Quantum Fiber vs. Xfinity Internet Providers Compared

Quantum Fiber brings superior internet speeds and reliability at an appealing price.

Quantum Fiber is a fiber-optic network under the parent company Lumen Technologies, which also operates CenturyLink’s DSL-based service. According to the latest data from June 2025, the Federal Communications Commission states that Quantum Fiber is available to just over 2.3% of U.S. households, making it one of the largest fiber-optic networks in the United States [1]. The service operates in 18 states, as well as a number of cities, with the strongest coverage in Arizona, Colorado, Florida, Iowa, Minnesota, Nebraska, Oregon, Utah, and Washington [2]. In May 2025, AT&T announced plans to acquire Quantum Fiber's parent company for nearly $6 billion; the transaction is expected to close in 2026 [3]. AT&T has indicated that no immediate changes are planned and will continue to "prioritize putting customers first" following the acquisition. The sale ultimately resulted in Lumen reporting $915 million in losses for Q2 2025, with Lumen attributing losses to the accounting changes, and "not from money actually spent" [4]. Quantum Fiber delivers symmetrical fiber-optic speeds ranging from 200 Mbps to 8000 Mbps in select markets, with no data caps or contract requirements. The service stands out for its "Price for Life" guarantee, which locks in your monthly rate permanently—a significant advantage in an industry where 63% of customers reported price increases in the past year [5].

Great prices and a Price-for-Life Guarantee.

Quantum Fiber offers straightforward pricing that includes an autopay discount. Monthly costs are approximately $5 higher if you don't enroll in automatic payments. In most markets, the two primary plans available are the 500 Mbps and 1,000 Mbps (1 Gig) tiers. Multi-gigabit options—up to 2 Gig, up to 3 Gig, and up to 8 Gig plans—are available in select areas. All plans include free equipment rental during an initial period, unlimited data, and no contracts [7].

Value Analysis

When evaluating internet plans, the cost per megabit provides insight into true value. Quantum Fiber's entry-level 500 Mbps plan at $50 per month equates to 10 cents per Mbps—a competitive rate for fiber service. This pricing structure positions Quantum Fiber favorably against cable providers that may advertise lower introductory rates but dramatically increase rates after promotional periods end.

Fees and the Price-for-Life Guarantee

Quantum Fiber’s "Price for Life" guarantee locks in your plan rate permanently, making it a great deal. Unlike most cable internet providers that raise prices after the promotional period of one or two years, Quantum Fiber maintains your original rate indefinitely. If you sign up for the 200 Mbps plan at $30 per month, that rate remains locked in, even if the same plan later costs new customers $20 more. This guarantee applies specifically to your base service rate. Three potential cost increases are still possible:

1. Equipment rental fees: Quantum Fiber provides free equipment during an "initial period." After this period ends, rental fees may apply. You can drop these fees altogether by using your own compatible router.
2. Installation costs: Professional installation is currently free, though Quantum Fiber states this "could change in the future," and additional products or services might incur extra installation costs.
3. Taxes and miscellaneous fees: Local and state taxes and regulatory fees may increase over time, beyond Quantum Fiber's control.

No Data Caps or Contracts

All Quantum Fiber plans include unlimited data, allowing unrestricted internet use within the acceptable use policy without overage fees or speed throttling. The absence of contracts means you can cancel or modify service at any time without incurring early termination fees.

Xfinity stands above the pack for its low initial pricing, but pay attention to the later price hikes and fees

Xfinity is the largest internet service provider in the United States, with 32 million broadband subscribers [1]. Xfinity is a subsidiary of cable giant Comcast. Company size and strength gives Xfinity the ability to offer very low promotional prices to consumers for a year or even two years. Xfinity’s promotional plans begin around $40/month. Here's the kicker: after a year or two, your promotional rate will end. At that point, your rate can go up by anywhere from $25 to $50 per month. And Xfinity pricing varies all over the country and is pretty complex in how it changes from plan to plan. By our evaluation standards, this lack of simplicity in pricing hurts Xfinity’s rating despite its great initial promotional rates. In addition, Xfinity’s lower-tier plans have data caps that apply under certain conditions. The data cap is 1.2 TB (terabytes) per month, which is enough to cover many households’ monthly usage without any trouble. However, the Benton Institute for Broadband and Society analyzed data from OpenVault to show that 14.6% of homes used more than 1 terabyte per month, and 2.4% used over 2 terabytes per month [2]. This data suggests that 1 in every 7 homes would run a risk of exceeding the Xfinity data cap. Comcast/Xfinity claims that it does not throttle internet and slow it down, however, Xfinity will charge you overage fees if you exceed your data cap [3]. Those fees can go up to a maximum of $100/month [4]. Odds are that you won’t exceed your data cap. But if you have lots of real-time gaming or heavy streaming in your household, the extra cost for data overage could really add up. With Xfinity's top tier plans, though, you will get unlimited data.

