ASCII/Hex/Binary Converter

Convert between text (ASCII), hexadecimal, binary, and decimal representations instantly.

What Is ASCII?

ASCII (American Standard Code for Information Interchange) is a character encoding standard that maps 128 characters — including English letters, digits, punctuation, and control characters — to numeric values 0–127. Published in 1963 and standardized as RFC 20, ASCII was the foundation for virtually all modern character encodings, including UTF-8 (which is backwards-compatible with ASCII).

At the hardware level, computers store all data as binary (base-2) numbers. When you type the letter A, it's stored as the decimal value 65, which is 41 in hexadecimal and 01000001 in binary. This tool lets you convert between these representations instantly.

Number Systems at a Glance

SystemBaseDigitsExample ("A")Common Use
Decimal100–965Everyday numbers, math
Hexadecimal160–9, A–F41Memory addresses, colors (#FF0000), MAC addresses
Binary20–101000001Low-level programming, networking, bit flags
Octal80–7101Unix file permissions (chmod 755)

How to Use This Tool

  1. Select the source format (Text, Hex, Binary, or Decimal) from the "From" dropdown.
  2. Select the target format from the "To" dropdown.
  3. Enter your data in the input area.
  4. Click Convert to see the result. Use Swap Formats to reverse the conversion direction.

Common Use Cases

  • Debugging: Inspect raw byte data in hex or binary when debugging network packets, file formats, or memory dumps.
  • Web Development: Convert color codes between decimal RGB values and hexadecimal notation.
  • Cryptography: View hash outputs and encryption keys as hex strings or binary bit patterns.
  • Embedded Systems: Work with binary representations for bit manipulation, register values, and protocol headers.
  • Education: Learn how number systems work by seeing the same value in multiple bases.

Frequently Asked Questions

ASCII defines only 128 characters (English letters, digits, basic punctuation). Unicode extends this to over 154,000 characters covering every writing system. The first 128 Unicode code points are identical to ASCII, so ASCII text is automatically valid UTF-8. For Unicode conversions, try our Unicode Converter.

Each hex digit represents exactly 4 binary bits, so one byte (8 bits) is always exactly 2 hex digits. This makes hex much more compact and readable than binary — FF is easier to read than 11111111. That's why memory addresses, color codes, MAC addresses, and hash values are almost always displayed in hexadecimal.

Split the hex string into pairs of two digits. Convert each pair to a decimal number (e.g., 48 → 72, 65 → 101). Look up the decimal value in an ASCII table to find the corresponding character (72 = H, 101 = e). This tool automates the entire process for you.