Decimal to Binary Converter
Convert decimal numbers to binary representation online. Free, fast, and runs entirely in your browser.
Input
Output
What Is Decimal to Binary Conversion?
Decimal to binary conversion transforms numbers from the base-10 (decimal) numeral system into the <a href="https://en.wikipedia.org/wiki/Binary_number" target="_blank" rel="noopener">base-2 (binary) numeral system</a>. Binary uses only two digits, 0 and 1, to represent all values. Each position in a binary number represents a power of 2, just as each position in a decimal number represents a power of 10.
Binary numbers are fundamental to computer science and digital electronics. All data in computers is ultimately stored and processed as binary values. Learn the fundamentals with this <a href="https://www.khanacademy.org/computing/computers-and-internet/xcae6f4a7ff015e7d:digital-information/xcae6f4a7ff015e7d:binary-numbers/v/the-binary-number-system" target="_blank" rel="noopener">Khan Academy binary lesson</a>. This tool converts decimal integers to their binary equivalents 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. You can also click Sample to load example values, or Upload a text file.
View Binary Output
The right panel updates automatically with the binary representation of each decimal number. Negative numbers are prefixed with a minus sign.
Copy or Download
Click Copy to copy the binary output to your clipboard, or Download to save it as a text file.
Conversion Examples
Here are some common decimal to binary conversions:
Decimal Input
Binary Output
Frequently Asked Questions
How does decimal to binary conversion work?
The conversion works by repeatedly dividing the decimal number by 2 and recording the remainders. The binary representation is the sequence of remainders read in reverse order. For example, 42 divided by 2 gives remainders 0, 1, 0, 1, 0, 1 — reversed: 101010.
Can this tool handle large numbers?
Yes. The tool uses JavaScript BigInt internally, so it can convert arbitrarily large integers without losing precision.
Is my data sent to a server?
No. All processing happens locally in your browser. No data leaves your machine.
Does it support negative numbers?
Yes. Negative decimal numbers produce a binary result prefixed with a minus sign (e.g., -42 becomes -101010). You can verify results using a decimal to binary reference table.
Related Tools
Learn more: IEEE 754 floating-point standard, Electronics Tutorials on binary conversion, and the MDN parseInt documentation.