Number Base Converter
Convert numbers between decimal, binary, hexadecimal, and octal bases instantly. Free, private, browser-based.
Decimal (Base 10) INPUT
255
Binary (Base 2)
11111111
Octal (Base 8)
377
Hexadecimal (Base 16)
FF
How to Use
- 1. Select the base of your input number — Decimal, Binary, Octal, or Hexadecimal.
- 2. Type your number in the input field. Results update instantly.
- 3. The INPUT badge marks which row is your entered value — the other three are the converted outputs.
- 4. Click Copy next to any result to copy it to the clipboard.
- 5. Click Clear inside the input to reset and start over.
About This Tool
In computing, numbers can be represented in different bases (radixes). Understanding these bases is essential for developers working with low-level programming, bit manipulation, memory addressing, and network protocols.
Decimal (base 10) is what we use in everyday life with digits 0–9. Binary (base 2) is the foundation of all computing, using only 0 and 1 to represent the on/off states of transistors. Octal (base 8) uses digits 0–7 and is still used in Unix file permissions. Hexadecimal (base 16) uses digits 0–9 and A–F, and is widely used in programming for memory addresses, color codes, byte values, and cryptographic hashes.
This tool uses JavaScript's native parseInt(value, fromBase) and number.toString(toBase) functions for accurate conversion. All computation happens in your browser — no data is sent anywhere.
You may also find our Text to Binary and Hash Generator helpful.
Frequently Asked Questions
What is a number base (radix)?
A number base or radix is the number of unique digits used in a positional numeral system. Decimal uses 10 digits (0–9), binary uses 2 (0, 1), octal uses 8 (0–7), and hexadecimal uses 16 (0–9, A–F).
Why is binary important in computing?
Computers process information using transistors that have two states (on/off), which maps to binary (0 and 1). All data — text, images, programs — is ultimately stored and manipulated as binary.
What is hexadecimal used for?
Hexadecimal (hex) is widely used in programming because it compactly represents binary: 1 hex digit = 4 binary digits. It's used for memory addresses, color codes (#FF5733), and byte values.
What is octal used for?
Octal was historically used in computing because older machines had word sizes divisible by 3. Today it's mainly used in Unix/Linux file permissions (e.g., chmod 755).
Can this tool convert negative numbers?
Currently the tool converts non-negative integers. Negative number representation (two's complement) is not supported in this version.
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