About Number Base Converter

Convert between decimal, hex, octal, and binary. Part of the DevTools Surf developer suite. Browse more tools in the Encoding collection.

Use Cases

• Converting hex memory addresses for low-level debugging
• Translating CSS hex colors to decimal RGB values
• Understanding binary flag values in bitfield configurations
• Converting Unix permission octals for chmod verification

Tips

• Convert hex color codes to decimal RGB values instantly
• Use binary output to understand bitwise operations visually
• Enter values with prefixes like 0x or 0b for automatic detection

Fun Facts

• Hexadecimal notation was popularized by IBM in the 1960s for the System/360, replacing the octal system used by earlier machines.
• The binary number system was formalized by Gottfried Wilhelm Leibniz in 1703, though he credited ancient Chinese I Ching as inspiration.
• Octal (base-8) was common in early computing because the PDP-8 and other machines used 12-bit words divisible into four 3-bit groups.

FAQ

Which bases?

Binary (2), octal (8), decimal (10), hex (16). Plus custom base (2-36). All four common ones shown simultaneously for any input.

Does it handle negative numbers?

Yes — two's-complement representation for binary/hex. The tool assumes 32-bit or 64-bit context for negative values.

What about fractions?

Decimal fractions yes (0.5 in binary = 0.1). Non-terminating fractions get rounded; exact binary representations of some decimals are impossible (0.1 is repeating in binary).

Can I convert very large numbers?

Numbers up to 2^53 are precise (JavaScript Number limit). For bigger, use BigInt-specific tools.