Number Base Converter
Last updated: June 1, 2026Binary, octal, decimal and hex.
Number Base Converter is a free online tool to binary, octal, decimal and hex. It runs entirely in your browser, so your files never leave your device — nothing is uploaded. There's no sign-up, no watermark, and it works on any modern browser on desktop or mobile.
How to use Number Base Converter
The Number Base Converter instantly converts a number between binary, octal, decimal and hexadecimal. It uses arbitrary-precision integers, so even very large numbers convert exactly. Free and runs entirely in your browser.
- 1Enter your value.
- 2Choose the base you're converting from.
- 3Read the binary, octal, decimal and hex results.
All four bases
See binary, octal, decimal and hexadecimal at once.
Big-number safe
Uses BigInt, so large values don't lose precision.
Free & private
Runs on your device with no sign-up.
Number Base Converter — frequently asked questions
How do I convert binary to decimal?
Select binary as the 'from' base and enter your 1s and 0s — the decimal value appears instantly, along with octal and hex.
Can it handle very large numbers?
Yes — it uses arbitrary-precision integers, so big values convert exactly without rounding.
Does it accept prefixes like 0x?
Yes, common prefixes (0x, 0b, 0o) are stripped automatically.
Is it free?
Yes, completely free.
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