The Wiring Standard

T-568B Color Code

The T-568B standard defines the exact order of eight color-coded wires inside an RJ-45 connector. Memorize this sequence — it's the foundation of every cable you'll build.

The Standard

Why Standards Matter

The TIA/EIA-568-B standard ensures that every Ethernet cable, no matter who built it, connects the same pins on both ends. Without a universal standard, cables built by different technicians wouldn't be interchangeable. The T-568B variant is the most widely used in the United States and is the standard required for most IT certifications.

Reference

T-568B Pin Assignments

The diagram below shows the correct wire positions from the learner's perspective — with the connector tab facing down and Pin 1 on the left.

T-568B wire position reference showing 8 color-coded wires in an RJ-45 connector

T-568B reference: Pin 1 (White-Orange) through Pin 8 (Brown), viewed with the tab facing down.

📝 The Sequence

White-Orange · Orange · White-Green · Blue · White-Blue · Green · White-Brown · Brown
Notice the pattern: the stripe (white) wire always comes first in each pair — except for the Blue pair (Pins 4–5), where solid Blue comes before White-Blue.

🖨️ Job Aid

Print or screenshot the reference diagram above and keep it visible at your workstation while you work. On the job, technicians use a T-568B reference card as a quick-check tool — compare your wire arrangement against the card before inserting wires into the connector every time.

🎧 Listen: The T-568B Sequence

Audio walkthrough of the color sequence and how to remember it. (0:45)

🎯 Interactive Practice

Arrange the Wires

Drag each wire into the correct pin position. When you're ready, click Check My Work to see how you did.

Available Wires — drag to the connector below
RJ-45 Connector — Pin 1 (left) to Pin 8 (right)
Pin 1
Pin 2
Pin 3
Pin 4
Pin 5
Pin 6
Pin 7
Pin 8