ASCII converter

ASCII converter is a free tool that converts text characters to numeric ASCII values and converts ASCII codes back to text.

Why are letters represented by ASCII numbers?

ASCII assigns a number from 0 through 127 to each supported letter, digit, punctuation mark, and control character. It is a 7-bit character encoding, so the same value has a consistent meaning in systems that use standard ASCII.

Uppercase and lowercase letters have different values. For example, uppercase A is 65, while lowercase a is 97. Digits also have character codes, so the character 0 is 48 rather than the numeric value 0.

A compact conversion walkthrough

Enter text in To ascii to obtain its character values, or enter numeric codes in To text to perform the reverse operation. The conversion uses PHP byte functions, including ord and chr, and the result appears in Ascii.

For a small example, the text CAT consists of C, A, and T. Their decimal ASCII values are 67, 65, and 84. Converting those values back produces CAT.

The conversion runs on the server. Input travels to the server over HTTPS and is not stored, so avoid entering secrets if your security policy prohibits sending them to an online service.

When do ASCII codes matter in real systems?

ASCII codes matter when software, devices, or protocols represent commands and readable characters as bytes. Common examples include:

• Checking delimiters, line endings, and control characters in source code or imported data.
• Reading text-based commands and responses from routers, modems, and other network equipment.
• Working with serial communication between microcontrollers, sensors, and electronics test equipment.
• Completing programming exercises that require decimal character values.
• Interpreting command or status data used by some radio equipment and amateur packet-radio applications.

ASCII values can also be written in hexadecimal or binary. For example, decimal 65 is hexadecimal 41 and binary 01000001. The Hex converter or Binary converter can help when documentation uses those forms.

How can I catch ASCII conversion errors by hand?

Check whether you are converting a character or treating the input as an ordinary number. A common mistake is writing 7 for the character 7, even though its ASCII value is 55.

Other useful checks include:

1. Preserve letter case because A and a do not share a code.
2. Count spaces because a space is character 32, not an empty position.
3. Distinguish the NUL control code 0 from the printed digit 0 at code 48.
4. Confirm the number base because 41 means A in hexadecimal but a right parenthesis in decimal ASCII.

What does ASCII leave out?

ASCII does not contain accented letters, emoji, or writing systems such as Arabic, Chinese, or Cyrillic. Those characters normally use Unicode encodings such as UTF-8.

This converter relies on byte-oriented PHP functions. UTF-8 characters can occupy multiple bytes, so a non-ASCII character may correspond to several byte values rather than one ASCII code. That sequence should not be described as an extended ASCII character.

Ordinary ASCII punctuation and spaces have defined values. Empty input contains no character to convert, while a long passage produces a correspondingly long sequence of values. The tool does not identify a file's encoding or repair damaged text.

Common questions about ASCII

Is ASCII case-sensitive?

Yes. Uppercase and lowercase letters have separate code ranges, so changing case changes the corresponding values. This distinction can affect comparisons, sorting, and validation rules in software.

Can ASCII represent tabs and line breaks?

Yes. ASCII includes nonprinting control characters such as horizontal tab at 9, line feed at 10, and carriage return at 13. A program may display, escape, or ignore these codes depending on its output format.

Why does Windows sometimes use two codes for a line break?

Windows text files commonly use carriage return followed by line feed, represented by decimal 13 and 10. Unix-like systems commonly use line feed alone. Mixing these conventions can produce extra blank lines or visible control characters in some software.

Can ASCII code 0 appear inside data?

Yes. Code 0 is NUL, a control character with no visible glyph. It can terminate C-style strings and can be used as padding in formats or protocols that define it that way, but its meaning depends on the surrounding system.

Should I use decimal, hexadecimal, or binary ASCII values?

Use decimal for coursework and general reference tables, hexadecimal when working with byte dumps or protocol documentation, and binary when inspecting individual bits or electronics signals. The underlying character value remains the same regardless of notation.