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Base converter

255 is binary 11111111, octal 377, and hex FF. The range runs from 0 up to, but not including, 2 to the 64th. The numbers stay in this browser.

Why this exists

The FF in a color code and the FF on this page are two ways to write the number 255.

A URL’s %FF and this base conversion are different jobs. This page converts one whole number among four bases.

  1. 01How to use it

    Type the number you know into binary, octal, decimal, or hex.

    The other fields and the result below become the same number. Copy puts the four lines on the clipboard.

    Clearing a field clears the others. Closing the tab clears the numbers.

  2. 02What you get

    255, FF, 0xFF, 11111111, and 377 are all 255.

    10, 0b1010, 12, and A are all 10. 0 stays 0 in every field.

    The largest 64-bit value is 18446744073709551615, sixty-four 1 digits in binary, and hex FFFFFFFFFFFFFFFF.

    Entered255

    255 11111111 · 377 · FF
    10 1010 · 12 · A
    0xFF 255
    largest 64-bit FFFFFFFFFFFFFFFF

  3. 03Worth knowing

    A 2 in binary, an 8 or 9 in octal, an A in decimal, or a G in hex stops.

    Negatives and decimal points are not read. This page is whole numbers from 0 up.

    Leading zeros stay in the field you typed and the other fields use the short form.

    This conversion is not a cipher. It writes the same number with different digits.

Questions

QWhat is 255 in hex?
AIt is FF. Binary is 11111111 and octal is 377.
QIs 0xFF read?
AYes in the hex field. 0x in the decimal field stops.
QAre negatives read?
ANo. Only whole numbers from 0 are read, and 2 to the 64th stops.
QAre the numbers saved?
ANo. They stay in this browser and are not sent to a server.

How this page works it out

This page converts one whole number among binary, octal, decimal, and hexadecimal. 255 is 11111111, 377, 255, and FF. 10 is 1010, 12, and A. 0 stays 0 in every field.

The range runs from 0 up to, but not including, 2 to the 64th. 18446744073709551615 is hex FFFFFFFFFFFFFFFF and sixty-four 1 digits in binary. Anything larger stops. Spaces and underscores are removed. A leading 0x is removed only in hex, 0b only in binary, and 0o only in octal. The other fields use the short form without leading zeros, and hex is uppercase.

A 2 in binary, an 8 or 9 in octal, an A in decimal, a G in hex, a negative, or a decimal point is not read. This rule is separate from Base64. The numbers stay in this browser and are not sent to a server.

  • # binary
  • # hex
  • # decimal
  • # octal