Decimal converter

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

How does decimal text conversion work?

Decimal text conversion represents each byte of a text string as a base-10 number. For standard ASCII characters, each letter, digit, space or punctuation mark has a value from 0 to 127. Other byte values can range up to 255.

A small worked example is the text Hi. The capital H has the decimal value 72, while the lower-case i has the value 105.

This tool uses byte-based PHP functions rather than interpreting Unicode code points. That distinction matters for accented letters, emoji and scripts such as Arabic or Japanese, which are commonly encoded as several UTF-8 bytes.

How do I use the Decimal converter?

Enter characters in To decimal to obtain their decimal byte values, or enter decimal data in To text to convert byte values back into characters. The returned result appears in the Decimal field as decimal byte values for To decimal or reconstructed text for To text.

1. Use the field that matches your source data.
2. Enter the text or decimal values without changing their order.
3. Copy the result and check that the decimal byte order, spaces and non-printing characters are preserved before using it elsewhere.

Numbers entered as text are treated as digit characters. For example, the character 7 has the ASCII decimal value 55. It is different from supplying the decimal byte value 7, which represents a non-printing control character.

Reading the result

Each decimal value corresponds to one byte, and character case affects the value. A capital A is 65, while a lower-case a is 97. Spaces and punctuation also have their own values and must be retained if the original text is to be reconstructed exactly.

An empty string contains no bytes, so there are no character values to convert. Long text produces a correspondingly long sequence because every byte needs its own number. This tool does not translate words into ordinary written numbers or convert a decimal fraction into another number base.

Where are decimal character values used?

Decimal character values are used whenever people need to inspect or document bytes in a familiar base-10 form. Hexadecimal is more compact, but decimal can be easier when checking a value against an ASCII reference table.

• Programming when checking character input, byte arrays or file contents.
• Networking when reading protocol documentation that lists field or character values in decimal.
• Electronics when sending character bytes to displays, microcontrollers or serial devices.
• Education when learning how ASCII, bytes and positional number systems relate.
• Radio when equipment documentation or data protocols specify control bytes and character codes numerically.

If a specification uses hexadecimal or octal, use a Hex converter or Octal converter rather than manually changing the notation first. An ASCII converter is useful when the task is specifically to inspect the standard ASCII character set.

What mistakes happen when converting text by hand?

One mistake is treating an entire number as one character value when it is actually several digit characters. The text 65 contains the characters 6 and 5, whose decimal ASCII values are 54 and 53. The byte value 65, by contrast, represents capital A.

Other errors include dropping the value 32 for a space, mixing upper-case and lower-case letters, or reading a hexadecimal value as decimal. Accented and non-Latin characters need extra care because a visible character may occupy more than one UTF-8 byte. A byte-by-byte result should not automatically be read as a list of Unicode code points.

Frequently asked questions

Is decimal the same as ASCII?

No. Decimal is a way of writing numbers using base 10, while ASCII is a character-encoding standard. ASCII character codes can be written in decimal, hexadecimal, octal or binary without changing the underlying character.

Can I convert emoji into one decimal number?

Usually not with a byte-based converter. An emoji commonly occupies several UTF-8 bytes, so it produces several decimal byte values rather than one Unicode code point. Use a Unicode code-point tool if you need notation such as U+1F600.

What happens to tabs and line breaks?

Tabs and line breaks are control characters with numeric byte values. A horizontal tab is byte 9, while line endings may use LF (10), CR (13) or CRLF (13 followed by 10), depending on the source system. Copying text between Windows, Linux and web applications can therefore change the byte sequence.

Can a decimal byte value be higher than 255?

A single byte cannot hold a value above 255. This converter uses byte-oriented character functions, so values from 0 to 255 are the relevant range. Larger Unicode code points require a Unicode-aware encoding step rather than direct single-byte conversion.

Does my input stay in my browser?

No. The conversion is performed on the server, so the input travels to the server over HTTPS. It is not stored.