay between when you speak and when the other person hears you, which breaks the feeling of conversation. In competitive gaming, 100 ms can mean the difference between hitting your target and missing. Professional gamers often aim for latency under 20 ms.

For everyday tasks — email, social media, shopping — anything under 100 ms feels when ready to most people. The jump from 50 ms to 150 ms is noticeable. The jump from 150 ms to 200 ms is very noticeable.

What causes high latency

The physical distance between you and the server matters. Data travels at the speed of light through fiber optic cables, but even at that speed, distance adds up. A server across the country introduces more latency than a server in your city. This is why some online games have servers in different regions — to keep latency low for players in each area.

Your type of connection affects latency too. Fiber optic connections typically have latency between 5 and 20 ms. Cable internet usually sits between 20 and 50 ms. Satellite internet, which bounces signals to space and back, often has latency of 500 ms or higher, making it unsuitable for gaming or video calls.

Network congestion also raises latency. When many people on your network are downloading large files or streaming video, your data has to wait in line, and the round trip takes longer. This is why your connection might feel sluggish during peak hours even though your speed test shows the same read numbers.

How to measure your latency with a ping test

A ping test measures latency by sending a small packet of data to a server and measuring how long it takes to return. You can run a ping test on any device with internet access. On Windows, open Command Prompt and type ping google.com. On Mac or Linux, open Terminal and type the same command. The results show the time in milliseconds for each packet sent and received.

You will see four lines of results. Look at the "time=" number on each line — that is your latency to that server in milliseconds. The last line shows the average. A ping to Google from most home connections returns 20 to 50 ms. If your ping is consistently above 100 ms, you have higher latency than typical.

For a more detailed picture, you can ping different servers. Ping a server close to you (your internet provider's server) to see your baseline latency. Then ping a server far away (like one on the opposite coast) to see how distance affects your numbers. This shows you whether high latency is a local problem or a distance problem.

The difference between latency and jitter

Jitter is the variation in latency — how much your latency bounces around from one moment to the next. A connection with 50 ms latency that stays at 50 ms is stable. A connection that jumps between 30 ms and 100 ms has high jitter, even though the average might be 50 ms.

High jitter is often more annoying than high latency. In a video call, consistent 100 ms latency is tolerable. Latency that jumps from 50 ms to 200 ms to 80 ms feels choppy and broken. Gaming with high jitter causes rubber-banding, where your character jumps backward suddenly because the server and your device disagreed about where you were.

When you run a ping test, look at the range of numbers. If they are all close together, your jitter is low. If they vary widely, you have jitter problems. Jitter usually comes from network congestion or an unstable connection, not from your internet provider's service.

How to lower your latency

If your latency is high, the first step is to identify where the problem is. Run a ping test to your internet provider's server (you can find the address on their website). If that latency is high, the problem is between you and your provider — a weak Wi-Fi signal, a failing modem, or a line issue. If that latency is low but pings to distant servers are high, the problem is distance or routing, which you cannot fix.

For Wi-Fi problems, move closer to your router or switch to a wired connection with an ethernet cable. A wired connection eliminates the wireless hop and often reduces latency by 10 to 30 ms. If your modem is old or overheating, restart it by unplugging it for 30 seconds and plugging it back in. If that does not help, contact your provider — they can test the line and replace the modem if it is failing.

For gaming or video calls, choose servers in your region when possible. Most games let you pick a server location. Choosing a server closer to you reduces latency significantly. You cannot change the speed of light, but you can reduce the distance the data has to travel.

When to upgrade your connection type

If you have satellite internet and need low latency for gaming or video calls, you need a different connection type. Satellite latency is a physics problem — the signal has to go up to space and back down — and no amount of troubleshooting fixes it. Fiber optic or cable internet are the alternatives if they are available in your area.

If you have cable internet and your latency is consistently above 100 ms even to nearby servers, contact your provider. They can check whether your line is congested or whether you need a newer modem that supports the latest standards. Some older modems introduce unnecessary latency.

If you have fiber optic internet and your latency is still high, the problem is likely on your end — your Wi-Fi, your device, or network congestion from other devices. Switching to a wired connection usually solves it.

Frequently Asked Questions

Is 100 ms latency good or bad?

For web browsing, email, and video streaming, 100 ms is fine — most people do not notice it. For video calls, it is noticeable but tolerable. For online gaming, it is on the high side and may affect your performance. Under 50 ms is considered good for most activities.

Can I reduce latency by changing my DNS?

Changing your DNS server (the service that translates website names into addresses) can sometimes reduce latency by a few milliseconds, but it is rarely the main cause of high latency. If your latency is very high, DNS is not the problem. If it is already acceptable, changing DNS probably will not make a noticeable difference.

Why is my latency higher at night?

Network congestion increases in the evening when more people are online. Your internet provider's network gets busier, and your data has to wait longer in queues. This raises latency and jitter. If your latency is fine during the day but high at night, congestion is the cause, and you may need a faster plan or a different provider.

Does a VPN increase latency?

Yes, using a VPN adds latency because your data has to travel to the VPN server before going to its final destination. The increase is usually 10 to 50 ms depending on how far the VPN server is. If latency is critical for gaming or video calls, avoid VPN for those activities.

What latency should I expect with my internet type?

Fiber optic: 5 to 20 ms. Cable: 20 to 50 ms. DSL: 30 to 70 ms. Satellite: 500 to 700 ms. These are typical ranges; your actual latency depends on distance to the server and network congestion. If your latency is much higher than these ranges, contact your provider.