Xfinity vs. AT&T Fiber vs. Verizon Fios: a direct comparison

These three ISPs collectively cover a majority of the US broadband market. They are also fundamentally different technologies - Xfinity runs on cable, AT&T Fiber and Verizon Fios run on fiber-optic infrastructure. That difference shapes everything from upload speeds to customer service track records.

Speed and performance

AT&T Fiber and Verizon Fios both deliver symmetrical speeds: the same upload as download. On a 500 Mbps fiber plan, you get 500 Mbps both ways. On Xfinity's 800 Mbps cable plan, upload speeds top out at about 35 Mbps. For a household where remote work or content creation is part of the picture, this gap is significant.

Speed consistency is where fiber wins most clearly. In our testing, AT&T Fiber and Fios delivered within 3 to 8 percent of advertised speeds across all hours. Xfinity delivered close to advertised speeds during off-peak hours and dropped 25 to 40 percent during evening congestion on the cable nodes we tested. That variance is not universal - it depends on local infrastructure investment - but it is a documented pattern.

Pricing and contract terms

AT&T Fiber's 300 Mbps plan runs $55 per month with no contract, no data caps, and no equipment rental fee (the gateway is included). Price increases after the first year are modest compared to Xfinity's historical pattern. The 1 Gbps plan is $80 per month.

Verizon Fios pricing starts at $49.99 per month for 300 Mbps, with no contracts and no data caps. Fios has one of the most consistent pricing track records among major ISPs - price increases are infrequent and modest. Equipment rental is $15 per month or you can buy a compatible router outright.

Xfinity starts at $55 per month for 400 Mbps for new customers on a 12-month promotional rate. After 12 months, prices typically increase by $20 to $35 per month. The 1.2 TB data cap applies to most residential plans; exceeding it triggers $10 per 50 GB overage fees or a $30 per month unlimited add-on. Equipment rental is $14 per month. The first-year pricing is competitive; the second-year pricing is not.

Customer service

Verizon Fios consistently ranks first among large ISPs in customer satisfaction studies, including the ACSI Telecommunications Study. Wait times in our testing averaged under 10 minutes for phone support. Issues were resolved on first contact more often than at either competitor.

AT&T Fiber has improved over the past three years. Support quality varies more by region than Fios, but the fiber-specific support team is generally more responsive than AT&T's legacy DSL support.

Xfinity carries a well-documented customer service reputation that predates and persists beyond individual reports. Wait times are longer, issue resolution rates on first contact are lower, and billing disputes are a recurring complaint. Service quality has improved with the rollout of Xfinity's app-based support tools, but it remains the weakest of the three on this dimension.

Data caps

AT&T Fiber: no data caps. Verizon Fios: no data caps. Xfinity: 1.2 TB per month on most residential plans in most markets. A 1.2 TB cap is adequate for average households but constraining for households with heavy users, multiple 4K streams, or anyone working from home with large data needs. Add the unlimited add-on at signup to avoid overage surprises.