Guides · Comparison

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.

Jean Gilles · Founder & editor
Published Sep 17, 2026 · Updated Sep 17, 2026 · 6 min read
The short answer

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 data cap and a rate increase when the promo ends.

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CenturyLink
DSL and fiber, depending on address
Xfinity
Cable, very wide reach
Technology
DSL over copper, or fiber where built
Cable, with limited fiber
Upload speed
Symmetrical on fiber; very slow on DSL
A fraction of download speed
Data cap
None
Capped in most markets, with a paid unlimited add-on
Annual contract
None
Optional in some markets
Price over time
Flat, no year-two step up
Low intro rate, steps up after the promo
Speed tiers
Few
Many, from entry level to multi-gig

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 applies a data allowance in most of its markets, with an unlimited add-on available for a monthly fee. For a great many households the cap is irrelevant — normal streaming and browsing does not come close. For households with several heavy 4K streamers, large game downloads, cloud backup, or anyone working with video files, it becomes a real cost that belongs in the comparison.

If you expect to buy the unlimited add-on, add it to Xfinity’s monthly price before comparing. 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, with the unlimited add-on included if you will need it.

More on this topic
What replaced CenturyLink? CenturyLink vs. Spectrum Data caps explained Check your address
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Founder & editor

Jean founded ShopHighSpeed after trying to find one straight answer about business internet in his own town. He builds the site’s rankings from the availability data providers file with the FCC rather than from provider marketing.

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