Convert numbers between Binary, Octal, Decimal, and Hexadecimal.
Any base, any number
| Decimal | Binary | Octal | Hex |
|---|---|---|---|
| 0 | 0 | 0 | 0 |
| 1 | 1 | 1 | 1 |
| 2 | 10 | 2 | 2 |
| 4 | 100 | 4 | 4 |
| 8 | 1000 | 10 | 8 |
| 10 | 1010 | 12 | A |
| 15 | 1111 | 17 | F |
| 16 | 10000 | 20 | 10 |
| 255 | 11111111 | 377 | FF |
The Number Base Converter translates a number between binary, octal, decimal, and hexadecimal — showing all four bases at once, live, as you type into any of them. The math runs on BigInt, so values beyond 2^53 convert exactly, with none of the silent precision loss ordinary JavaScript-number converters suffer on long binary strings or large hex values. Each base is labelled with its conventional prefix (0b, 0o, 0x) and has its own copy button. Everything runs in your browser.
Effectively unlimited. The converter uses BigInt arithmetic rather than floating-point numbers, so it stays exact past 2^53 — the point where typical JavaScript converters silently round. Long binary strings, 64-bit values, and beyond convert digit-perfectly.
Binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16) — the four bases programmers actually use — with the standard 0b, 0o, and 0x prefixes shown so you can paste results straight into code.
Because different layers speak different bases: permissions and file modes are octal, memory addresses and colors are hex, bit flags and masks are binary, and humans think in decimal. Converting between them is a daily task in debugging, embedded work, and networking.
No. Conversion happens entirely in your browser as you type — nothing is uploaded, logged, or stored.