How large a number can it handle?

It uses BigInt, so it handles arbitrarily large integers without losing precision.

Which bases are supported?

Binary (2), octal (8), decimal (10) and hexadecimal (16). Enter a value in any base and read the rest.

Are negative numbers supported?

Yes — a leading minus sign is preserved across all bases.

Value (base 10)

Binary11111111

Octal377

Decimal255

Hexff

Number Base Converter

The Number Base Converter converts integers between binary, octal, decimal and hexadecimal. Switching bases is constant in low-level work — reading memory addresses, bit masks, file permissions, color values and protocol fields.

Why use Number Base Converter

Binary, octal, decimal and hex side by side.
BigInt precision — no rounding on huge values.
Enter a value in any base and read all others.
Handles negative numbers.

How to use Number Base Converter

1Choose the input base. Select whether your value is binary, octal, decimal or hex.
2Type the number. Enter the value; the other bases update instantly.
3Copy. Copy the representation you need.

Frequently asked questions

How large a number can it handle?: It uses BigInt, so it handles arbitrarily large integers without losing precision.
Which bases are supported?: Binary (2), octal (8), decimal (10) and hexadecimal (16). Enter a value in any base and read the rest.
Are negative numbers supported?: Yes — a leading minus sign is preserved across all bases.

Developer notes

Hex is base-16 (0–9, a–f) and each digit maps to exactly four binary bits, which is why it's used for bytes and colors. Octal (base-8) still appears in Unix file permissions like 0755.

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Encode and decode Base64 text and files, UTF-8 safe.