Symmetrical upload and download speeds and superior reliability during peak usage times.

Quantum Fiber utilizes fiber-optic technology, which provides two key advantages over cable and DSL: symmetrical upload and download speeds, and superior reliability during peak usage times. Symmetrical speeds mean your upload capacity matches your download speed. On the 8000 Mbps plan, for instance, you receive 8000 Mbps in both directions. This is valuable for video conferencing, uploading large files, livestreaming, and cloud backups.

Fiber-to-the-Home vs. Fiber-to-the-Curb

In most installations, Quantum Fiber deploys Fiber-to-the-Home (FTTH), where fiber-optic cable runs directly to your residence. This provides the fastest possible speeds with full symmetrical performance. However, in some cases, Quantum Fiber may install Fiber-to-the-Curb (FTTC), where the final connection to your home uses coaxial cable. Even a short coaxial cable segment will reduce upload speeds compared to pure fiber. If you receive an FTTC connection, your download speeds may remain at the advertised levels, but your upload speeds will be slower than the symmetrical speeds typical of FTTH. Before installation, confirm which connection type your location will receive.

Performance Capacity

A gigabit fiber plan from Quantum Fiber supports about 10 devices simultaneously, enabling high-bandwidth activities (such as 4K streaming and online gaming) while maintaining smooth performance. The combination of low latency, high bandwidth, and consistent speeds makes fiber particularly well-suited for households with multiple heavy internet users.

Xfinity’s hybrid fiber/coaxial cable supplies gigabit download speeds but slower upload speeds

Though Xfinity has advanced cable technology and good speeds, their network seems to be more prone to outages than users would like [5]. That’s the major reason Xfinity gets a lower rating for performance, in addition to the intrinsic differences between cable speed and all-fiber speed. Xfinity uses technology that is mostly fiber but uses coaxial cable for a short stretch of your internet connection. This type of connection is known as hybrid fiber/coaxial cable, or HFC. An HFC internet connection is better than older cable technologies because it can supply download speeds up to gigabit speeds. HFC will give you faster, more reliable internet service than DSL, satellite internet, or fixed wireless internet. And for streaming in HD, this hybrid fiber- cable internet will certainly be able to support multiple devices. The major difference between HFC and an all-fiber internet connection is upload speeds. Your upload speed will be no faster than 35-50 Mbps. An-all fiber connection, by contrast, will give you the same upload speed as your download speed. Your upload speed will affect activities such as gaming, videoconferencing and large file uploads. The good news is that if you have an upload speed of 35 Mbps, you’re still going to be able to upload pretty quickly. For most average households, 35 Mbps is enough. But if you have four or more people in your household streaming HD, playing games, working from home, and videoconferencing simultaneously, you’re going to want all-fiber internet, or what is often called “fiber to the home” (FTTH). Xfinity does have one all-fiber connectivity option that is full FTTH. If your household’s location is eligible, Xfinity will install an FTTH connection for their Gigabit Pro plan. Gigabit Pro is up there with the fastest fiber plans on the market.

Get free use of a  360 Wi-Fi mesh router or use your own router

Quantum Fiber provides its 360 Wi-Fi equipment at no additional cost during an initial period. This system includes a SmartNID ONT device and up to four mesh Wi-Fi pods. The number of Wi-Fi pods will be determined by your installation technician based on your home's size. Most equipment has Wi-Fi 6 connectivity, but Wi-Fi 7 is available in select areas. The mesh network architecture offers better coverage than traditional single-router setups. This is beneficial for larger homes or properties with thick walls that impede wireless signals. The 360 Wi-Fi system creates whole-home connectivity by placing pods throughout your space, eliminating dead zones and ensuring seamless handoff as you move between areas. This setup supports the high device counts and bandwidth demands typical of modern households.

