Number Base Converter

Convert numbers between binary, octal, decimal, and hexadecimal. All in your browser.

Binary (base 2)

Octal (base 8)

Decimal (base 10)

Hexadecimal (base 16)

Example

Type 255 in Decimal to see 11111111 (bin), 377 (oct), and FF (hex).

Only non-negative integers are supported (including large values via BigInt).

No. Enter digits only (0–9, A–F). A leading 0x is stripped if present.

Encode text to Base64 or decode Base64 to text. URL-safe mode and copy output.

Encode or decode URL components and query strings. Handles special characters.

Encode or decode HTML entities. Auto-detect and copy result.