How it works
This random binary generator draws one of the 256 bytes, all equally likely, and writes it in two groups of four, such as 1011 0010. Tap 16 bits or 24 bits for a longer number. Copy joins the bits: 10110010.
Read the full guide
How to read a byte
Say the result is 1011 0010. Each place in a byte is worth double the one to its right: 128, 64, 32, 16, 8, 4, 2, 1. Add up the places that hold a 1: 128 + 32 + 16 + 2 = 178. For hex, take each group of four alone. 1011 is 11, which hex writes as B, and 0010 is 2, so the byte is B2.
Practice: convert first, then check
Cover the lines under the result, convert the byte on paper, then look. The table below the tool lists all 256 bytes in order, each with its sum, so you can work backwards: pick a decimal number, write it in binary and find its row. Rows 32 to 126 also name their ASCII character.
- Four 1s is the most common count: 70 of the 256 bytes have it. Only one byte is all 0s and one all 1s.
- Capital A is 0100 0001 and small a is 0110 0001. Only the 32 place differs, and the same goes for every letter in ASCII.
Questions and answers
Are the bits really random?
The page draws one number from 0 to 255, each equally likely, and writes it in binary. That equals a fair coin flip for each bit, so 1111 0000 is as likely as any byte. Fine for lessons and test data, not passwords or keys.
How do I get a random letter in binary?
Tap ASCII text, 32 to 126. Every result is then one of the 95 printable ASCII codes, and the line under it names the character: 0100 0001 is capital letter A. For a five-character string, set How many to 5 first, then tap it.
Can I get a binary number longer than 8 bits?
Yes. Tap 16 bits, where the left place is worth 32,768 and the largest value is 65,535, or 24 bits, which reach 16,777,215. For 32 bits, set How many to 4, then tap 8 bits and read the four bytes in order.