Number Base Converter
Convert numbers between binary, octal, decimal and hexadecimal.
Binary for bit flags, hexadecimal for colors and memory addresses, octal for Unix permissions, decimal for humans — programming constantly hops between number bases, and mental conversion breaks down past a couple of digits.
This converter shows all four representations simultaneously: edit any one of them and the other three update live. It handles arbitrarily large integers using BigInt, so 64-bit values and beyond convert without precision loss.
How to use Number Base Converter
- 1
Type a number in any field
Binary, octal, decimal or hex — whichever you have.
- 2
Read the other bases
All representations update as you type.
- 3
Copy what you need
Each field can be copied independently.
Features
- Live four-way conversion (bases 2, 8, 10, 16)
- BigInt precision — no 53-bit float limits
- Accepts 0x/0b/0o prefixes gracefully
Frequently asked questions
Common mistakes to avoid
- Reading octal file permissions (755) as decimal.
- Converting large IDs through a float-based tool and silently losing precision past 2⁵³ — this tool uses BigInt.
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