Number Base Converter
Convert integers between decimal, binary, octal and hexadecimal — instant, in your browser.
100% in your browser
No watermark
No sign-up
How it works
- Select the base of the number you want to convert (DEC, BIN, OCT or HEX).
- Type your number into the input field — conversion happens live as you type.
- Read the results in all four bases below, and copy any row with one click.
Frequently asked questions
- What number bases are supported?
- Decimal (base 10), Binary (base 2), Octal (base 8) and Hexadecimal (base 16). These cover the most common programming and electronics use-cases.
- Can I enter a hexadecimal number starting with 0x?
- Yes — the tool strips the 0x, 0b and 0o prefixes automatically, so you can paste numbers from code directly.
- Is there a size limit?
- The tool uses JavaScript's standard parseInt and toString, which work correctly for integers up to 2⁵³ − 1 (Number.MAX_SAFE_INTEGER). Very large numbers will show a "Too large" notice.
- Does anything leave my device?
- No. All conversion runs locally in your browser using plain JavaScript. No data is ever uploaded.