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Numbers converter
Convert a number between bases — binary, octal, decimal, hex and anything up to base 36.
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How base conversion works
A base is just how many digits you count with before the column rolls over. Decimal uses ten (0–9), binary two (0 and 1), hexadecimal sixteen (0–9 then a–f). The number itself does not change — 255, FF and 11111111 are the same quantity written three ways.
The ones people actually use
| Base | Name | Digits | 255 looks like |
|---|---|---|---|
| 2 | Binary | 0 1 | 11111111 |
| 8 | Octal | 0 1 2 3 4 5 6 7 | 377 |
| 10 | Decimal | 0 1 2 3 4 5 6 7 8 9 | 255 |
| 16 | Hexadecimal | 0 1 2 3 4 5 6 7 8 9 a b c d e f | FF |
Where this breaks. A browser holds whole numbers exactly only up to 9,007,199,254,740,991. Past that the digits start drifting, so the converter says so rather than printing a confident wrong answer.