DSL vs. Cable: Broadband Internet Speed Comparison

Choosing between DSL and cable high-speed internet

Both a digital subscriber line (DSL) and cable internet services offer higher speeds than technologies such as dial-up modems. Both are popular and secure services, although each approach offers a competing mix of trade-offs. We've reviewed both types of broadband internet to help you choose the one that best suits your needs.

Illustration of a DSL and Cable store next to each other with posters extolling their services
 Lifewire / Jo Zixuan Xiuan

Overall Findings

DSL
  • Slower speeds than cable.

  • No peak usage issues.

  • Generally lower priced than cable with contracts that lock in rates for 1-2 years.

Cable
  • Significantly higher bandwidth supported.

  • High bandwidth positively impacts speed.

  • Competitively priced, although rates might increase after 6-12 months.

Cable high-speed internet and DSL services are available across the country, although in a few areas, only one is available. Most forms of DSL reach speeds of less than 100 Mbps. Cable technology currently supports approximately 1000 Mbps of bandwidth (and some as high as 2000 Mbps) in many areas.

Provide higher levels of bandwidth than DSL internet services on average; this bandwidth roughly translates to raw speed. However, several technical and business issues could reduce or eliminate the speed advantage of cable.

DSL vs. Cable: Real-World Speed

DSL
  • Moderate range speeds of 10-25 Mbps.

  • Adequate for light to medium use.

  • Ideal for homes with low streaming needs.

Cable
  • Multiple speed levels available.

  • Adequate for heavy streaming.

  • Service could be slower depending on area usage.

In practice, the speed advantage of cable over DSL is less than the theoretical numbers suggest. Cable modem services can slow down significantly if many people in a service area access the internet simultaneously.

Both cable modem and DSL performance vary from one minute to the next, depending on the pattern of use and traffic congestion on the internet.

DSL and cable internet providers sometimes implement speed caps that limit the bandwidth of their services.

Some home networks cannot match the speed of the internet connection, which lowers performance.

About Speed Caps

Both cable and DSL service providers commonly employ bandwidth and speed caps for residential customers. Bandwidth caps place an artificial limit on the amount of data a customer can use in a month. Companies control the maximum speed a customer can achieve by monitoring traffic flow and throttling network packets

Service providers offer several reasons for imposing bandwidth and speed caps:

  • Providers concerned about the capacity limits of their network may implement a cap to accommodate more customers.
  • Providers may believe that the majority of customers do not need more bandwidth than that allowed under the cap.
  • Providers may want to create a fair-and-equal distribution of bandwidth of customers. Without a cap, for example, some DSL subscribers would enjoy higher bandwidth levels than others in the same neighborhood.
  • Some providers allow a certain amount of data transfer each month to combat high bandwidth usage. When a customer goes over that amount, the company slows down the data connection or charges an additional fee.
  • Providers that want to charge higher or lower rates for greater or lesser speeds do so through a modem setting. That way, the company can increase the speed when a contract is upgraded.

Tips to Improve Internet Speed

Whether you have high-speed cable or DSL service, you can improve connection speeds in several ways:

  • Reduce the number of devices that use the connection to download, stream, and play games.
  • Security cameras and other smart home devices affect speed.
  • Wireless connections are slower than wired connections. Connect the computer to the router with an Ethernet cable for the fastest speed. 
  • Update the router and modem to the current specifications. A five-year-old modem probably can't handle the speeds your service provides. 
  • With wireless connections, the distance from the router makes a difference. The closer the device is to the router, the faster the wireless speed. 

Final Verdict

When you're shopping for a new service, ask about speed and bandwidth limits. You'll likely find that the company you deal with offers several packages with increasingly faster connection speeds for increasingly higher prices.

Your choice is guided by three primary factors:

  1. How you use the internet in your home.
  2. Your budget.
  3. Services available in your area.

If you have a large family, and everyone streams movies on their personal devices, the smallest package won't be sufficient. If you use the internet for email and occasional web surfing, go for the smaller package.