Convert numbers between binary, octal, decimal and hexadecimal instantly with this free number base converter. Enter a value in any base and see it translated into all the others — essential for programmers, students and electronics hobbyists.
How to Use
- Type the number you want to convert.
- Choose the base it is written in — binary, octal, decimal or hexadecimal.
- Click Convert to see the value in all four bases.
- Use Reset to clear the form and convert another number.
Key Features
- Four bases at once. Binary, octal, decimal and hexadecimal shown together.
- Helpful validation. Tells you clearly when digits do not fit the chosen base.
- Negative numbers. Values like -42 or -FF convert correctly.
- Private and instant. Everything runs in your browser; no data leaves your device.
- Free, no sign-up. Convert as many numbers as you like.
FAQs
What is a number base?
The base is how many distinct digits a number system uses. Decimal uses ten digits (0–9), binary uses two (0–1) and hexadecimal uses sixteen (0–9 plus A–F).
Why do programmers use hexadecimal and binary?
Computers store everything as binary. Hexadecimal is a compact way to write binary — each hex digit represents exactly four bits — which is why you see it in colour codes, memory addresses and debugging.
Does it handle fractions?
No. This converter works with whole numbers (integers) only, which covers the vast majority of base-conversion tasks.
Is any of my data stored?
No. All conversions happen locally in your browser, and the numbers you enter never leave your device.
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