Number Base Converter

The Number Base Converter translates a value between binary (base 2), octal (base 8), decimal (base 10) and hexadecimal (base 16) all at the same time. Type a number into any one field and the other bases update simultaneously, so you can read every representation side by side and cross-check that a conversion is correct in a single glance.

It is a constant companion for programmers working with bit masks, colour codes, memory addresses, permissions and other low-level data, as well as for students learning how different number systems relate to one another. Seeing all four bases together turns a fiddly mental conversion into something you can simply read off the screen.

Everything is computed in the browser with no round trip to a server, so conversions are instant and completely private. There is no install and no account, which makes it easy to keep the tool open as a quick reference in a separate tab while you write or debug code.