Number Base Converter

The Number Base Converter is a free browser-based tool that lets you instantly convert numbers between the most common numeral systems used in programming: binary (base 2), octal (base 8), decimal (base 10), and hexadecimal (base 16). It also supports any arbitrary base from 2 to 36, covering every standard positional numeral system.

Understanding number bases is fundamental to software development. Binary is the native language of digital hardware and is essential when working with bitwise operations, flags, and low-level protocols. Hexadecimal provides a compact, human-readable representation of binary data and is ubiquitous in memory addresses, color codes, and cryptographic hashes. Octal still appears in Unix file permissions and some legacy systems.

The tool converts all four common bases simultaneously as you type, eliminating the need for multiple lookups or separate conversions. Each output has a dedicated copy button so you can quickly grab the value you need. The bit visualization section displays the binary representation with 8-bit grouping, making it easy to see individual bytes and nibbles at a glance.

For numbers that exceed the range of standard JavaScript numbers, the converter uses BigInt under the hood, ensuring accurate results for arbitrarily large values. All processing runs entirely in your browser — no data is ever sent to a server, making it safe for any input.

1. Enter the number you want to convert in the Input Value field.
2. Select the input base by clicking one of the preset buttons (Binary, Octal, Decimal, Hex) or entering a custom base between 2 and 36.
3. The tool instantly displays the converted value in all four common bases: binary, octal, decimal, and hexadecimal.
4. Review the Bit Visualization section to see the binary layout with 8-bit grouping.
5. Click the copy icon next to any output to copy it to your clipboard, or press Ctrl+Shift+C to copy the decimal value.