Base Converter
Online converter for binary, octal, decimal, hexadecimal and any base 2-36, using BigInt to support very large integers.
How to Use & FAQ
Base Converter
Online converter for binary, octal, decimal, hexadecimal and any base 2-36, using BigInt to support very large integers.
How to Use
- Choose the input baseChoose binary/octal/decimal/hexadecimal, or a custom base from 2 to 36.
- Enter a valueEnter the integer to convert; very large integers and minus signs are supported.
- Click "Convert"View the results in each base; you can also specify an extra output base.
- Copy the resultCommon uses: turn a decimal port into hex for debugging, or a binary mask into decimal to verify.
- Handling very long integersWhen a plain number would overflow, paste the value as a string; this tool parses it exactly as BigInt.
Related tools
Related reading
FAQ
How large a number is supported?
It is built on BigInt, so it supports integers of arbitrary length, beyond the JavaScript safe-integer range (2^53). Even very long decimal strings convert exactly, without the distortion plain numbers would show.
Can it convert decimals (fractions)?
It currently supports integers; for fractional values, scale them up to integers first (e.g. treat 0.5 as 5 in base 10, then divide by 10). For decimal precision, use a dedicated calculator.
Which bases are supported?
It supports base 2 through 36, covering binary/octal/decimal/hexadecimal, plus custom bases represented with 0-9 and a-z (e.g. base 32 is common in short links).
Are negative numbers supported?
Integers with a leading minus sign are supported; decimals (fractions) are not, so scale them up to integers first. The sign is preserved across all bases.
Why do letters beyond f appear?
Hexadecimal only uses 0-9 and a-f; above base 16 the letters g-z are used for larger values, up to base 36 (using all of 0-9 and a-z).
Will the conversion lose precision?
No. It relies on BigInt integer arithmetic and does not use floating point, so even very long integers convert exactly — none of the 0.1+0.2≠0.3 problems.
Is a hex color code the same as base conversion here?
The principle is the same but the use differs: in #RRGGBB, three decimal 0-255 values are each written as two hex digits and concatenated. For colors use the dedicated color tool; this one is better for pure numeric values.
Why does my binary string have many leading zeros?
Binary uses only 0/1 per digit, so the same number is very long in binary; leading zeros are usually padding to byte-aligned lengths like 8/16/32 bits and do not change the value.