Number Base Converter Online — Binary, Decimal and Hex
Convert integers online between binary, octal, decimal and hexadecimal. Process large whole numbers locally with browser BigInt.
About this tool
This online number base converter reads an integer in base 2, 8, 10 or 16 and returns all four representations. It uses JavaScript BigInt, avoiding normal floating-point precision loss for large whole numbers.
How to use
- Select the base of the input integer: binary, octal, decimal or hexadecimal.
- Enter the digits without a 0b, 0o or 0x prefix.
- Convert and copy the BIN, OCT, DEC or HEX result you need.
Features
- Converts between bases 2, 8, 10 and 16.
- Uses BigInt for exact large-integer conversion.
- Runs locally without uploading numeric values.
Common use cases
- Translate binary flags or hexadecimal identifiers.
- Check integer values used in code and protocols.
- Convert large whole numbers without floating-point rounding.
Common issues and tips
- Each base accepts only its valid digits, such as 0 and 1 for binary.
- This converter handles integers and does not support fractions or decimal points.
Privacy
Number conversion runs locally in your browser. The value you enter is not uploaded to Tools12345.
Frequently asked questions
Which number bases are supported?
The tool accepts and outputs binary, octal, decimal and hexadecimal integers.
Should I include 0x before hexadecimal input?
No. Select base 16 and enter only the hexadecimal digits.
Can it convert very large integers?
Yes. Browser BigInt provides exact whole-number conversion beyond the normal safe integer range.