Decimal to Hex Converter

Decimal is base 10 and hexadecimal is base 16. The number is repeatedly divided by 16, and each remainder becomes a hex digit from 0-9 then a-f, read from the last remainder to the first. So 255 divides into 15 remainder 15, which reads as ff.

Hex is a compact way to write binary because two hex digits cover exactly one byte. You see it in web colors like #ff8800, memory addresses, byte dumps, hashes and machine code, where long strings of bits would be hard to read.

Yes. Any spaces and commas are removed before conversion, so 1,000,000 and 1 000 000 both convert to f4240. This lets you paste grouped numbers straight from a spreadsheet or document without editing them first.

They represent 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. The Uppercase toggle only changes the letters A to F, never the digits.

0x marks a literal as hexadecimal in many programming languages, so 0xff is 255 in decimal. It is a notation hint rather than part of the value, so you can leave it off when you only need the bare digits.

Yes. The converter uses arbitrary-precision integers, so numbers far beyond 64 bits convert exactly with no rounding or overflow. The output simply grows as long as it needs to be.

No. It handles non-negative whole numbers only. A minus sign, a decimal point or any non-digit character after stripping commas and spaces produces an Invalid number message.

Empty input returns an empty result rather than an error, so the output simply blanks out until you type a valid number again.

No. The conversion runs entirely in your browser, so the numbers you enter never leave your device. To go the other way, use the hex to decimal tool, or convert to base 2 with decimal to binary.