Convert numbers between binary, octal, decimal, hexadecimal and any base from 2 to 36. Exact big-number support, prefixes like 0x and 0b, and batch conversion.
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How to use the Number Base Converter
Paste one number per line.
Choose the input base, or leave it on auto-detect for 0x, 0b and 0o prefixes.
Read or copy the binary, octal, decimal, hex and custom base values.
Why use this Number Base Converter
Exact big numbersUses arbitrary-precision integers, so huge values are never rounded.
Auto-detect prefixesUnderstands 0x, 0b and 0o as well as plain decimal.
Custom baseAdd any extra output base from 2 to 36.
Readable outputGroup binary in fours and hex in pairs.
Frequently asked questions
How do I convert binary to decimal?
Paste the binary number with input base Binary, or type it with a 0b prefix on auto-detect.
Does it handle negative numbers?
Yes. A leading minus sign is kept in every base.
What is the largest number it can convert?
There is no practical limit. Very long numbers are converted exactly.