Cat5e vs Cat6: Which Ethernet Cable Do You Actually Need?

Short answer. Cat5e carries gigabit Ethernet to the full 100 metre channel, and it also carries 2.5G and 5G under the 802.3bz standard, so for most homes and small offices it is not the bottleneck. Cat6 doubles the tested bandwidth to 250 MHz, uses a thicker conductor, and adds 10 Gigabit over shorter distances. If you are buying patch cords for existing gigabit gear, Cat5e is genuinely fine. If you are pulling cable into a wall you will not reopen for fifteen years, buy the headroom.

What actually differs

The multi-gig surprise

The most useful thing to know about Cat5e is the thing least often mentioned: when the industry needed speeds between 1G and 10G, it deliberately designed them to run on cable that was already in the walls. 2.5GBASE-T and 5GBASE-T were standardised in 2016 precisely so that a building full of Cat5e could get faster without anyone opening a ceiling. So if your new router, access point or NAS has a 2.5G port, the Cat5e already running to it will very probably carry it at full distance.

10 Gigabit is where the cable starts to matter. Cat6 will do it, but only over a shortened run, and how short depends on how many other 10G cables are bundled alongside it. That is why the 10G answer is normally Cat6A rather than Cat6.

When Cat5e is still the right buy

• Patch cords for gigabit switches, routers, consoles, TVs and printers — the port is the limit, not the cable.
• Runs to devices that will never exceed 1G: cameras, access points on gigabit uplinks, IoT and control gear.
• Tight conduit and crowded pathways, where a thinner cable is the difference between finishing the pull and not.
• Bulk reels for a large fit-out where the equipment is firmly gigabit and budget matters.

When to pay for Cat6 or more

• Anything going inside a wall, floor or ceiling. Labour dwarfs cable cost. The cable is the cheapest part of a run you will not redo for a decade or more.
• Runs you expect to carry 10G. Cat6 works over short distances; Cat6A works to 100 m and is the honest answer for a 10G backbone.
• Heavy PoE. A 23 AWG conductor sheds heat better than 24 AWG, which matters when a bundle is carrying high-power PoE to a lot of devices at once.
• Long horizontal runs near the distance limit, where headroom protects you against a marginal termination.

What about the cable already in your walls?

Look at the jacket. Cable is printed with its category and usually its gauge and fire rating along the length. If the print has worn off, plug in a device and check the negotiated link speed — the network will tell you what the cable is delivering. Existing Cat5e that links at gigabit is doing its job, and replacing it to get a number on a box is rarely money well spent.

Common questions

Will a Cat6 cable make my internet faster?
Almost never. Your internet speed is set by your service, and any category from Cat5e up carries far more than a typical connection. Cable category changes what your local network can do between devices.

Can I mix Cat5e and Cat6 in the same run?
You can, and the link will work — but the channel performs to its weakest component. A Cat5e patch cord on a Cat6 horizontal run gives you Cat5e performance for that link.

Is Cat5 the same as Cat5e?
No. Plain Cat5 predates the "e" (enhanced) revision and was not specified for gigabit. If your cable says Cat5 with no "e", it is old enough to be worth replacing.

Does Cat6 need special connectors?
Not for Cat6 UTP — standard RJ45 plugs and keystone jacks rated for the category will do. What matters is that the connector is rated for the category and that you keep the untwist at the termination as short as possible.

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Cat5e cables · Cat6 cables · Cat6A cables · Bulk cable by the 1000 ft box

Related guides

Cat6 vs Cat6a: which do you actually need? · What Ethernet cable for 2.5G and 10G? · How long can an Ethernet cable run actually be? · Cable and connector glossary