Cat5e vs Cat6 vs Cat6a: which cable does a home need?

Most people who ask which cable to use are about to have it put inside a wall, where it will stay for as long as they own the house. For a home the short answer is Cat6, and the longer answer is that the category matters less than how the run is put in and finished at each end. If you would rather have it done once and tested, that is data cabling for homes, run and tested. Below is what each category carries as the standards define it, what we put in and why, and what to check before you pay for anything new.

Which cable should a home use: Cat5e, Cat6 or Cat6a?

Cat6, for nearly every home. It carries gigabit comfortably over any run a house has, costs little more than Cat5e to put in, and leaves headroom for faster plans and faster equipment. Cat6a is worth it on a few particular runs, and Cat5e is fine where it is already in the wall and tests good.

The reason is practical. The cable is the cheap part of a data point; the time goes into getting it from the hub to the room, and that time is the same whichever category goes in. So there is nothing saved by putting in the older one, and while the wall is open, a second cable takes the same time to pull as the first.

What is Cat6?

Cat6 is Category 6 network cable: four pairs of copper wires twisted together inside one jacket, ending in the same eight-pin plug, called RJ45, that fits every ethernet port in the house. The category is a performance grade. Category 6 is defined for signals up to 250 MHz, against 100 MHz for Cat5e and 500 MHz for Cat6a, and the higher the figure, the more data the cable can carry over the same distance.

Every category uses the same plug, so a Cat6 lead works in a Cat5e socket and the other way round. A link runs at the level of its weakest part, though, which is why mixing categories in one run gains nothing. On cable already in the house, the category is often printed along the jacket.

Cat5e vs Cat6 vs Cat6a: speeds and distances

All three carry gigabit over the full 100 metres the standards allow. The difference is 10 gigabit: Cat5e is not rated for it, Cat6 carries it to about 55 metres, and Cat6a carries it the whole 100 metres.

What each category carries, as the standards define it

Category	Rated to	Gigabit	10 gigabit	Where it belongs
Cat5e	100 MHz	Yes, to 100 m	Not rated	Fine where it is already in the wall and tests good
Cat6	250 MHz	Yes, to 100 m	About 55 m, as little as 37 m in the worst case	The default for a home
Cat6a	500 MHz	Yes, to 100 m	Yes, to 100 m	Long or heavily shared runs, offices
Cat7	Not a TIA category	Yes, with RJ45 ends	At the level of the plug	Not a home cable
Cat8	2000 MHz	Its channel is defined to 30 m only	Built for 25 and 40 gigabit, to 30 m	Data centres, switch to server

Pick a cable

Cat5e Cat6 Cat6a Badly finished

Four twisted pairs

Gigabit

10 gigabit Not rated for 10 gigabit worst case, tight bundles

Device end Hub end

0 m25 m50 m75 m100 m

90 m fixed

100 m in all

• Patch lead
• Fixed cable

Cat5e

Cat5e carries gigabit the full 100 metres. It is not rated for 10 gigabit. Fine where it is already in the wall and tests good.

Cat6

Cat6 carries gigabit the full 100 metres, and 10 gigabit to about 55, as little as 37 where many cables are bundled tight. The default for a home.

Cat6a

Cat6a carries 10 gigabit the full 100 metres. It is thicker and stiffer, and needs more room to bend. Worth it on a long or heavily shared run.

Badly finished

The same Cat6, with one pair loose at the socket. The category no longer matters: the run fails at the end, and only a test shows it.

The 100 metres is the whole channel, from the device to the switch: up to 90 metres of fixed cable in the walls and short patch leads at each end. Cisco’s cabling guide for 10 gigabit (opens in a new tab) sets out the same layout. A house rarely needs a run anywhere near that long, so for gigabit, distance is not what separates the three.

The Cat6 figure for 10 gigabit is the one to read carefully. The standard expects about 55 metres, and where many cables are bundled tightly together, as little as 37. Measure your longest run before you decide: under 37 metres, Cat6 carries 10 gigabit even in the worst case, and up to about 55 it usually will.

Cat6 vs Cat6a: when is the heavier cable worth it?

