Number Base Converter

Convert between decimal, hex, binary, and octal.

Developer

About Number Base Converter

Number bases (also called radixes) are different ways of representing the same numeric value. Decimal is what humans use daily, but computers operate in binary. Hexadecimal provides a compact way to express binary data — every hex digit maps to exactly four bits. Octal groups bits in threes and is commonly seen in Unix permission strings. This tool performs accurate base conversion and displays all four representations simultaneously, making it a time-saver for developers, students, and IT professionals.

How to Use Number Base Converter

  1. Enter the number you want to convert in the Value field.
  2. Select the Input base that matches your value (decimal, hex, binary, or octal).
  3. The tool instantly shows the equivalent value in all four bases — decimal, hexadecimal, binary, and octal.
  4. Copy any result by clicking on it or selecting the text.

Key Features

  • Simultaneous conversion to all four bases — no need to convert one at a time
  • Supports decimal, hexadecimal (0–9, A–F), binary (0–1), and octal (0–7)
  • Real-time results that update as you type
  • Clean, distraction-free interface designed for quick lookups
  • Entirely browser-based — no server calls, no data collection

When to Use This Tool

  • Debugging code that involves bitwise operations or memory addresses
  • Converting hex color codes (e.g. #FF5733) to their decimal or binary equivalents
  • Understanding or setting Unix file permissions (e.g. chmod 755)
  • Studying for computer science courses that require base conversion exercises
  • Quickly verifying manual conversions during development or homework

Technical Details

The converter uses JavaScript's built-in parseInt() to read the input in the specified base and Number.toString() to output values in each target base. Hexadecimal output is displayed in uppercase for readability. The tool handles integers within JavaScript's safe integer range. For very large numbers exceeding that range, precision may be lost. All processing takes place in the browser with zero server interaction. For related conversions, explore the Color Converter (hex ↔ RGB ↔ HSL) or the Text to Binary tool.

Conclusion

Whether you are debugging low-level code, studying number systems, or converting color values, this free Number Base Converter provides instant, accurate translations between decimal, hexadecimal, binary, and octal — all within your browser with no installation required.

Frequently Asked Questions

What number bases are supported?
Decimal (base 10), hexadecimal (base 16), binary (base 2), and octal (base 8). Enter a value and choose which base it is in; the tool shows the equivalent in all four bases.
Can I enter hex values with a 0x prefix?
The tool expects raw digits without prefixes. Remove any 0x, 0b, or 0o prefix before entering your value. Hex digits A–F are case-insensitive.
Why does conversion fail for my hex or binary input?
Hex allows only 0–9 and A–F. Binary allows only 0 and 1. Octal allows 0–7. If your input contains characters outside the valid set for the selected base, the conversion will fail. Remove spaces or invalid characters and try again.
Is my data sent to a server?
No. All conversion happens entirely in your browser using JavaScript. Nothing is uploaded or stored.