Base Converter

Convert Numbers Between Binary, Octal, Decimal, Hexadecimal, and Base-36

Software developers, network engineers, and students constantly switch between number systems. A subnet mask lives in binary, a color code in hex, a file permission in octal, and everyday arithmetic in decimal. Doing these conversions by hand invites mistakes, especially when values grow past the range a pocket calculator can hold.

This base converter handles binary (base-2), octal (base-8), decimal (base-10), hexadecimal (base-16), and base-36 in both directions. It uses BigInt arithmetic internally, so it stays exact for integers far beyond the 53-bit limit of ordinary JavaScript numbers. Paste a value, pick a base, and read every other representation instantly — no plugins, no server round trip, and no signup required.

How to Convert Between Number Bases

1. Type or paste the number you want to convert into the input field.
2. Choose the base of the value you entered, such as hex for FF or binary for 1010.
3. Press the convert button or wait for the live update to render.
4. Read the results across the binary, octal, decimal, hex, and base-36 output panels.
5. Swap the input and output bases and convert again when you need the reverse direction.
6. Copy any result with the copy button instead of retyping long digit strings.

Example Conversions

A developer debugging a color value pastes 7FFF00 as hex. The tool returns the binary, octal, decimal, and base-36 equivalents in one pass.

Handling Huge Integers with BigInt

Values like 9007199254740993 exceed what floating-point numbers represent exactly. This tool parses input as BigInt and formats output as BigInt, so digits never round silently. For example, a 64-bit hash fragment such as 18446744073709551615 converts to hex FFFFFFFFFFFFFFFF with every digit intact. The same guarantee applies in the other direction: paste a long hexadecimal string and read its exact decimal value without scientific notation or truncation.

Tips for Accurate Conversions

• Check the input base — a wrong input base produces a wrong result; when unsure, test with a value you already know.
• Use base-36 for short tokens — Z through 0 to 9 and A to Z compress large IDs into compact invite codes.
• Expect letter case flexibility — hex and base-36 accept both upper- and lowercase digits, while output is uppercase.
• Verify with a round trip — convert back to the original base and confirm the value matches.
• Trust BigInt for IDs — 64-bit and larger integers convert exactly without exponent notation.

When to Use This Tool

• Debugging binary data — inspect the bit pattern behind a hex dump or network packet.
• Reading permission masks — translate octal values like 644 into file permission bits.
• Generating short codes — turn numeric IDs into base-36 slugs for URLs and coupon codes.
• Color and graphics work — move between hex color values and their RGB decimal parts.
• Teaching number systems — show students how the same quantity appears in every base.

Frequently Asked Questions