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.
Runs on your device. This tool processes your file inside this browser tab. Nothing is uploaded, so it also works offline once the page has loaded, and closing the tab discards the file from memory.
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 2026-08-12
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.
Use this from your code
This tool is also a REST endpoint, so you can run it in a pipeline instead of by hand. It is free and needs no API key. See the API reference for every parameter.
curl -X POST https://fileoven.com/api/v1/tools/base-converter \
-H "Content-Type: application/json" \
-d '{"value":"255","from":null,"to":1}'