About decimal and hex

Decimal is base 10 — ordinary numbers. Most code displays values in decimal even when they're stored as bits underneath, so it's usually one side of any base conversion.

Hexadecimal is base 16 — digits 0–9 then a–f. One hex digit is exactly four bits, so bytes read as tidy two-digit pairs. Colors, memory addresses, and hashes are all conventionally written in hex with a 0x prefix.

For example, decimal 1024 is 400 in hex. The converter uses BigInt, so numbers of any size convert without losing precision — and it all runs in your browser.