All four bases, synced live
Type into any field — binary, octal, decimal, or hex — and the other three update instantly. Negative numbers and huge values work, so it's equally useful for checking a permission mask or converting a cryptographic hash.
Frequently asked questions
How big a number can I convert?
Arbitrarily large — conversion uses big-integer math, so 256-bit hashes and beyond convert exactly with no precision loss.
Can I paste values with prefixes like 0x?
Yes — 0x, 0b, and 0o prefixes are recognized and stripped, as are underscores and spaces used as digit separators.
Why do programmers use hex and binary?
Binary is what hardware actually stores; hex packs four binary digits into one character, making it the compact standard for memory addresses, color codes, and byte values.