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ASCII to Hex Converter

Convert ASCII text to hexadecimal instantly (e.g., 'A' = 41). Free online ASCII to hex converter for developers.

100% Client-Side Processing

Your data is converted entirely in your browser. No data is sent to any server.

Table of Contents

What is ASCII ↔ Hex conversion?

ASCII ↔ Hex conversion converts text into hexadecimal byte values (and back). Hex is a compact, developer-friendly way to inspect raw bytes.

This tool treats text as UTF-8 bytes for numeric formats (decimal/hex/binary/octal). Non-ASCII characters (like emoji) will convert to multiple bytes.

How it Works

  • Paste input (text or hex bytes).
  • Convert instantly — results update as you type.
  • Copy output with one click.

Decoding accepts spaced values (e.g. 48 65) and compact hex (e.g. 4865) when enabled.

Common Use Cases

When to use ASCII to Hex

  • Debugging network protocols and binary data
  • Working with hexadecimal color codes in programming
  • Inspecting raw byte values in files
  • URL encoding and web development

When to use Hex to ASCII

  • Decoding hexadecimal-encoded strings
  • Reading raw HTTP headers or network packets
  • Converting hex dumps back to readable text
  • Reverse engineering encoded data

Examples

Basic conversion

  • Input: Hello
  • Output: 48 65 6C 6C 6F

URL-safe encoding

  • Input: user@example.com
  • Output: 75 73 65 72 40 65 78 61 6D 70 6C 65 2E 63 6F 6D

Debugging binary protocols

  • Input: GET / HTTP/1.1
  • Output: 47 45 54 20 2F 20 48 54 54 50 2F 31 2E 31

Special characters (UTF-8 bytes)

  • Input: Hello! 👋
  • Output: 48 65 6C 6C 6F 21 20 F0 9F 91 8B

Emoji and non-ASCII characters become multi-byte sequences.

Want to look up a character code first? Check the ASCII Table for a complete reference.

Conversion Tips

Compact vs. Spaced Format

  • Spaced: 48 65 6C 6C 6F (easier to read)
  • Compact: 48656C6C6F (more compact, common in APIs)

Character Encoding

This tool treats text as UTF-8 bytes for numeric formats (decimal/hex/binary/octal). Non-ASCII characters (like emoji) will convert to multiple bytes.

Case Sensitivity

Hexadecimal values are case-insensitive. Both FF and ff represent 255.

Frequently Asked Questions

What's the difference between ASCII and Unicode?

ASCII covers 128 characters (0-127). Unicode covers many more characters. When converting to hex/binary/octal/decimal, this tool uses UTF-8 bytes, so Unicode characters may become multiple values.

Why are there spaces in my output?

Spaces make output easier to read as byte groups. You can remove spaces if you need a compact hex string for an API.

Can I convert emoji and special characters?

Yes. Non-ASCII characters are encoded using UTF-8, so emoji often become multi-byte sequences.

What's the maximum input length?

Conversion runs entirely in your browser. There is no hard limit, but very large inputs (100,000+ characters) may be slow on older devices.

Is my data being sent anywhere?

No. All conversion happens locally in your browser using JavaScript. Your input never leaves your device.

Common ASCII values

  • Space: 20 (hex) / 32 (decimal)
  • 0-9: 30-39 (hex) / 48-57 (decimal)
  • A-Z: 41-5A (hex) / 65-90 (decimal)
  • a-z: 61-7A (hex) / 97-122 (decimal)

See the full ASCII Table for all character codes. ASCII Table.