CenturyLink vs. Ziply Fiber Internet Providers Compared

CenturyLink’s DSL internet has wide coverage but slower speeds

CenturyLink is a DSL internet provider owned by a parent company known as Lumen Technologies. Lumen is the seventh-largest ISP in the U.S., based on its combined internet service in both DSL and fiber. Lumen serves a total of about 3 million customers [1]. CenturyLink is the DSL brand owned by Lumen. The fiber brand of Lumen is now known as Quantum Fiber. This review will focus on the CenturyLink DSL half of the Lumen brand. We will cover Quantum Fiber in a separate review, because the two brands provide very different technologies. If your only available internet is CenturyLink, your DSL connection is likely to be slower than if you have cable or fiber. DSL speed can vary widely depending on your neighborhood and even on the wiring in your home. But CenturyLink, like most DSL companies, will charge you the same price for a slow 10 Mbps download speed as for 100 Mbps download speed. It’s luck of the draw, with no price break for slower service. DSL customers just aren’t getting the same kind of value that fiber customers are getting. And that’s one probable reason that Lumen separated its two brands. Now, it should be easy to tell what you’re getting – mostly.  CenturyLink is DSL, and Quantum Fiber is all-fiber. On websites that still mix the two names, though, the speeds of each plan will often be a giveaway. CenturyLink sold half of its DSL network to Brightspeed in 2022. CenturyLink now has a very unusual coverage footprint: think of it as the Western half of the United States, minus California, plus Florida.

CenturyLink DSL charges high prices for widely varying speeds

DSL is not one of the faster internet technologies on the market. Usually, DSL customers sign up for their plans because there is no cable or fiber internet in their areas. And that can be a valid choice if DSL will give you better performance than satellite internet, though you have to evaluate that on a case-by-case basis. Many times, DSL plans are good options for customers in rural areas. CenturyLink plans are no exception to the general qualities of DSL. You will generally pay around $50 for your DSL package, whether you get 10 Mbps download speed or whether you are lucky enough to get 100 Mbps download speed (very unusual for DSL and true for only 28% of CenturyLink DSL customers) [2]. In better news, CenturyLink’s DSL plans are free of data caps. So, despite the fact that CenturyLink’s DSL prices are high for the speeds, at least you won’t have unexpected data overage charges.

Ziply Fiber’s prices are unbeatable for all-fiber internet, but DSL internet is no bargain

Ziply Fiber is one of only a few fiber internet companies in the nation that offers a  rate of $/month for fiber internet. That’s a good deal! Ziply Fiber also offers  Mbps download/upload speed for $/month. If you are lucky enough to have access to Ziply Fiber's all-fiber network, you will save 30-40% over some competitors’ prices. But Ziply Fiber has the same split fiber/DSL profile as a couple of other start-up fiber providers. The existing network that Ziply Fiber took over from Frontier in 2020 was 70% DSL. Since then, Ziply Fiber has built out more fiber to bring fiber/DSL ratios to about 50-50 [4]. But there’s a good chance you may get DSL instead of fiber even if Ziply Fiber serves your area. And if you sign up for DSL, your prices will be much higher, even though you will get slower speeds. No matter what your DSL speed is, it won’t match the speed of Ziply Fiber’s first-tier fiber plan, and yet you will pay more for a DSL plan. That’s the way the industry works right now, and it’s certainly not fair to DSL customers. But on the positive side, Ziply Fiber’s pricing for both DSL and fiber is predictable because there are no data caps. You won’t have to worry about unexpected overage charges with a Ziply Fiber plan of either kind. You also won’t be required to sign an annual contract, which means you won’t face any early termination fees.

“But it was so fast in the ‘90s!” DSL shows its age in many locations

CenturyLink DSL uses one of the oldest internet technologies: copper cables originally designed as telephone wire. About 47% of CenturyLink customers achieve speeds up to 30 Mbps. On the flip side, a lucky 27% are able to achieve 80 Mbps or more, delivering a much better experience [5]. If DSL gives you under 10 Mbps download speed and only 1 Mbps upload speed, you won’t be able to play real-time games online with any kind of reliability. You may also experience glitching if multiple people stream or videoconference at the same time. To be fair, some DSL connections will give you faster speeds. However, if you are considering ordering CenturyLink DSL, be sure to research your other options. You can test your actual speed here to see what kind of performance your current internet connection is giving you.

