The cable that works best depends on what your internet provider installed and what speed you're paying for

The physical cable running from your wall to your modem is either coaxial cable (the thick one with a metal connector, used for cable internet) or fiber-optic cable (thinner, used for fiber internet). You do not choose between them — your provider chose when they wired your building. What you can control is whether the cable you have is actually capable of delivering the speed you're paying for, and whether it's in good condition.

Most homes have coaxial cable because cable internet is more widely available than fiber. If you have fiber, your provider installed a special fiber-optic line to your house and a box called an optical network terminal (ONT) that converts the signal so your modem can use it. The cable itself is not something you upgrade or replace on your own — it's part of the provider's infrastructure.

What you can control is the cable between your modem and your router, and whether your coaxial cable is in good shape. A damaged or old cable can slow your connection even if your provider is sending faster speeds to your modem.

Key Takeaways

  • Coaxial cable (cable internet) and fiber-optic cable (fiber internet) are installed by your provider, not chosen by you.
  • If your coaxial cable is damaged, kinked, or more than 10 years old, replacing it may restore speeds your provider is already sending.
  • The cable between your modem and router should be a short, high-quality Ethernet cable if you want the fastest possible connection to your devices.
  • Fiber-optic cable is faster than coaxial cable, but only if your provider offers it in your area — availability depends on where you live.
  • You cannot upgrade the main cable running to your house yourself; contact your provider if you suspect damage or want to know what type you have.

Coaxial cable: what most homes have

Coaxial cable (often called "coax") is the standard for cable internet. It's the thick cable with a metal connector on each end, usually white or black. Inside, it has a copper core surrounded by insulation, a metal shield, and an outer jacket. The metal shield protects the signal from interference from other electronics in your home.

Coaxial cable can carry speeds up to about 1 gigabit per second (Gbps) in real-world conditions, though most cable internet plans max out at 500 Mbps to 940 Mbps. If your provider is sending you 300 Mbps and your cable is damaged or old, you might only receive 150 Mbps or less. The cable itself is not the bottleneck for most people — the bottleneck is usually the plan you're paying for — but a bad cable can make a fast plan slow.

Coaxial cable degrades over time, especially if it's been kinked, exposed to sunlight, or run through extreme temperature changes. If your cable is more than 10 years old or visibly damaged, ask your provider to inspect or replace it. Many providers will do this at no charge because they want you to actually receive the speeds you're paying for.

Fiber-optic cable: faster, but not everywhere

Fiber-optic cable uses light pulses to carry data instead of electrical signals. It's thinner than coaxial cable and can carry much higher speeds — typically 500 Mbps to 2 Gbps for residential plans, with some providers offering 5 Gbps or higher. Fiber is also less affected by interference and distance, so the signal stays strong even in large homes.

The catch is availability. Fiber requires a dedicated line from the provider's network to your house, and that infrastructure is expensive to build. As of now, fiber is available in some urban and suburban areas, but most rural areas do not have it. You cannot choose fiber if your provider has not wired your neighborhood for it.

If fiber is available at your address, it is almost always faster than cable internet for the same price or less. The main reason to choose cable over fiber is if fiber is not offered in your area, or if you're locked into a long-term cable contract.

The cable between your modem and router matters more than you think

The cable running from your modem to your router is an Ethernet cable, and it's one of the few cables you actually control. If you're using Wi-Fi, this cable does not matter. But if you're plugging a computer, gaming console, or streaming device directly into your router with an Ethernet cable, the quality of that cable affects your speed.

Ethernet cables are labeled by category: Cat5e, Cat6, Cat6a, and Cat8. For most homes, Cat6 or Cat6a is the right choice. Cat5e is older and maxes out at 1 Gbps; if you have a gigabit internet plan or faster, Cat5e will slow you down. Cat6 handles up to 10 Gbps, and Cat6a handles the same but over longer distances without signal loss. Cat8 is overkill for home use and is expensive.

Buy a cable that is as short as you need — a 6-foot cable is better than a 50-foot cable because longer cables lose signal strength. If you need a long cable, Cat6a is more forgiving than Cat6. Avoid cheap cables from unknown brands; a reputable brand like Monoprice or Belkin will cost a few dollars more and last longer without developing connection problems.

When to replace your cable

Replace your coaxial cable if it is visibly damaged — crushed, kinked, or with the outer jacket torn. Also replace it if it is more than 10 years old and you're not getting the speeds your provider says you should. You can test your speed with a free tool like Speedtest.net; run the test on a device plugged directly into your modem with an Ethernet cable to get the most accurate result.

If your test shows you're getting significantly less than your plan promises, contact your provider before buying a new cable. They may send a technician to check the line for free, or they may tell you the cable is fine and the issue is elsewhere. Do not assume the cable is the problem without testing first.

For Ethernet cables between your modem and router, replace them if they are visibly damaged or if you're experiencing frequent disconnections. A damaged Ethernet cable is rare, but it does happen — pets chew them, they get pinched in doors, or they degrade from being coiled too tightly.

What you cannot do yourself

You cannot replace the main cable running from the street to your house. That cable is owned and maintained by your internet provider. If you suspect it is damaged — for example, if you see exposed wires or the cable is hanging loose — contact your provider and they will inspect and repair it.

You also cannot upgrade from coaxial to fiber on your own. That requires your provider to run a new line to your house, which is a job for their technicians. If fiber is available in your area, you can call your provider and ask them to install it, but there may be a wait or an installation fee depending on the provider and your location.

What you can do is keep your coaxial cable in good condition by avoiding kinks and extreme temperatures, and by replacing your Ethernet cables if they are damaged. These small steps can help you actually receive the speeds your provider is sending.

Frequently Asked Questions

Can I use any Ethernet cable between my modem and router?

Any Ethernet cable will work, but older Cat5e cables max out at 1 Gbps. If you have a plan faster than 1 Gbps, use Cat6 or Cat6a to avoid slowing down your connection. For plans under 1 Gbps, Cat5e is fine.

How do I know if my coaxial cable is bad?

Look for visible damage like kinks, crushed sections, or exposed wires. If the cable looks fine but you're getting much slower speeds than your plan promises, run a speed test on a device plugged directly into your modem. If the test shows low speeds, contact your provider — they can check the line for problems you cannot see.

Is fiber internet always faster than cable?

Fiber plans are typically faster than cable plans at the same price point, but the actual speed depends on the plan you buy, not the cable type. A 300 Mbps fiber plan is the same speed as a 300 Mbps cable plan. Fiber is faster because providers offer higher speeds over fiber lines.

Do I need to replace my cable if I upgrade my internet plan?

Only if your new plan is faster than 1 Gbps and you're using Cat5e Ethernet cables. If you're upgrading from 300 Mbps to 500 Mbps, your existing cables are fine. If you're upgrading to gigabit or faster, switch to Cat6 or Cat6a between your modem and router.

What if my provider says fiber is coming to my area soon?

Ask your provider for a timeline and whether you can sign up for a waitlist. Fiber rollouts can take months or years, and timelines change. Do not wait for fiber if you need internet now — switch to cable if it's available, and you can always switch to fiber later when it arrives.