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Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal — or any base from 2 to 36. Put one number per line to convert a list, and numbers of any size are exact, not rounded.
How to Convert Between Binary, Decimal and Hex
- Enter the numbers
Type or paste one number per line. Prefixes such as0x,0band0oare understood when the input base is set to Detect. - Choose the bases
Pick the base of your numbers and the base you want, or All to see binary, octal, decimal and hex side by side. - Copy the result
Each line of the result matches a line of your input. Copy it or download it as a .txt file.
Example
255 0x1F4 0b101010
255 → bin 11111111 · oct 377 · dec 255 · hex FF
Frequently Asked Questions
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How do I convert binary to decimal?Each binary digit is worth twice the one to its right: 1, 2, 4, 8, 16 and so on. Add up the values where there is a 1 —
101010is 32 + 8 + 2 = 42. Paste the binary number here with the input base set to Binary or Detect. -
How do I convert decimal to hex?Divide by 16 repeatedly and write down the remainders from last to first, using A–F for 10–15: 255 is 15 × 16 + 15, so it is
FF. The converter does this for numbers of any size. -
Are negative numbers and very large numbers supported?Yes. A minus sign is kept, and numbers are converted exactly with arbitrary precision, so a 64-bit or 128-bit value does not lose digits. Fractions are not supported.
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What does base 36 mean?A base uses that many digits. Base 36 uses 0–9 and then A–Z, which makes it handy for short IDs. Any base from 2 to 36 can be chosen here.
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Is anything sent to a server?No. The conversion runs in your browser.