Ziply Fiber is super-fast on its all-fiber network, but its DSL speeds vary widely

An all-fiber connection will give you much faster, more reliable internet access than a DSL internet connection. You'll get multi-gigabit speeds for both download and upload from your fiber plan. Ziply Fiber even offers speeds as high as 10 Gigs in some places! Though Ziply Fiber’s plan says that its DSL speed goes up to 115 Mbps download/7 Mbps upload, those numbers indicate a maximum speed. Your DSL could also be as slow as 7Mbps download/1 Mbps upload, which was the speed listed for one property we tested in Shoreline, WA [5]. Or, you could get the most common range for today’s DSL speeds, which tends to be about 10-25 Mbps download, 1-3 Mbps upload. Ziply Fiber will tell you what your estimated speed will be when you sign up, but you can also test your internet speed here. Clearly, there’s no comparison between these DSL speeds and even the  speeds of the lowest-level Ziply Fiber all-fiber plan. With slow DSL, you may not be able to stream in HD or play real-time games. But if you get Ziply Fiber plans that are 100% fiber, your household will be able to stream and game on multiple devices without glitches or freezing screens.

Option to use your own modem/router or self-install your connection

With the CenturyLink DSL plan, there’s a $15 a month modem/router rental fee, which is on the high end of equipment fees. You can avoid the modem/router fee by buying your own. And that might not be a bad plan, given that you will make up the price of a typical modem/router in a year or less. You may have to pay for a professional installation, which is usually a one-time fee of $99. Fortunately, in many places you may also have the option to self-install for $15. It depends whether there is still a working CenturyLink DSL connection in your home.

Optional equipment rental fees, free installation with Ziply Fiber plans

Ziply Fiber will provide DSL customers with a combined modem/router for between $10-20/month. You can use your own compatible modem and router to avoid the fee, but Ziply Fiber won’t be able to help you with any technical issues related to your personal equipment [6]. If you choose fiber internet from Ziply Fiber, you will get a Wi-Fi 6 fiber router for the same monthly rental fee of $10-20/month. Installation for all Ziply Fiber plans is free, which will save you up to $100 over standard ISP installation fees.

CenturyLink runs below average in some satisfaction rankings

CenturyLink’s customer satisfaction rankings vary widely by region on the J.D. Power survey [3]. In the North Central region, CenturyLink ranks above average. In the West, CenturyLink ranks slightly below average, and in the South, CenturyLink is second from last in customer satisfaction. The North Central and West regions where CenturyLink/Quantum Fiber rank higher are also the regions in which Quantum Fiber provides most of its fiber access. The South only includes one state with fiber internet coverage, which means most of that low customer satisfaction rating is based on CenturyLink’s DSL. According to the American Customer Satisfaction Index, CenturyLink's DSL service scored 62 out of 100 in 2025, which was the same score they received the previous year. For CenturyLink and Quantum Fiber, these customer satisfaction rankings tell the story clearly. CenturyLink’s DSL service is not as likely to please you. However, be aware that there is a certain amount of online cross-marketing between the two companies. So, if CenturyLink says they are able to sell you “fiber” as they seem to imply on their homepage, all that means is that they’re going to send you to a Quantum Fiber plan if your address has fiber availability.

Customer service about average

Ziply Fiber is still too small an internet provider to qualify for independent review in the J.D. Power survey of customer satisfaction for ISPs. A sampling of online user reviews indicates that most user complaints were related to billing and account administration, especially during the time of transition, right after Ziply Fiber took over its network from Frontier. The balance of positive and negative user comments leads us to award Ziply Fiber 3.5 stars for customer service. But overall, Ziply Fiber is an excellent choice if you have access to its all-fiber plans.