Base conversion and arithmetic
Bits (click to flip)
Subnet calculator
Units and transfer time
Unix time
Encode, hash and UUID
For iPhone, iPad and Mac
The app works offline and adds:
- Select text anywhere and convert it from the share sheet (hex, IP, Unix time, Base64)
- A Unix time widget
- A conversion quiz and lessons on two's complement and subnets
- CAN ID (J1939) decoding
Hex and binary
One hex digit is exactly 4 bits: 0xA5 is 1010 0101. Split a binary number into groups of four from the right and each group is one hex digit.
Two's complement
In signed integers the top bit is the sign. -n is stored as "flip every bit of n, then add 1", so -5 in 8 bits is 1111 1011 (0xFB).