Binary Decimal Hex Converter

Convert numbers between decimal, binary, hexadecimal and octal number systems instantly with one-click copy for each format.

Number systems explained

Computers use different number systems to represent values. Understanding how they relate helps developers work with low-level data, color codes, memory addresses, and file formats.

Decimal (Base 10)

The standard counting system using digits 0–9. This is the system humans use naturally. Example: the number 255.

Binary (Base 2)

Uses only 0 and 1. This is the fundamental language of computers — all data is stored as binary at the hardware level. Example: 255 in binary is 11111111. An 8-bit binary number represents values from 0 (00000000) to 255 (11111111).

Hexadecimal (Base 16)

Uses digits 0–9 and letters A–F. One hex digit represents exactly 4 binary bits, making hex a compact way to write binary values. Example: 255 in hex is FF. Hex is used everywhere in computing — memory addresses, color codes (#FF5733), byte values, and debugging output.

Octal (Base 8)

Uses digits 0–7. Less common today but still found in Unix file permissions (chmod 755 = binary 111 101 101) and some legacy systems.

Practical uses

• Color codes: #0284C7 → RGB components as hex → decimal values
• File permissions: chmod values in octal
• Network: IP address binary representation, subnet masks
• Low-level code: reading register values in hex from debuggers

How to use Binary Decimal Hex Converter

1. Select the number system your input is in (Decimal, Binary, Hex, or Octal).
2. Enter your number in the input field.
3. All four conversions appear instantly.
4. Click copy next to any value to copy it.

Why this tool is useful

• All four common number systems in one tool.
• Instant conversion as you type.
• Individual copy button for each base.
• Handles large numbers accurately.

Example use cases

255 decimal → Binary: 11111111 · Hex: FF · Octal: 377

FF hex → Decimal: 255 · Binary: 11111111 · Octal: 377

Frequently asked questions

Is this tool free to use?

Yes. This tool is completely free to use on Smartweb.tools, with no sign-up, subscription or hidden charges.

Which number systems are supported?

You can convert between decimal, binary, hexadecimal and octal values.

Is this useful for programming?

Yes. Developers, students and electronics hobbyists often need to convert between number systems when working with data, colours, memory and low-level code.

Does it work on mobile?

Yes. The tool is responsive and works in modern browsers on phones, tablets and desktops.

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