tools / Reverse Engineering & CTF
Number Base Converter (hex, dec, binary)
Type a number in any base (prefix it with 0x, 0b or 0o) and read it back in decimal, hex, octal and binary, plus the signed two's complement for a chosen bit width and the byte-swapped value. The small conversions that come up all through RE and exploit work.
37359285590xdeadbeef0o336533373570b11011110101011011011111011101111-5590387370xefbeaddeHow it works
Two's complement
For a given bit width, the top bit is the sign. This shows both the raw unsigned value and how it reads as a signed integer, which is where off-by-one and negative-length bugs hide.
Byte swap
The endian flip reverses the byte order for the selected width, so you can turn a big-endian value into the little-endian bytes that x86 actually stores.
FAQ
How do I read a negative number in hex?
Enter it as decimal (like -1), pick the bit width, and the two's complement output shows the hex the machine stores (0xff for -1 at 8 bits).
