Convert numbers between decimal, binary, hexadecimal, and octal. Instant conversion with copy support. Free developer tool. This tool runs entirely in your browser — no data is sent to any server. It's fast, free, and works on any device.
Number base conversion is fundamental to computing and digital electronics. While humans naturally think in base-10 (decimal), computers operate in base-2 (binary), and programmers frequently use base-16 (hexadecimal) as a compact representation of binary data. Octal (base-8) appears in Unix file permissions and some legacy systems. Understanding these conversions is essential for low-level programming, debugging memory addresses, working with color codes (#FF0000 is hex for red), and network configurations like IP addresses and subnet masks. This converter handles integers of arbitrary size and supports the four most common bases used in software development. All conversions happen locally in your browser with no data sent to any server.
Hexadecimal is a compact way to represent binary data — each hex digit maps to exactly 4 binary bits. So instead of writing 11111111 in binary, you write FF in hex. It's widely used for memory addresses, color codes, and byte values.
Binary (base-2) is the native language of computers. Every piece of data — text, images, programs — is ultimately stored as sequences of 0s and 1s. Understanding binary helps with bitwise operations, permissions, and hardware-level debugging.
Octal uses digits 0-7. It's most commonly seen in Unix file permissions: 755 means rwxr-xr-x. Each octal digit represents exactly 3 binary bits, making it a convenient shorthand.
Yes — this tool handles arbitrarily large integers using JavaScript's BigInt. There's no practical limit on the number of digits you can convert.
This converter works with unsigned (positive) integers. Signed numbers use one bit to represent positive/negative, which changes the binary representation. For signed conversion, you'd need a two's complement calculator.