Cat5e vs Cat6 vs Cat7 vs Cat8: Which Ethernet Cable to Buy
Quick answer
For most homes, Cat6 — it handles gigabit easily with headroom and costs little more than Cat5e. Cat5e still does 1 Gbps if it's already in the wall. Cat6a if you're wiring for 10 GbE. Skip Cat7 for home use, and Cat8 is for short data-centre runs, not living rooms.
The standards at a glance
| Cable | Rated speed | Bandwidth | Max at full speed | Home verdict |
|---|---|---|---|---|
| Cat5e | 1 Gbps | 100 MHz | 100 m | Fine for gigabit plans |
| Cat6 | 1 Gbps (10 Gbps to ~55 m) | 250 MHz | 100 m at 1 Gbps | The default buy |
| Cat6a | 10 Gbps | 500 MHz | 100 m | Future-proofing runs |
| Cat7 | 10 Gbps | 600 MHz | 100 m | Not a home standard — use Cat6a |
| Cat8 | 25–40 Gbps | 2000 MHz | 30 m | Data centres only |
These are the ratings the cable standards define — what a certified cable of that category is built to carry. A longer cable, a bad connector or a cheap counterfeit performs worse than its label promises.
Cat5e vs Cat6
Cat5e handles 1 Gbps at full 100-metre length — which still covers every internet plan most homes will buy this decade. Cat6 is built to tighter limits (250 MHz), which means less crosstalk and comfortable gigabit, plus 10 Gbps over short runs up to about 55 metres. In practice: if the price difference is small, buy Cat6; if Cat5e is already installed and your plan is gigabit or less, there's no reason to re-cable.
Cat7 — the odd one out
Cat7 is the one to be careful with. It's an ISO-standard cable (shielded, with specialized connectors) that was never adopted by the TIA standards that home and office wiring follows, so consumer "Cat7" cables are a mixed bag, and their connectors don't officially fit the 8P8C jacks on your router and PC. The capability Cat7 was reaching for arrived properly in Cat6a — 10 Gbps at full 100 m, with standard connectors. For home 10 GbE, buy Cat6a and skip the Cat7 confusion.
Cat8 and multi-gig
Cat8 doubles down: 25–40 Gbps, but only to 30 metres, with shielding everywhere. That's a data-centre patch-cable profile. Home multi-gig (2.5/5/10 GbE) runs happily on Cat6 (short runs) or Cat6a; buying Cat8 for a router-to-PC link gains you nothing except a stiffer, pricier cable.
What actually limits your speed
In most homes the Ethernet cable is the strongest link in the chain. The usual order of bottlenecks: the internet plan itself, then Wi-Fi conditions, then an old router — and only then the cable. A gigabit plan through Cat5e delivers gigabit; no cable upgrade raises the plan's number. Where cables do matter: long runs through walls (buy Cat6a once, forget it), and links between router, switch and a wired PC or console.
Buying tips
- Pure copper, not CCA. Copper-clad aluminium cable is cheaper, runs warmer and underperforms; listings that don't say pure/copper are suspect.
- Buy the length you need. Coiling a long spare cable behind the desk works, but a tidy right-length lead is easier to manage and avoids sharp kinks.
- Solid core for in-wall runs, stranded for patch leads that get flexed.
- Shielding (STP) only if you need it — near heavy power runs or in walls with lots of cable. Unshielded (UTP) is fine otherwise and easier to terminate.
- In-wall rating: look for the fire rating your local rules ask for — CM, CMR or CMP in the US, LSZH (low smoke zero halogen) sheathing in the UK and much of Europe.
After wiring, measure: run the speed test on the new cable and compare with Wi-Fi — you should see the plan's real top end on the wired side. The difference between the two is what your wireless was costing you; more on that in Wi-Fi vs Ethernet.