Ethernet cable Cat5e vs Cat6 vs Cat6a vs Cat8: which do you need at home?
The shop has Ethernet cables from Cat5e to Cat8, and the higher numbers cost more and promise 40 Gbps. Your internet plan is probably under 1 Gbps. Here is what the categories really mean and which one makes a difference.
The categories in one table
| Category | Rated bandwidth | Speeds it is made for | Good for at home? |
|---|---|---|---|
| Cat5 (no "e") | 100 MHz | 100 Mbps | Replace it: it often stops at 100 Mbps |
| Cat5e | 100 MHz | 1 Gbps at 100 m, usually 2.5 Gbps | Yes, for any plan up to 1 Gbps |
| Cat6 | 250 MHz | 1 Gbps at 100 m, 10 Gbps on short runs (about 37 to 55 m) | Yes, the usual safe buy |
| Cat6a | 500 MHz | 10 Gbps at 100 m | For cabling in walls, or a 10 Gbps home network |
| Cat7 / Cat7a | 600 / 1,000 MHz | An international class meant for different plugs | No benefit with RJ45 plugs; treat as Cat6a |
| Cat8 | 2,000 MHz | 25 to 40 Gbps up to 30 m, between data-centre switches | No: costly, stiff, no home device uses it |
The category is printed along the cable's outer jacket, for example CAT6 UTP 24AWG. If there is no print at all, assume the worst.
Why a better cable rarely makes the internet faster
Your internet speed is set by your plan and your line. A 500 Mbps plan uses half of what a 1 Gbps Cat5e link can carry, so swapping it for Cat8 changes nothing a speed test can see. What a cable does fix is everything Wi-Fi adds: weak signal, interference, airtime sharing and the retries that cause lag spikes. That is why "use a cable" is the first fix in good ping, jitter and packet loss. Faster categories only matter for traffic inside your home, such as copying big files to a network drive with 2.5 or 10 Gbps ports.
Want the numbers? 1 Gbps is about 119 MiB/s, which you can check (and turn into download times) in the unit converter's data-rate mode.
Showing 100 Mbps instead of 1 Gbps?
Gigabit Ethernet needs all four pairs of wires in the cable; 100 Mbps only needs two. So when one wire is broken, a plug is badly crimped or a cheap cable has only two pairs, the devices quietly agree on 100 Mbps and the internet feels capped at about 94 Mbps. Check the link speed:
- Windows: Settings → Network & internet → Ethernet shows Link speed, or in PowerShell run
Get-NetAdapter | Select Name, LinkSpeed. - Mac: hold Option, click the Apple menu → System Information → Network, or run
ifconfig en0 | grep media(the adapter may been1or higher). - Linux:
ethtool eth0 | grep Speed(use the name fromip link).
If it says 100 Mbps: try a different cable first, then a different port on the router or switch, and check for a sharp bend, a crushed spot under a door, or a plug whose little clip has snapped. Old Cat5 cables and some flat or very thin cables are the usual suspects.
Cables to avoid
- CCA (copper-clad aluminium): aluminium wires with a copper coating. They break more easily, are not standards-compliant, and run hot with Power over Ethernet. Look for pure copper or solid/stranded bare copper.
- Very cheap "Cat7" or "Cat8" patch leads with no brand: the category is often only on the packaging.
- Flat cables are fine for short runs under a carpet edge or a door, but they have less shielding and twisting, so prefer round cable for long runs.
Shielded or unshielded?
At home, unshielded (UTP) Cat6 is normal and fine. Shielded cable (FTP, STP) helps next to strong electrical noise, but only works properly if the shield is earthed through shielded sockets at both ends, which most home routers don't have.
Related
Stuck at 94 Mb/s on a speed test? · Run a cable without drilling holes · PS5 or Xbox downloads slow · NAT type strict or moderate: how to get Open · How much upload speed do video calls need? · Internet lags when someone downloads (bufferbloat) · Double NAT and CGNAT: port forwarding not working · Mbps vs MB/s: internet speed explained
Questions
Is Cat5e good enough for gigabit internet?
Yes. Cat5e is rated for 1 Gbps over 100 metres, and it usually carries 2.5 Gbps too.
Is Cat6 better than Cat5e for gaming?
Not noticeably. Both are far faster than any game needs. A cable of either kind beats Wi-Fi for ping and lag spikes.
Is Cat8 worth it for home?
No. Cat8 is designed for 25 to 40 Gbps links of up to 30 metres between data-centre switches. No home router or console uses those speeds.
Why does my Ethernet only show 100 Mbps?
Usually a broken wire, a bad plug, or an old Cat5 cable, because gigabit needs all four wire pairs. Try another cable and another port.
What is the difference between Cat6 and Cat6a?
Cat6a is rated for 10 Gbps over the full 100 metres; Cat6 only manages 10 Gbps on shorter runs. Both do 1 Gbps at 100 metres.
Published · updated .