I Could Not Remember My Binary Logic Gates in a Coding Interview — So I Built a Visual Reference

AND, OR, NOT, NAND, NOR, XOR, XNOR. Seven gates. Three basic truth tables. And yet, in the middle of a whiteboard interview, I blanked on whether NAND was "NOT AND" or "negative AND."

The interviewer was patient. I was not. I went home and built something that would make sure this never happened again.

The Problem: Gates Are Memorized, Not Understood

Every CS student memorizes the truth tables:

AND: 1 & 1 = 1, everything else = 0
OR:  0 | 0 = 0, everything else = 1  
XOR: different inputs = 1, same = 0

But memorization breaks under pressure. What you actually need is a visual intuition — seeing the bits aligned, watching which positions change, understanding what each gate does to the binary representation.

What I Built

bintranslate.com/binary-logic-gates is a free interactive binary logic gate reference. Pick any two binary numbers, and it shows you:

• All 7 gates applied simultaneously with results displayed in both binary and decimal
• Bit-by-bit alignment so you can see exactly which bit positions changed
• Interactive inputs — type any binary or decimal numbers and see results update in real time
• Truth table reference for quick lookup

No signup. No ads. Just gates.

Why Visual Beats Memorization

Here is what I mean. Take 5 (0101) and 3 (0011):

  0101  (5)
& 0011  (3)
= 0001  (1)

  0101  (5)  
| 0011  (3)
= 0111  (7)

  0101  (5)
^ 0011  (3)  
= 0110  (6)

When you see the bits stacked like this, the pattern becomes obvious. AND only keeps bits where both inputs have a 1. OR keeps bits where either input has a 1. XOR flips bits where inputs differ. After 5 minutes of playing with the tool, you stop memorizing and start understanding.

When You Actually Need Logic Gates

Beyond interview prep, binary logic gates show up in:

• Bitmasking — setting, clearing, or toggling specific bits in a register
• Permission systems — Unix file permissions (rwx = 7 = 111 in binary)
• Color manipulation — extracting R, G, B channels from a hex color
• Network subnetting — calculating network addresses with bitwise AND
• Hardware description — every digital circuit is built from NAND gates

The interactive reference at bintranslate.com/binary-logic-gates covers all of these with examples. If you are cramming for an interview or debugging some low-level code, it saves you from having to mentally reconstruct truth tables every time.