Pixel Art & Secret Messages

Paint colorful pixel art and then see the numbers hiding inside. Encode words as numbers and decode secret messages -- just like computers do!

Choose a mode

Pixel Art

Pick a color

Click cells to paint, then tap "Show Data" to see the numbers

Letter Numbers

Every letter has a secret number code. Computers use numbers like this to store text.

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Letter Codes

A=1
B=2
C=3
D=4
E=5
F=6
G=7
H=8
I=9
J=10
K=11
L=12
M=13
N=14
O=15
P=16
Q=17
R=18
S=19
T=20
U=21
V=22
W=23
X=24
Y=25
Z=26

How Computers Store Data

Images as Numbers

Every digital image is a grid of tiny colored squares called pixels. Each pixel is stored as a number that represents its color.

  • A simple 8x8 grid stores 64 numbers
  • A phone photo might have millions of pixels
  • Higher numbers = more colors = better quality
  • This is called a bitmap or raster image

Text as Numbers

Computers cannot store letters directly -- they only know numbers. So every letter gets a number code.

  • A=1, B=2, C=3 ... Z=26 (simple cipher)
  • Real computers use ASCII (A=65) or Unicode
  • The word "CAT" is stored as three numbers: 3, 1, 20
  • Every emoji, symbol, and character has a number too

The Caesar Cipher

Julius Caesar sent secret messages by shifting every letter forward by 3 places. A became D, B became E, and so on.

  • Shift 3: CAT (3,1,20) becomes FDW (6,4,23)
  • The receiver subtracts 3 from each number to decode
  • When a number goes past 26, it wraps back to 1
  • This is one of the oldest known encryption methods

Data Is Everywhere

Inside a computer, everything is stored as numbers -- even sounds and videos.

  • Photos = grids of color numbers (pixels)
  • Music = thousands of sound level numbers per second
  • Video = many images (frames) played quickly
  • All numbers are stored in binary (0s and 1s)