Bandwidth vs. Latency: What is the Difference?At HighSpeedInternet.com we commonly get asked, “Why is my internet so slow?” Many factors can contribute to a slow internet connection. The first step to diagnosing your particular issue is understanding that “slow” can mean two very different things.
- Slow internet can be caused by low bandwidth.
- Slow internet can be caused by high latency.
What is bandwidth?Bandwidth is what almost all internet service providers call “speed” in commercials and marketing. That can be a little misleading, because high bandwidth will not always result in an internet connection that feels fast to you. Bandwidth is measured in Mbps or megabits per second. Your internet connection will have two bandwidth numbers: download speed, and upload speed. Most ISPs only talk about download speed, because download speed matters most to most people. Unless you’re sending files, upload speed matters less.
What is Latency?Latency is the delay between when you click something and when you see it. It’s the time it takes for your request for data to get to a server (like a website), and then for the data to get back to you. Latency is measured in milliseconds, abbreviated “ms”. Most people will begin to notice delays of about 150-200ms. “Ping” is another word that is often used interchangeably with latency. “What’s your ping?” is another way of asking, “What is your delay/latency (in ms) to the server?”
So what’s the difference between bandwidth and latency?It’s easiest to explain the impact of each in some hypothetical scenarios:
- If your bandwidth is good and your latency is bad: Web pages would take a long time to start loading, but once the initial connection was made the rest of the page would load almost instantly.
- If your latency is good and your bandwidth is bad: Web pages would begin to load almost instantly, but the page would load slowly, one piece at a time.
Again, “good bandwidth” means bigger numbers, measured in Mbps. “Good latency” means a low response time, also called ping, which is measure in ms.Think of your internet like a water pipe, where you’re sending water out through one pipe and bringing it in through another. Bandwidth is like the size of the pipe and the volume of water it can send or receive at any point. Latency is like water pressure; it’s the speed at which water goes through the pipe.
Why does latency vs. bandwidth matter?
Gaming actually doesn’t need “fast” internet in the sense that it’s usually marketed. Bandwidth is relatively unimportant (except for getting game patches faster), but latency is key. Low ping times are highly-prized in fast-clicking twitch games like Call of Duty or Battlefield.
Streaming video or audio is mostly a matter of bandwidth, but latency can also cause problems. In theory a high-bandwidth connection with high latency would work, but in practice it rarely does. Most streaming services aren’t equipped to buffer long enough to stream seamlessly, even with a major buffering wait at the beginning. There are apps like NightShift that pre-load streaming content for high-latency users, but at that point you’re essentially downloading videos and not streaming at all.
Video chat works best with low latency. It will still work with high latency, but you’ll have to work with the awkward delay in the conversation. HD video streaming will require more bandwidth, but the blurry sort of chat most of us are used to will only require a couple Mbps.
Browsing works best with decent latency. While you can get by with high latency, it can be frustrating that you have to wait several seconds every time you visit a new page. More bandwidth doesn’t hurt, either, especially if you’re looking at high-res images, gifs, or video.
Which services have good bandwidth, and which have good latency?Most wired connections have fairly low latency. DSL and cable generally have 10-30ms response times within the US. Fiber is slightly faster at 5-20ms depending on equipment and location. Unfortunately, there is no way to know what your latency is going to be before purchasing, but generally it will be acceptable on wired connections. Satellite internet is notorious for high latency. Many games are difficult or impossible to play on satellite internet, because the signal must literally go to space and back. The majority of the delay is in processing and re-transmitting the signal. We don’t generally recommend satellite Internet due to bandwidth concerns when a wireline connection is available.
|Technology||Example providers||Average DL speed||Average latency||Providers|
|Cable||XFINITY by Comcast, Charter Spectrum, Cox Comunnications||41 Mbps||28ms||See cable providers|
|DSL||AT&T, Frontier, CenturyLink||16 Mbps||44ms||See DSL providers|
|Fiber||AT&T, Frontier, CenturyLink||73 Mbps||17ms||See fiber providers|
|Satellite||Hughesnet||7 Mbps||603ms||See satellite providers|
Lynn Phillips is a writer, social media marketer and illustrator. In her spare time she plays video games (badly) with her cat.