Number Base Converter
Convert integers between binary, octal, decimal and hex.
About Number Base Converter
The Number Base Converter translates integers between binary, octal, decimal and hexadecimal simultaneously — enter a value in any base and read it in all the others. Testers meet base conversions in permission masks, HTTP/2 frame dumps, color values, bit flags, error codes and memory addresses.
Conversion is instant and exact for whole numbers, and having all four representations visible at once makes it easy to sanity-check bit patterns or spot an off-by-one in a flag value.
How to use
- Enter your number in the "Value" field.
- Select which base the input is in under "Input base" (binary, octal, decimal or hex).
- Read the converted value in every other base — the results update as you type.
Frequently asked questions
Why do testers care about hex and binary?
Bit flags and permission masks only make sense in binary, IDs and hashes are usually shown in hex, and Unix file permissions are octal. Converting to decimal is often the quickest way to verify what a value "really" is.
Are negative or fractional numbers supported?
The converter works with whole numbers, which covers the flags, masks, codes and addresses that come up in practice. Fractional base conversion is a different (and rarer) problem.
What do the 0x, 0o and 0b prefixes mean?
They are conventional markers for hexadecimal, octal and binary respectively — 0xFF, 0o777 and 0b1010 in most languages. Enter the digits here and choose the matching input base.
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