Professional Installation

Quantum Fiber currently provides free professional installation. The internet provider has noted this "could change in the future," and customers requiring additional products or services may incur extra installation costs. Professional installation ensures proper fiber-optic connection, optimal equipment placement for your home's layout, and immediate resolution of any technical issues. The installation process:

• Running fiber-optic cable to your home (FTTH) or to the curb (FTTC)
• Installing the SmartNID ONT
• Positioning mesh Wi-Fi pods throughout the home
• Testing connection speeds and performance
• Explaining system features and troubleshooting resources

Xfinity offers two different gateways and popular Flex 4K streaming TV box

For TV fans, Xfinity internet service brings the added bonus of its free Flex 4K streaming box [6]. This convenient gadget will work much like a Roku box to consolidate your streaming apps, plus give you over 10,000 free movies and shows, free channels, and a voice remote. Xfinity TV customers are not eligible for a free Flex 4K, however. For your modem and router, you will get the xFi Gateway with its multi-gig speed capability, Wi-Fi 6E, parental controls and security protection [7]. Or you can upgrade to the xFi Complete, which includes unlimited data. Both require a rental fee after the promotional period that could be $15-25, which is part of why your price goes up. If you use your own router and modem to avoid the equipment fee, you will have to live with the 1.2 TB data cap. Installation fees will be similar to other providers at around $100 for a technician install and $15  for a self-install ($15).

Quantum Fiber ratings often skewed by CenturyLink

According to the 2025 American Customer Satisfaction Index (ACSI) report comparing internet providers, Quantum Fiber scored 71 out of 100 points—a 7% decline from the previous year. This places Quantum Fiber four points below the fiber industry average of 75 [3]. The 2025 ACSI data also indicated that overall fiber provider scores decreased by 1% year-over-year across the industry [8]. The J.D. Power 2024 U.S. Residential Internet Service Provider Satisfaction Study did not differentiate between Quantum Fiber and CenturyLink DSL, instead reporting combined results for Lumen Technologies. In the West, where Quantum Fiber has its strongest presence, Lumen Technologies ranked last with a score of 511 out of 1,000. This combined scoring methodology means CenturyLink's lower-performing DSL service likely impacted the overall rating. If you compare fiber and DSL services within the Lumen portfolio, the ACSI shows Quantum Fiber's fiber service scores 16 points higher than CenturyLink's DSL offerings. This gap showcases that fiber customers report better experiences than DSL subscribers. The 7% satisfaction decline and below-average ACSI score suggest Quantum Fiber has customer experience downfalls regardless of its technical advantages. Issues affecting its customer experience ratings likely include installation delays, equipment problems, billing discrepancies, and customer service responsiveness. Reddit backs this up, with some users frustrated with Quantum Fiber's reliability: "The speed is great, consistent 550mbps up and down, but it is so unreliable" [9]. Other subscribers report a more positive experience, but do note that they are utilizing their own equipment instead of the Quantum Fiber-supplied equipment: "Love [Quantum Fiber], just get your own wifi equipment" [10]. Despite the below-average satisfaction scores, Quantum Fiber remains a strong technical choice where available. The combination of fast symmetrical speeds, unlimited data, no contracts, competitive pricing, and the price-for-life guarantee creates genuine value.

Xfinity Customer Service shows improvement

Xfinity has not been known for strong customer service over the years. Online reviews continue to mention some problem areas. But Xfinity has been moving up in official rankings, and for that reason, we give them 4 stars for improving their customer experience. Xfinity has customer support on its website, with 24/7 chat for help and 24/7 tech support. An online status center allows you to check for outages and troubleshoot your service. The Xfinity app will make your online customer experience more streamlined. You can also find Xfinity help communities through Facebook, Twitter, and Reddit. Customer service rankings have been improving for Xfinity in recent years. In 2022, Xfinity ranked third in three of four regions in the J.D. Power Residential Internet Service Provider Customer Satisfaction Study  [8]. This ranking reflects Xfinity’s recent effort to improve their customer support. Though Xfinity’s customer support ratings from other sources are not always as high, overall, signs are getting better that you will be satisfied with your customer experience.