Decimal to Hex Converter

Decimal is base 10 and hexadecimal is base 16. The number is repeatedly divided by 16, and each remainder maps to a hex digit (0-9 then a-f), read from last to first.

Hex is a compact way to write binary. Two hex digits cover one byte, so it shows up in colors (#ff8800), memory addresses, byte dumps, hashes and machine code.

They mean the same value. ff and FF are equal. Lowercase is common in code and CSS, while uppercase often appears in hardware docs and hash output. Pick whatever your context expects.

0x marks a literal as hexadecimal in many languages, so 0xff is 255 in decimal. It is a notation hint, not part of the value, so you can turn it off if you only need the digits.

Yes. The converter uses arbitrary-precision integers, so even numbers far larger than 64 bits convert exactly with no rounding.

No. The conversion runs entirely in your browser, so the numbers you enter never leave your device.