Binary / Hex / Decimal Converter
Convert whole numbers exactly between bases 2–36.
Input & settings
Result
How to use it
- 1Pick the bases
Set the base your number is written in, and the base you want it in. Anything from 2 to 36 works.
- 2Paste the number
Digits only: no 0x or 0b prefix, no spaces, no decimal point. A leading minus sign is fine.
- 3Convert and copy
Press Convert, then copy the result or download it as a text file.
Good to know
Exact, not rounded
Conversion uses BigInt arithmetic, so even very long numbers keep every digit. Nothing is converted through floating point.
Bases 2 to 36
Digits run 0–9 then A–Z, so base 16 is hex, base 36 uses the whole alphabet. Letters are not case sensitive.
Whole numbers only
Fractions, exponents and digit separators are rejected rather than silently rounded.
Up to 10,000 digits
Longer input is refused so the page stays responsive.
Common uses
- Reading a hex colour or byte value as decimal
- Checking a binary mask from a datasheet
- Turning a decimal ID into base 36 for a short code
- Comparing octal file permissions with their binary bits
- Verifying a hash fragment copied from a log
Questions
How do I convert hex to decimal?
Set the input base to 16, the output base to 10, paste the hex digits without a 0x prefix and press Convert.
Does it handle negative numbers?
Yes. Start the number with a minus sign; the sign is kept in the result.
Why was my input rejected?
Every digit must be valid for the input base, so 9 is not allowed in binary and a decimal point is never allowed. Remove prefixes, spaces and separators first.
Is my number sent anywhere?
No. The conversion runs in your browser, and nothing is uploaded or stored.
How it works
Uses BigInt for exact integer conversion. Supports negative numbers and bases 2–36 (digits 0–9 and A–Z). Enter digits without 0x / 0b prefixes, spaces, fractions or separators. Up to 10,000 input digits.