Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal, live as you type.
Enter a number in any of four bases - binary, octal, decimal, or hexadecimal - and see it converted to the other three instantly as you type. Useful for low-level programming, debugging bitwise operations, working with color hex codes, or checking IP subnet math. Conversion happens client-side with no size limit beyond what JavaScript's number handling supports, and there's no need to remember conversion formulas or reach for a calculator.
Loading tool
How it works
- 01
Enter a number into any base field.
- 02
The other three bases update instantly.
- 03
Copy the value you need.
Details
- Category
- Developer & data
- Runs
- In your browser
- Files uploaded
- No
- Cost per run
- Free
- Sign-in
- Not required
- Works offline
- Yes, once loaded
Last updated 2026-08-03
Common questions
What characters are valid in each base?
Binary uses 0-1, octal uses 0-7, decimal uses 0-9, and hexadecimal uses 0-9 and A-F.
Does it handle negative numbers?
The converter is built for standard unsigned integer conversion across bases.
Is there a size limit on the numbers?
Very large numbers are limited by JavaScript's safe integer range; extremely long hex or binary strings may lose precision.
Does it upload my input?
No - all conversion happens locally in your browser.