Input

Enter a number to convert.

Converted

Bases

  • Binary
  • Octal
  • Decimal
  • Hexadecimal

Convert between binary, octal, decimal, and hex

Enter a number in any base and see it in binary, octal, decimal, and hexadecimal at once. It uses arbitrary-precision integers, so very large values convert exactly — and it all runs in your browser.

Features

  • Auto-detects 0x (hex), 0b (binary), and 0o (octal) prefixes.
  • Handles negative numbers and digit grouping with underscores (e.g. 1_000_000).
  • Arbitrary precision via BigInt — no rounding on large values.

Useful workflows

  • Read bitmask and permission values (e.g. 0o755, 0xFF).
  • Convert color channel or byte values while using the color converter.
  • Inspect hashes and encoded values alongside the hash & encode generator.

Frequently asked questions

How large a number can it handle?

Any size — conversion uses BigInt, so there is no 53-bit floating-point limit and no rounding.

Is my input uploaded?

No. Everything is computed locally in your browser.

Can I force a base?

Yes. Leave it on Auto-detect, or pick Binary/Octal/Decimal/Hex to interpret the input explicitly.