Online Number Base Converter — Free Binary, Octal, Decimal, Hex Converter
What is a Number Base Converter?
Computers work with binary (base-2), but humans prefer decimal (base-10). Programmers often need hexadecimal (base-16) for memory addresses and color codes, and octal (base-8) for Unix file permissions. Our Number Base Converter converts any number between all four common bases instantly.
Why Use Our Number Base Converter?
- Four bases at once — Enter a number in any base and see all four representations
- Clean display — Each base is labeled and formatted with its standard prefix (0b, 0o, 0x)
- Large number support — Works with integers up to JavaScript's safe integer limit
Ad Unit #TOOL_ABOVE
Ad Unit #TOOL_BELOW
How to Use This Number Base Converter
- Enter a number in the input field
- Select the base your input is in (BIN, OCT, DEC, or HEX)
- Click Convert
- See all four representations
Number Base Reference
| Base | Name | Digits | Prefix | Example |
|---|---|---|---|---|
| 2 | Binary | 0-1 | 0b | 0b101010 |
| 8 | Octal | 0-7 | 0o | 0o52 |
| 10 | Decimal | 0-9 | — | 42 |
| 16 | Hexadecimal | 0-9, A-F | 0x | 0x2A |
Frequently Asked Questions
When do I need a number base converter?
Common scenarios include reading memory addresses, working with bitmasks, understanding color codes (hex), interpreting Unix file permissions (octal), and debugging binary data.
What's the largest number I can convert?
The tool handles integers up to Number.MAX_SAFE_INTEGER (9,007,199,254,740,991). For even larger numbers, consider using BigInt in JavaScript.
Are my numbers saved?
No. All conversion happens locally in your browser.