ToolVaults

Binary / Octal / Decimal / Hex Converter

Convert numbers between binary, octal, decimal, and hexadecimal. Supports huge numbers via BigInt. Handles 0b, 0o, 0x prefixes.

Runs 100% in your browser — nothing is uploaded.Use this in a chain
Input base
  • Binary11111111(base 2)
  • Octal377(base 8)
  • Decimal255
  • HexadecimalFF(base 16)

How to use

  1. 1
    Type a number in any base

    The tool auto-detects 0b (binary), 0o (octal), 0x (hex) prefixes. Or pick the input base manually.

  2. 2
    Read all four bases at once

    Binary, octal, decimal, and hexadecimal update live in one panel.

  3. 3
    Copy the value you need

    Each row has its own copy button.

Examples

Decimal 255
Input
255
Output
Binary: 11111111 · Octal: 377 · Decimal: 255 · Hex: FF
The classic byte boundary. FF hex is why "white" is #FFFFFF.
Hex color parsing
Input
0x6366F1
Output
Decimal: 6516465 · Binary: 011000110110011011110001
The 24 bits behind our accent color, straight from hex.
Big integer (128-bit)
Input
0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF
Output
Decimal: 340282366920938463463374607431768211455
BigInt-backed — no precision loss, no scientific notation.

Frequently asked

What is the max value?

Any integer that fits in JavaScript BigInt — effectively unlimited. Handles 128-bit values and beyond without loss.

Are prefixes required?

No — the tool strips 0b (binary), 0o (octal), 0x (hex) if present but doesn't require them. Just enter the digits.

Can I convert non-integers?

Not yet — floating-point base conversion is a distinct problem and gets its own tool later.

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