High latency means your data takes longer to travel, even if you have plenty of bandwidth

Latency is the time it takes for a single piece of data to travel from your device to a server and back. It is measured in milliseconds. A speed test might show you have 100 Mbps of read speed — plenty of bandwidth — but if your latency is 150 milliseconds, your web pages will still feel sluggish. Bandwidth is how much data you can move. Latency is how fast it moves. You need both.

High latency creates lag. When you click a link, your browser sends a request to a server. That request has to travel there, and the response has to travel back. If that round trip takes 200 milliseconds instead of 20, you notice the delay. In video calls, high latency makes conversations feel unnatural — you talk over each other because the audio is arriving late. In online games, it makes your character move after you press the button. In everyday browsing, pages load slower even though your connection is fast.

Key Takeaways

  • Latency under 50 milliseconds is good for most tasks; anything above 100 milliseconds will feel noticeably slow in real use.
  • Your internet service provider's network, the distance data travels, and congestion on shared lines all affect latency in ways you cannot control directly.
  • WiFi adds latency compared to a wired connection, especially if your router is far away or the signal is weak.
  • Background programs and devices using your connection can increase latency even if they are not using much bandwidth.
  • Restarting your modem and router, moving closer to your router, or switching to a wired connection are the fastest ways to lower latency.

Your internet service provider's network is often the source

Your ISP controls the path your data takes to reach the wider internet. If that path is long, congested, or poorly maintained, your latency will be high. Some ISPs route traffic inefficiently — your data might take a longer path than necessary to reach a server. Others oversell their network, meaning too many customers are sharing the same lines, which slows everything down during peak hours.

You can see this by running a ping test to your ISP's gateway (usually your modem's default gateway, which you can find in your router settings). If that latency is already high — say, 50 milliseconds or more — the problem is between you and your ISP, not in your home network. If the gateway latency is low but latency to distant servers is high, the problem is the path your ISP uses to reach those servers, which you cannot fix without changing providers.

Distance and geography add unavoidable delay

Data travels at the speed of light through fiber optic cables, but it cannot travel faster than that. If you are on the West Coast and connecting to a server on the East Coast, your data has to physically travel across the country. That journey takes time — roughly 20 to 30 milliseconds one way, so 40 to 60 milliseconds round trip. If you are connecting to a server in another country, add more time.

This is why gaming servers, video streaming services, and content delivery networks place servers in multiple locations. A server closer to you means lower latency. If you are consistently connecting to distant servers for work or gaming, you are stuck with that latency unless you move or the service opens a server nearer to you. There is no setting in your home that will speed up the speed of light.

WiFi introduces latency that a wired connection avoids

Wireless connections are convenient but slower than ethernet cables. WiFi adds latency because your device has to negotiate with the router, handle interference from other devices, and retransmit packets that did not arrive cleanly. The farther you are from your router, the worse this gets. A device sitting next to the router might see 5 to 10 milliseconds of WiFi latency. A device in another room might see 30 to 50 milliseconds.

If you are experiencing high latency and you are on WiFi, plug in an ethernet cable and run a latency test again. If it drops significantly, WiFi is your problem. Move your router to a central location, away from walls and metal objects. If that does not help enough, a wired connection is the most reliable fix. For gaming, video calls, or any task where latency matters, ethernet is worth the inconvenience of a cable.

Congestion on your home network raises latency for everyone

If someone in your home is downloading large files, streaming video in 4K, or running a backup, they are not just using bandwidth — they are also creating congestion that raises latency for everyone else. Your router has to manage all these requests, and if it is overwhelmed, even a straightforward web request will wait in queue.

Check what is connected to your network. Open your router's admin page (usually 192.168.1.1 or 192.168.0.1 in your browser) and look at the connected devices. Disconnect anything you are not using. If someone is downloading, ask them to pause it. Restart your router — unplug it for 30 seconds, then plug it back in. A fresh start clears the queue and often lowers latency noticeably.

Your modem or router may be outdated or failing

Older modems and routers are slower at processing data. A modem from 2015 will add more latency than one from 2023. If your modem or router is more than five years old, it may be time to replace it. Check with your ISP — they sometimes provide newer equipment if you ask, or you can buy your own.

A failing device also raises latency. If your modem or router is overheating, has loose cables, or is crashing and restarting, latency will spike. Feel the device — it should be warm but not hot. Check that all cables are firmly connected. If the device is crashing (you lose internet for a few seconds at a time), restart it. If restarting does not help, it may need replacement.

Background programs and updates consume resources

Windows updates, antivirus scans, cloud backups, and other background tasks use your internet connection and your device's processing power. While they are running, latency can spike. Check your Task Manager (Windows) or Activity Monitor (Mac) to see what is using your network. If you see something unexpected, close it or schedule it for a time when you are not working or gaming.

Windows Update is a common culprit. It runs in the background and can consume significant bandwidth and CPU. If you are experiencing high latency during the day, check whether an update is running. You can pause updates temporarily in Settings > Update & Security > Advanced Options.

Frequently Asked Questions

What latency is acceptable for normal internet use?

Under 50 milliseconds is ideal. Between 50 and 100 milliseconds is acceptable for most tasks like browsing and email. Above 100 milliseconds becomes noticeable — pages feel slower, video calls lag, and online games become frustrating. For gaming specifically, many players prefer under 50 milliseconds.

Can I lower latency by changing my DNS?

Changing your DNS server (to something like Google's 8.8.8.8 or Cloudflare's 1.1.1.1) can sometimes lower latency slightly, but usually only by a few milliseconds. It is worth trying if you are already troubleshooting, but it is not a primary fix. The real latency problem is usually your ISP's network or your WiFi connection, not your DNS.

Why is my latency high only at certain times of day?

Network congestion varies by time. During evening hours, more people are using the internet, and your ISP's network gets crowded. Your latency rises because your data is competing with everyone else's. This is normal and usually temporary. If it happens every evening, your ISP may be overselling capacity during peak hours.

Does restarting my modem really lower latency?

Yes, often. Restarting clears the modem's memory, resets its connection to your ISP, and can resolve temporary issues that raise latency. Unplug it for 30 seconds, then plug it back in and wait for all lights to stabilize. Run a latency test before and after to see if it helped.

Is high latency the same as a slow internet connection?

No. You can have fast bandwidth and high latency at the same time. A speed test might show 100 Mbps, but if latency is 200 milliseconds, web pages will feel slow. Conversely, you can have lower bandwidth but acceptable latency, and the connection will feel responsive. Both matter, but they are different things.