Cat6a is worth it where a single run is long or carries a lot: the trunk from an NBN box in the garage to a switch in the middle of the house, a run to a ceiling access point, or a home office that moves big files between machines. Everywhere else in a house, Cat6 does the same job.

Cat6a is rated to 500 MHz and carries 10 gigabit the full 100 metres. The price of that is size. It is thicker and stiffer, with tighter twists and more insulation around the pairs, which is what stops them interfering with each other, and it needs more room to bend through a wall cavity or round a corner in the roof space.

The trunk is the run our technician singles out. When everything in the house comes back through one cable from the box, that cable is shared by every device, so it is the one to make the best. The other way to give that run headroom is two Cat6 cables instead of one, which takes no longer to pull.

Cisco recommends Cat6a or better for new installations, and Panduit recommends it for 10 gigabit. Both are writing for offices and data centres, where that is sound advice. A house is a different job, and Cat6 is what we put in unless one of the runs above calls for more.

What about Cat7 and Cat8?

Neither is a home cable. Cat8 is built for 30 metre links between switches and servers in a data centre, and Cat7 is not a category the American cabling standard recognises at all.

• Cat8 is rated to 2000 MHz and carries 25 and 40 gigabit over channels of up to 30 metres, for the link from a switch to a server. Nothing in a house runs at those speeds, and 30 metres is a data centre length, not a house one.
• Cat7 comes from the international standard, where it uses connectors that are not RJ45 and will not fit your router. Panduit’s note on Category 7 (opens in a new tab) explains that a Cat7 cable with ordinary RJ45 ends performs at the level of the plug, which is Cat6 or Cat6a.

So a lead or a reel marked Cat7 or Cat8 will plug into your gear and work, but it will not make a home network any faster than Cat6. If a quote for a house names either one, it is fair to ask why.

What matters more than the category?

How the run is put in and how each end is finished. A Cat6 run with one pair left off, a join in the middle or a socket wired differently at each end will do worse than a tidy run of Cat5e, and nothing printed on the jacket will show it.

These are the things that decide whether a run works:

• One continuous cable, with a socket at each end. Data cable is not joined inside the wall. Where two runs have to meet, each gets its own socket and a short patch lead goes between them.
• All eight wires, in the same order at both ends. Ports wired for a phone on a single pair, or wired to a different scheme at each end, are among the most common reasons a socket in the wall does nothing.
• Solid-core cable in the walls. Fixed runs use solid wires, which hold in a wall socket or patch panel and carry the signal further. Stranded wire is for patch leads.
• Kept clear of power. Cabling here is run to AS/CA S009:2020, the wiring rules for customer cabling: data cable kept the required distance from power cable where the two run together, and a barrier between them where that distance cannot be kept.
• Not clipped tight to the frame. A cable stapled to the timber before the plasterboard went on can never be pulled out and replaced.
• Tested end to end before anything is plugged in, so a fault is found while the wall is still open.

The job on our WiFi technician page shows how this plays out. A large house had three ceiling access points, all lit up, and still a few megabits in the rumpus room. The cable to that room had an open circuit, a second run went through an old distribution box, and the patch panel had been terminated in the wrong pin order. None of that was about the category, and fixing it run by run brought every level back to the plan’s speed.

A quick test you can do yourself: if a laptop on a cable is fast at the NBN box and slow at the end of the run, the run or its ends are the problem, whatever is printed on the cable. Test from the router if the laptop gets nothing at the box: the box can stay locked to the old router until your provider clears it.

Check your speed first Test on a laptop with a cable straight into the router, then on the same laptop at the wall socket at the far end of the run. The same speed at both means the cable is doing its job.

Patch leads vs installed cable: what is the difference?

A patch lead is the short, flexible cable with a plug on each end that goes from a wall socket to a device. Installed cable is the solid-core cable inside the wall, ending on a socket or a patch panel. They are made differently because they do different jobs.

Stranded wires in a patch lead survive being bent, coiled and unplugged. Solid wires in installed cable are stiffer, carry the signal further, and are what wall sockets and patch panels are built to grip. The rule of thumb is simple: fixed runs are solid, leads are stranded, and a long patch lead pushed through a wall is not a substitute for a proper run.

