CenturyLink vs. Xfinity
Xfinity is the bigger network and usually the cheaper first bill. Whether it is the better buy depends on uploads, caps, and what happens in month thirteen.
Where CenturyLink fiber is built, it is the better long-term connection: symmetrical uploads, no data cap, flat pricing. Xfinity wins on availability, on the range of speeds it offers, and on the first-year price — provided you can live with a rate increase when the promo ends.
- Quantum Fiber, CenturyLink's fiber brand, is now AT&T Fiber (Feb 2, 2026). CenturyLink copper stays with Lumen.
Establish which CenturyLink you are offered
As with every CenturyLink comparison, the first job is to find out whether the company can sell you fiber or only DSL at your specific address. These are not variations of one product; they are different networks with different ceilings. Fiber competes with Xfinity comfortably. DSL does not.
This matters more against Xfinity than against most rivals, because Xfinity’s cable plans reach very high download speeds. A DSL line is not in the same conversation.
Where CenturyLink fiber wins
Three things: uploads, caps and billing. Symmetrical fiber sends data out as fast as it pulls it in, which matters enormously if you work from home, back up to the cloud, or run cameras. There is no data cap to think about. And the rate is flat, so the price you sign up at is the price you keep paying.
Fiber also tends to be steadier under load, because you are not sharing a coaxial segment with the whole street at 8pm.
Where Xfinity wins
Availability first. Xfinity serves a very large share of US addresses, and in many neighbourhoods it is simply the fastest thing that exists. It also offers an unusually wide ladder of speed tiers, so you can buy close to what you actually need rather than rounding up.
Intro pricing is the other advantage. Xfinity promotional rates are often the lowest first-year number on the table. The catch is that the promotional period ends, and the step up can be substantial.
The data cap, honestly
Xfinity's new plans include unlimited data. Customers on older plans still have a 1.2 TB monthly cap, which matters for households with several 4K streamers, large game downloads, cloud backup or video work. If you're on an older plan and near the cap, switching to a new plan removes it.
When you compare, use Xfinity’s price after the promo or the 5-year guarantee price, not just the first-year rate. That single adjustment closes much of the gap against flat-rate fiber.
Which should you get?
Check your address, then apply a simple rule. If CenturyLink fiber is available, take it unless Xfinity is dramatically cheaper across two years rather than one. The upload difference alone justifies it for most working households.
Take Xfinity when CenturyLink has only DSL to offer, when fiber has not reached your street, or when you need a specific speed tier that CenturyLink does not sell. Just judge the price over twenty-four months, not only the first-year rate.
Which CenturyLink you're comparing
At a glance
Before you choose
- Check whether you're offered fiber or DSL at your address: check your address.
- If you pick Xfinity, check whether your plan includes the gateway before you buy a modem: stop renting your modem.
- Compare the price locks: price locks compared.
Related guides
Sources (1)
- Plan pages and Broadband Facts labels from AT&T Fiber, checked Oct 2026
Prices and offers change often; confirm at your address before you order. How we research
Questions
Is Xfinity better than CenturyLink?
Usually better than CenturyLink DSL. Against former Quantum Fiber, now AT&T Fiber, fiber usually wins on upload speed and has no data cap.
Does Xfinity have a data cap?
Not on new plans. Customers on older plans still have a 1.2 TB monthly cap; moving to a new plan removes it.
Jean founded ShopHighSpeed after trying to find one straight answer about business internet in his own town. He has been a Comcast and Verizon Fios customer, and ranks providers on what they actually deliver, not on what they advertise.