What Is Latency and How Do You Fix It? | Reviews.org

What causes latency?

Latency is affected by several factors: distance, propagation delay, internet connection type, website content, Wi-Fi, and your router.

Some of these factors are fixable, while others are just part of everyone’s online experience. So if you’re wondering why your latency is so high, here are some likely culprits.

1. Distance

Distance is usually the main cause of latency—in this case, it refers to the distance between your computer and the servers your computer is requesting information from.

For example, if you live in Madison, Wisconsin, and you visit a website hosted by a server located in Chicago, Illinois, the response time of the website should be pretty quick. That’s because your request has to travel a relatively short distance of 147 miles and back.

But if you live in Miami, Florida, and try to access that same website hosted by a server in Chicago, the response time will be slower. This is because your request has to travel 1,381 miles to the Chicago server and back to you in Miami.

What is round-trip time (RTT)?

Round-trip time (or RTT), is the amount of time it takes for your request (like hitting enter on a Google search) to reach a server, and then have that server’s response get back to your computer.

Your request → the server’s response → your computer

2. Propagation delay

Real quick, let’s talk about propagation. In physics, propagation is “the sending out or spreading of light or sound waves, movement, etc.”1 When we’re talking internet, propagation is the action of sending out your data packets to a server.

Your data packet → the server

This brings us to propagation delay: this is how long it takes for your data packets to reach that. (But it doesn’t include the time it takes to cross the full distance  back to your computer—that’s round-trip time.) Propagation delay is just one piece of the puzzle when it comes to how much latency you experience.

3. Internet connection type

Your internet connection type can also play a role in how high or low your latency is. For the most part, DSL, cable, and fiber internet tend to have lower latency, while satellite internet tends to have higher latency.

Latency by connection type2,3

• DSL: 24–42 ms
• Cable: 15–27 ms
• Fiber: 10–15 ms
• Satellite: 594–612 ms

4. What’s on a website

Ever clicked on a link and waited several minutes for the website to load far too many GIFs, ads, or large images? Yup, you just experienced latency thanks to someone plastering The Office memes all over their Angelfire page.

If a website is home to lots of large files, like HD images or videos, or multiple third-party ads (the horror), your web browser has to download all of those files and ads to show them to you. And if those files or ads are hosted on a server that’s far away from you, there’s going to be a little latency thanks to distance.

5. Wi-Fi vs. Ethernet cable

If you want to reduce your latency as much as humanly possible, you’ll want to use an Ethernet cable to connect to the internet.

Does Wi-Fi affect latency?

Wi-Fi is great, yes, but your wireless signal is more susceptible to noise, meaning your data packets likely need to be re-sent, or retransmitted, if they become lost.

Wi-Fi also has to jump through a few more hoops, like encryption protocols, to travel back and forth from your computer. And usually, those wireless signals fade, or lose strength, over distance faster than an Ethernet connection.

6. Your router

An old, slow router can bog down your computer’s connection to your internet provider’s modem, whether you use Wi-Fi or an Ethernet connection. This is especially true if your router doesn’t support the internet speed you’re paying for or if you have a lot of people and devices connected to your router at the same time.

Upgrading to a new router may decrease your latency, but, unfortunately, it likely won’t have too huge of an impact.

If your router comes with a Quality of Service (QoS) feature, enable it.

Some modern routers come with a feature called Quality of Service (QoS). By enabling QoS, you can tell your router to prioritize certain traffic over others.

For example, you can tell your router to prioritize your desktop computer over your kiddo’s tablet. This means that your computer gets the best possible online performance, possibly at the cost of your child’s tablet getting a slower internet connection. (Shh, we won’t tell.)