Base Converter
Convert integers between decimal, binary, hex, and octal. BigInt-backed.
published
- [FREE]
- [NO_SIGNUP]
- [NO_UPLOAD]
A base converter translates an integer between binary, octal, decimal, and hexadecimal. Used constantly in low-level code, embedded systems, debugging hex dumps, and reading hashes.
Conventional prefixes
| Base | Prefix | Chars |
|---|---|---|
| 2 | 0b | 0-1 |
| 8 | 0o | 0-7 |
| 10 | (none) | 0-9 |
| 16 | 0x | 0-9 a-f |
Why BigInt
JavaScript Number maxes at 2^53. Hex hashes, 64-bit memory addresses, and large signed integers exceed that. BigInt handles arbitrary size. The tool parses with BigInt and re-stringifies in the target base.
Related tools
- Bitwise calculator — for AND/OR/XOR/shifts (planned next).
- Hash Generator — hex digests of arbitrary text or files.
Frequently asked questions
Why BigInt?
JavaScript numbers lose precision above 2^53. BigInt handles arbitrary size — useful for 64-bit hardware values, hex hashes, and the kind of huge integers that show up in low-level code.
What input formats are accepted?
Plain digits for the chosen base, or with the conventional prefix: 0b (binary), 0o (octal), 0x (hex). Underscores are stripped, so 1_000 and 1111_1111 work. Leading minus for negatives.
Why does my hex have lowercase letters?
The output is normalized to lowercase a-f. Convert to uppercase after copying if you need it.
Can I convert decimals (with a fractional part)?
Not in this version — integers only. Fractional bases are a different problem (precision, repeating expansions). Use a math CAS like Wolfram Alpha for those.
Is the conversion private?
Yes. Pure JS BigInt math. No upload, no analytics on input.