Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal instantly.
What Is a Number Base Converter?
A number base converter translates numerical values from one numeral system to another.
The most common bases in computing are binary (base 2), used internally by processors;
octal (base 8), a compact way to represent binary groups;
decimal (base 10), the standard human-readable system; and
hexadecimal (base 16), widely used in memory addresses, color codes, and low-level programming.
This tool handles arbitrarily large integers using JavaScript's native BigInt, so there is no overflow for very large numbers.
How to Use This Tool
Simply type your number in the input field, then select its source base from the dropdown — Decimal, Binary, Octal, or Hexadecimal. The converter will instantly display the equivalent value in all four bases simultaneously. You can copy any individual result with the Copy button next to it. For hexadecimal output, the tool also shows the value grouped in 2-digit byte pairs for easy reading. The info bar below the input shows the bit length, byte count, and the most significant (sign) bit of the binary representation.
Common Use Cases
Number base conversion is essential in many fields: software development (reading memory dumps, bitwise operations), web design (converting hex color codes), networking (understanding IP and MAC addresses), digital electronics (logic gate design, register values), and education (learning computer science fundamentals). Whether you are debugging a C program, inspecting raw bytes in a packet capture, or studying for a CS exam, this tool gives you instant, accurate conversions.
Frequently Asked Questions
What is the largest number this converter supports?
This tool uses JavaScript's BigInt type, which supports integers of arbitrary size — far beyond the standard 64-bit limit. You can convert extremely large numbers without any loss of precision.
Can I enter hexadecimal letters in lowercase?
Yes. The converter accepts both uppercase (A–F) and lowercase (a–f) hexadecimal digits. The output is always displayed in uppercase for consistency and readability.
Does this tool support negative numbers?
Currently this tool handles non-negative integers. Negative number representations (two's complement, sign-magnitude) vary by word size and architecture, so they are outside the scope of a simple base converter. For negative values, convert the absolute value and apply your required representation manually.
Why is hexadecimal so common in programming?
Hexadecimal is a compact representation of binary data. Each hex digit maps exactly to 4 binary bits (a nibble), so a byte is always two hex digits. This makes memory addresses, color values, and raw byte sequences much easier to read and write than their binary equivalents.
What does the "bit count" info mean?
The bit count shows how many binary digits are required to represent the number (i.e., the length of its binary form without leading zeros). For example, decimal 255 requires 8 bits. The byte count is that value divided by 8, rounded up.
Is the conversion done client-side?
Yes, entirely. All conversions happen in your browser using vanilla JavaScript — no data is sent to any server. Your input remains completely private.