Number Base Converter

Convert a number from one base to another — binary, octal, decimal, hexadecimal, or any base from 2 to 36. Type a number in any base and see it in all other bases simultaneously. Useful for low-level programming, debugging memory addresses, or working with different numeral systems.

What it does

▸Converts between binary (base 2), octal (base 8), decimal (base 10), and hex (base 16)
▸Supports any base from 2 to 36 (using 0-9 and A-Z as digits)
▸Shows the number in all common bases simultaneously
▸Handles large numbers correctly (BigInt support)
▸Accepts input with or without base prefixes (0x, 0b, 0o)

Use cases

▸Converting hex memory addresses to decimal for debugging
▸Converting binary flags to decimal for API parameters
▸Working with octal file permissions
▸Converting between bases for a CS assignment or interview prep

How it works

Type or paste your number into the input pane

Select the input base (or let the tool detect it from the prefix)

The number is shown in binary, octal, decimal, and hex simultaneously

Copy the base you need from the output

Frequently asked questions

1What bases are supported?

Any base from 2 to 36. Base 36 uses digits 0-9 and letters A-Z. Common bases (2, 8, 10, 16) are shown by default, and you can specify any other base in the supported range.

2Does it handle prefix notation (0x, 0b)?

Yes. The tool recognizes 0x for hex, 0b for binary, and 0o for octal prefixes. If you include a prefix, the input base is detected automatically. You can also specify the base manually.

3Can it convert very large numbers?

Yes. The converter uses BigInt internally, so numbers of arbitrary size are handled correctly. This matters for 64-bit addresses, hash values, or other large numbers that exceed JavaScript's safe integer range.