Number Base Converter

A Number Base Converter is a free tool that translates a whole number from one numeral system to another—binary (base 2), octal (base 8), decimal (base 10), hexadecimal (base 16), or any base from 2 to 36. Type a value into any field and every other base updates instantly, so you can see the same number expressed four different ways at once.

This converter runs entirely in your browser using JavaScript BigInt, which means there is no upper limit imposed by 32- or 64-bit math. You can convert astronomically large integers without losing a single digit, and nothing you type is ever sent to a server.

What is a number base?

A number base (or radix) is how many unique digit symbols a numeral system uses before it rolls over to the next place value. Decimal uses ten symbols (0–9), binary uses two (0 and 1), and hexadecimal uses sixteen (0–9 then A–F). The same quantity looks different in each system: the decimal number 42 is 101010 in binary, 52 in octal, and 2A in hexadecimal.

How to use the number base converter

1. Stay on the Standard Bases tab to work with binary, octal, decimal, and hexadecimal together.
2. Type or paste a value into whichever field you already have—for example, enter a hex color offset or a decimal count.
3. Watch the other three fields update live as you type, and check the grouped binary bit view below for a nibble-by-nibble breakdown.
4. Switch to the Arbitrary Base tab when you need a non-standard radix, pick a from base and a to base (2–36), then enter your value.
5. Use the copy buttons to grab any result, or the swap button to reverse the arbitrary-base direction.

Number base converter features

• Live four-way conversion between binary, octal, decimal, and hexadecimal—edit any field, the rest follow.
• Arbitrary base mode for any radix from 2 to 36, using digits 0–9 and letters A–Z.
• BigInt precision so huge integers convert exactly, with no floating-point rounding.
• Per-base digit validation that flags an invalid character (like a 2 in a binary field) instead of guessing.
• Grouped binary bit view that pads to whole nibbles and shows the bit and nibble count.
• 100% client-side—fast, private, and works offline once the page has loaded.

Why convert between number bases?

Programmers, students, and hardware engineers switch bases constantly. Memory addresses, bitmasks, permission flags, and color values are far easier to read in hexadecimal than in long decimal strings, while binary makes the individual on/off bits explicit. If you work with colors specifically, you might pair this with a Hex to RGB Converter to turn those hexadecimal channel values into RGB. When you need a compact, unique identifier instead of a raw number, a UUID / GUID Generator produces hexadecimal-based UUIDs that follow the same base-16 alphabet.

How is this different from text-to-binary encoding?

It is important not to confuse numeric base conversion with character encoding. This tool treats your input as a single number and re-expresses that quantity in another base. A Text to Binary Converter, by contrast, encodes each character of a string into its binary byte using a scheme like ASCII or UTF-8—so "A" becomes 01000001 because that is its code point, not because "A" is a number. Use base conversion for arithmetic values and bit patterns; use text-to-binary when you are encoding readable text. In the same spirit, a Unix Timestamp Converter interprets a decimal number as a point in time rather than simply restating it in another base.

Frequently Asked Questions

What bases can this converter handle?

The Standard Bases tab covers binary (2), octal (8), decimal (10), and hexadecimal (16) simultaneously. The Arbitrary Base tab supports any base from 2 to 36, using the digits 0–9 followed by the letters A–Z as needed.

Can it convert very large numbers?

Yes. The tool uses JavaScript BigInt, so it converts arbitrarily large integers exactly without the overflow or rounding you get from standard 64-bit numbers.

How does it validate my input?

Each field only accepts digits that are legal for its base. If you type a character that is out of range—such as an 8 in an octal field or a G in a hex field—the tool shows an inline error and pauses until you fix it.

What is the binary bit view for?

It displays the binary form grouped into 4-bit nibbles and reports the total bit count, which makes it easy to read bitmasks, spot set bits, and line values up with byte boundaries.

Is my data sent anywhere?

No. Every conversion happens locally in your browser with JavaScript. Nothing is uploaded, logged, or stored, and the tool keeps working even if you go offline after the page loads.

Does it handle negative numbers or fractions?

It converts signed whole integers, so a leading minus sign is respected. It does not convert fractional or floating-point values—enter integer quantities for accurate results.