Number Base Converter
Convert between binary, octal, decimal, hexadecimal and any base from 2 to 36 — live, in both directions, with exact big-integer math for 64-bit and larger values.
About the number base converter
Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36, all at once. Type into any field and the rest update live. Bytewrench uses big-integer math, so even 64-bit values convert exactly without floating-point rounding, and negative numbers are supported.
A representation panel shows the bit length, byte count and prefixed forms (0x, 0o, 0b), making it handy for low-level debugging, bit-masking and working with colors or permissions.
Binary, octal, decimal, hex plus a custom base (2–36) stay in sync as you type.
Exact conversion for 64-bit and larger values — no floating-point errors.
See the bit length, byte count and 0x/0o/0b prefixed forms.
One click copies any representation to the clipboard.
Frequently asked questions
Does it handle 64-bit and larger numbers?
Yes. It uses big-integer arithmetic, so very large values convert exactly without the rounding errors you'd get from normal JavaScript numbers.
What bases are supported?
The fixed binary, octal, decimal and hexadecimal fields, plus a custom base selector for anything from 2 to 36 (using digits 0-9 and letters a-z).
Can I paste values with 0x or 0b prefixes?
Yes. Common prefixes (0x for hex, 0o for octal, 0b for binary) are recognized and stripped automatically.
Is anything sent to a server?
No. All conversion happens locally in your browser.