Need T568A vs T568B without squinting at a static chart? Toggle the standard above, pick straight-through or crossover, and copy the wire order. This RJ45 pinout is part of the networking tools on TechOpt.io. The crimp steps live in How to Make Ethernet Cables.
RJ45 pinout: T568A vs T568B
Both standards are eight wires in four twisted pairs, as described on the TIA/EIA-568 pinout. The only difference is which pair sits on pins 1 and 2. T568B (the usual choice in North America) puts the orange pair there. T568A puts the green pair there. Blue stays on 4–5 and brown stays on 7–8 either way. Use the same standard on both ends of a straight-through cable.
Straight-through vs crossover
A straight-through cable is T568A or T568B on both plugs. That is what you want for almost every patch cable: PC to switch, AP to switch, patch panel to jack. A crossover uses T568A on one end and T568B on the other, which swaps all four pairs (the 1000BASE-T crossover). Modern NICs and switches do Auto-MDIX, so you almost never need to crimp a crossover today.
How to read the plug
Look down on the plug with the clip underneath and the cable toward you. The gold contacts are the small end, away from the cable. Pin 1 is on the left and pin 8 is on the right — the same view as the diagram above. Cat5e, Cat6, and Cat6a share this pinout; category changes twist rate and bandwidth, not the color order.
T568A and T568B color order
| Pin | Pair | T568A | T568B |
|---|---|---|---|
| 1 | 1–2 | White/Green | White/Orange |
| 2 | 1–2 | Green | Orange |
| 3 | 3–6 | White/Orange | White/Green |
| 4 | 4–5 | Blue | Blue |
| 5 | 4–5 | White/Blue | White/Blue |
| 6 | 3–6 | Orange | Green |
| 7 | 7–8 | White/Brown | White/Brown |
| 8 | 7–8 | Brown | Brown |
FAQ
What is the difference between T568A and T568B?
Only the orange and green pairs swap. T568B puts white/orange and orange on pins 1 and 2; T568A puts white/green and green there. Blue is always pins 4–5 and brown is always 7–8. A straight-through cable uses the same standard on both ends.
Should I use T568A or T568B?
Use T568B unless a spec or the other end of an existing run already uses T568A. T568B is the usual choice in North America. Mixing A and B on one cable makes a crossover.
What is a straight-through vs crossover cable?
Straight-through uses the same T568A or T568B order on both ends, which is what you want for almost every patch cable today. A crossover uses T568A on one end and T568B on the other so all four pairs swap. Gigabit Ethernet and Auto-MDIX mean you almost never need a crossover anymore.
Which way do I hold the RJ45 plug when lining up the wires?
Look down on the plug with the clip underneath and the cable toward you. The gold contacts are the small end, away from the cable. Pin 1 is on the left and pin 8 is on the right. That is the view in the diagram above.
Is the Cat6 pinout the same as Cat5e?
Yes. Cat5e, Cat6, and Cat6a all use the same T568A and T568B eight-wire order. Category changes twist rate, bandwidth, and connector rating, not the color sequence.
Does this RJ45 pinout tool upload anything?
No. It runs entirely in your browser. The standard and cable type never leave your machine.
Looking for more networking how-tos? Browse the servers and networking guides or the rest of the tools.