About this tool
Hexadecimal (base-16) uses the digits 0–9 and A–F, where each digit represents four bits. It's the compact notation for bytes, colors, memory addresses and hashes. Converting to decimal expands each hex digit by its place value — 0xFF is 15×16 + 15 = 255.
Paste a hex value, with or without the 0x prefix and in any case, and the decimal equivalent appears immediately. The tool ignores spaces between bytes and validates that only hex digits are present, flagging anything invalid before you rely on the result.
Conversion happens locally — values you paste never leave your browser.
Frequently asked questions
Does it need the 0x prefix?
No. The 0x prefix is optional and case doesn't matter — FF, ff and 0xFF all convert to 255. Spaces between bytes are ignored too.
How large a value can it convert?
Arbitrarily large — the converter uses arbitrary-precision integers, so long hashes and 64-bit-plus values convert exactly.
Can I convert decimal back to hex?
Yes — use the decimal to hex converter, which offers a 0x-prefix option, uppercase toggle and byte padding.