Convert decimal numbers to hexadecimal (base-16) notation. Outputs uppercase or lowercase hex with optional 0x prefix. Useful for colour codes, memory addresses, and byte values.
Key Features
Converts decimal integers to clean hexadecimal notation (base-16)
Configurable output casing (uppercase 0xFF or lowercase 0xff)
Optional "0x" prefix or "#" symbol for web color formatting
Zero-padding options for byte (2-digit), word (4-digit), and dword (8-digit) output
How to Use
Enter the decimal number you want to convert.
Choose your letter casing preference (uppercase or lowercase).
Select whether to include a "0x" prefix or leading zero padding.
Click "Convert to Hex" to view the hexadecimal result.
Copy the resulting hex string to your clipboard.
Example
Sample input
255
Sample output
FF
Edge Cases
Lowercase vs uppercase output
Zero as 0
Values larger than 0xFFFFFFFF
Frequently Asked Questions
Why does hexadecimal use letters A through F?
Hexadecimal is a base-16 numbering system. After digits 0 through 9, the letters A, B, C, D, E, and F represent numerical values 10 through 15.
Can this tool help convert RGB decimal values to hex colors?
Yes. By converting individual R, G, and B channel values (0-255) with 2-digit padding, you can assemble 6-digit hex color codes.
Does this support large numbers beyond 32 bits?
Yes. The converter handles arbitrary-precision BigInt decimals, allowing conversion of 64-bit, 128-bit, and larger numbers without overflow.
Privacy notice: when you run this tool, your input is sent over HTTPS to our server, processed in memory and returned. It is not stored or logged. Avoid pasting live secrets such as private keys or passwords.