Decimal converter

Decimal converter is a free tool that converts text into decimal byte values and converts decimal byte values back into text.

What does a decimal byte value mean?

A decimal byte value is a base-10 representation of a byte, usually written as a number from 0 through 255. For ordinary English letters, digits, punctuation, and control characters, these values commonly correspond to the ASCII character set.

The converter processes input byte by byte using PHP byte functions. This distinction matters for UTF-8 text. An ASCII letter occupies one byte, while an accented character, non-Latin character, or emoji may occupy several bytes and therefore produce several decimal values.

A compact decimal byte reference

Uppercase A is 65, while lowercase a is 97. The character 0 is 48, not the numeric byte value 0.

Can I convert letters to decimal and restore them?

Yes, the same ordered byte values can reconstruct the original bytes. Enter text in To decimal to obtain decimal values, or enter decimal byte values in To text for the reverse operation.

For a small example, the text Hi! consists of these decimal values:

1. H becomes 72.
2. i becomes 105.
3. ! becomes 33.

The resulting sequence is 72, 105, 33. Converting those values back in the same order produces Hi!.

This is a byte conversion, not a general number conversion. Typing the character 7 into To decimal produces the character code for the digit, which is 55. It does not return the numeric value 7.

Why might a programmer need character codes?

A programmer may need decimal character codes when inspecting raw data, following a protocol specification, or comparing bytes with documentation. Decimal notation is also useful when the surrounding material already expresses values in base 10.

• Programming: checking byte arrays, parser input, control characters, or file contents.
• Networking: examining protocol fields, packet payloads, and text sent over a socket.
• Electronics: preparing serial commands for microcontrollers, displays, or test equipment.
• Education: demonstrating how characters are stored as numeric values and practicing base conversion.
• Radio: interpreting character-based commands or data exchanged with radio equipment and packet-radio software.

Hexadecimal is often easier to align with byte boundaries because one byte fits in two hex digits. Decimal remains useful for manuals, classroom exercises, and APIs that expect ordinary base-10 integers.

What should I check before using the output?

Check the character encoding, byte sequence order, and expected value range before using the output elsewhere. The most common hand-conversion mistake is treating a character's appearance as its numeric value. For example, the digit 5 has decimal character value 53.

Spaces and punctuation are real input and have their own byte values. Empty input produces no decimal values. Very long input produces a correspondingly long decimal sequence, which can be difficult to compare manually.

Accented and non-Latin text requires extra care. UTF-8 represents many characters with multiple bytes, so the decimal output may not match a Unicode code point listed in a character chart. This converter should not be treated as a Unicode code point converter.

Frequently asked questions

Why does a null byte appear blank?

A null byte has decimal value 0 and has no visible glyph. Some software also treats it as a string terminator, so copying it into another program may shorten or alter the displayed data.

Do Windows and Unix line endings have the same decimal values?

No. A Windows text line commonly ends with carriage return followed by line feed, represented by 13 and 10. Unix-style systems commonly use line feed alone, represented by 10.

Should I use decimal, hexadecimal, or octal for byte values?

Use decimal byte notation when it is required by the specification, source code, or device manual. Hexadecimal is common for memory and packet analysis, while octal still appears in file permissions and some escape syntaxes. The Hex converter and Octal converter can help when the same byte must be written in another base.

Can control-byte output be unsafe to display?

Some control bytes can affect terminals, logs, or receiving devices instead of appearing as visible characters. Treat output from unknown data as bytes rather than commands, and inspect it in an environment that represents control values numerically.

Final checks

Keep decimal values in their original order, preserve spaces, and confirm that the receiving system expects bytes rather than Unicode code points. The conversion runs on the server. Input travels to the server over HTTPS and is not stored, so avoid submitting sensitive material if server-side processing is unsuitable for the task.