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Number Base Converter

Convert between Binary, Octal, Decimal and Hexadecimal instantly — bit visualiser, number info, fully local.

Quick:
Binary Base 2
Digits: 0, 1 — spaces ignored
Octal Base 8
Digits: 0–7
Decimal Base 10
Digits: 0–9 — max 2⁵³−1
Hexadecimal Base 16
Digits: 0–9, A–F — uppercase

Decimal value
Bits needed
Bytes
Power of 2
Bit visualiser
Enter a number to see its bits.

How it works

1
Type in any field
Enter a value in Binary, Octal, Decimal or Hexadecimal — all other fields update instantly.
2
Input validation
Each field only accepts valid characters for its base. Invalid input is highlighted in red immediately.
3
Bit visualiser
The bit grid shows every binary digit as a coloured square, grouped in bytes of 8. Bright = 1, dim = 0.
4
Number info
See the decimal value, number of bits and bytes required, and whether the number is a power of 2.