Decimal to Hex Converter
Convert decimal numbers to hexadecimal representation online. Free, fast, and runs entirely in your browser.
Input
Output
What Is Decimal to Hexadecimal Conversion?
Decimal to <a href="https://en.wikipedia.org/wiki/Hexadecimal" target="_blank" rel="noopener">hexadecimal</a> conversion transforms numbers from the base-10 (decimal) numeral system into the base-16 (hexadecimal) numeral system. Hexadecimal uses digits 0-9 and letters A-F to represent values 0-15. It is widely used in computing because each hex digit maps directly to four binary bits.
Hexadecimal is essential in web development (CSS colors like #FF5733 -- see this <a href="https://css-tricks.com/nerds-guide-color-web/" target="_blank" rel="noopener">guide to hex colors on the web</a>), memory addresses, MAC addresses, and low-level programming. This tool converts decimal integers to uppercase hexadecimal instantly, supporting multiple values at once.
How to Use This Tool
Enter Decimal Numbers
Type or paste one decimal number per line in the left editor. Click Sample to load examples, or Upload a text file.
View Hexadecimal Output
The right panel updates automatically with the hexadecimal representation of each decimal number. Output uses uppercase letters (A-F).
Copy or Download
Click Copy to copy the hex output to your clipboard, or Download to save it as a text file.
Conversion Examples
Here are some common decimal to hexadecimal conversions:
Decimal Input
Hexadecimal Output
Frequently Asked Questions
How does decimal to hexadecimal conversion work?
Repeatedly divide the decimal number by 16 and record the remainders. Each remainder (0-15) maps to a hex digit (0-9, A-F). Read the remainders in reverse to get the hex value. For example, 255 = 15×16 + 15, so the hex is FF.
Why is the output in uppercase?
Uppercase hex (A-F) is the most common convention in programming and documentation. Both FF and ff represent the same value. You can also use Number.toString(16) in JavaScript to perform this conversion programmatically.
Is my data sent to a server?
No. All processing happens locally in your browser. No data leaves your machine.
Can it handle large numbers?
Yes. The tool uses JavaScript BigInt internally, so it can convert arbitrarily large integers without precision loss. Hex values are commonly used in HTML color codes and many other contexts.
Related Tools
Learn more: W3C CSS Color specification, ASCII code chart, and the MDN Number.toString documentation.