The other difference is who can touch them. Buying patch leads and plugging them in is yours to do. Running cable through walls, ceilings or under the floor and fitting the sockets is work for a registered cabler, who signs a statement that the work complies with the wiring rules, as the ACMA explains (opens in a new tab). Whether you need a cabling licence goes through where that line sits.

A patch lead is also the first thing to swap when one device drops out on a cable. It is the part most likely to have been trodden on or kinked, and the easiest one to rule out.

Patch leads are the part you can buy and plug in yourself. These are ready-made leads in the lengths a home uses most.

We earn a small commission if you buy through our Amazon links, at no extra cost to you. As an Amazon Associate we earn from qualifying purchases.

Gear mentioned here, on Amazon Australia

Product	What it is for	Link
UGREEN Cat6 lead, 2 m	Laptop to modem, modem to switch	View on Amazon for the UGREEN Cat6 lead, 2 m (opens in a new tab)
UGREEN Cat6 lead, 5 m	A room-length run	View on Amazon for the UGREEN Cat6 lead, 5 m (opens in a new tab)
UGREEN Cat6a lead, 2 m	For 10 gigabit ports	View on Amazon for the UGREEN Cat6a lead, 2 m (opens in a new tab)
UGREEN flat Cat6, 10 m	Under a rug or along a skirting	View on Amazon for the UGREEN flat Cat6, 10 m (opens in a new tab)

Which cable goes outside or underground?

None of the indoor categories. Blue internal cable in a conduit under the yard takes in water and breaks down within a few years, so a run to a granny flat, a studio or a shed needs underground-rated cable, gel-filled to keep the moisture out.

The category of that cable is still Cat6; it is the jacket and the gel inside it that are different. NBN for a granny flat covers the run across the yard, and where a trench is not possible, a wireless bridge carries it instead. One more cable that is not interchangeable: an HFC NBN connection comes in on coax, and no category of data cable can carry it from the wall box to the NBN box.

Is the cable already in your walls good enough?

Usually, if it is Cat5e or Cat6 and it tests good. Pull a wall plate off before you pay for new cable, because what is behind it decides most of the job.

• Blue cable with eight wires is ethernet, and can usually be re-terminated and used.
• Thin cable with two or four wires is phone cable. It cannot carry ethernet, whatever socket is fitted to it.
• A black cable straight in from outside is the NBN line, and is left alone.

If the jacket says Cat5 rather than Cat5e, it is the older generation that 5e replaced, and an old run of it may not hold gigabit. That matters on a fast plan, and a test on the cable says whether yours is the limit before anything is pulled out. Replacing old cable is not always a matter of tying a new one to it and pulling: cable that has sat for years in a conduit in a slab can go stiff and brittle, and may snap partway.

How to set up a wired home network covers the hub, the patch panel and the route a new cable takes through each type of home. If you need more ports at the end of a run rather than more runs, a network switch, and how it differs from a router, is usually the answer.

A plug-in tester shows whether each wire in a run is connected end to end. It does not certify the speed, but it finds a broken or crossed pair.

Gear mentioned here, on Amazon Australia

Product	What it is for	Link
Klein LAN Scout Jr. 2	Checks every wire end to end	View on Amazon for the Klein LAN Scout Jr. 2 (opens in a new tab)

When you need a technician, and when you don’t

You do not need anyone to choose a category, buy patch leads or test a run with a laptop. If the cable is already in the walls, it is Cat5e or Cat6, and a laptop at the far end gets the same speed as at the NBN box, leave it alone. A newer category will not make it faster for anything a house does today.

You do need a registered cabler for anything that goes in the walls, the ceiling or under the floor. Our data cabling work tests what is already there before anything new is run, and puts in Cat6 by default, Cat6a where a run calls for it. The data cabling cost estimator gives a price range for your house in about two minutes, and how many data points a home needs helps you make the list first. If a laptop on a cable is slow right at the router, the cabling is not the problem, and an internet technician who finds where the speed goes is the right booking. On a fibre connection with a fast plan, the fibre upgrade page explains cabling the house from a switch beside the box.