Text to Octal Converter

What the text to octal converter does

This takes ordinary text and writes the code number of each character in octal, the base-8 system. Type your words in, press the button, and copy out the octal codes.

It is a slightly old-fashioned way to write text as numbers, and that is part of its charm, because octal character codes have a real history that still surfaces in code today.

How to use it

1. Enter your text. Type a letter, a word, or a sentence, for example Sun.
2. Press Convert. The octal codes appear in the output box.
3. Click the result to copy it. Tap the output to send it to your clipboard.

Press Reset to clear both boxes.

Each character carries a code number

Computers do not store letters as letters. Every character has a number assigned to it, its character code, and for the basic English set those numbers are fixed by the ASCII standard. Capital S is 83, lowercase u is 117, and so on. Normally you would see those codes in plain decimal, but a code is just a number, and any number can be written in another base. This tool writes each character's code in base 8.

Why the codes are spaced apart

You will see the result comes out as separate numbers with spaces between them, one code per character. That spacing matters here. An octal character code can be two or three digits long, and the lengths vary from one character to the next, so if you ran them together you would have no way to tell where one code ended and the next began. The spaces keep each character's code as its own clear unit, so the output stays readable and can be turned back into text.

A worked example with real letters

Take the word Sun, three characters.

• S has the code 83. In octal, 83 is 1 sixty-four, 2 eights, and 3 ones, which is 123.
• u has the code 117, which in octal is 165.
• n has the code 110, which in octal is 156.

So Sun becomes 123 165 156, three octal codes in a row. Each character was converted on its own, and the spaces hold them apart.

Where octal character codes show up

This is not just a curiosity. Octal was the natural counting base on many early computers, whose word sizes split neatly into three-bit groups, and that era left a lasting mark. In C and a number of languages that followed it, you can still write a character inside a string using an octal escape, a backslash followed by the octal code. So \123 in such a string means the character with octal code 123, which is the capital S. Seeing text written as octal codes makes those escape sequences far less mysterious, since they are exactly the codes this tool produces.

Questions people ask

How is text converted to octal?

Each character is replaced by its numeric code, the number ASCII assigns it, and that code is written in base 8. The codes are listed one per character, separated by spaces.

Why are there spaces between the numbers?

Because octal codes vary in length, so without spaces you could not tell where one character's code ends and the next begins. The spaces keep each code a clear, separate unit.

What is the letter S in octal?

Capital S has the code 83, which is 123 in octal. Lowercase letters have different codes, so they give different octal numbers.

What is an octal escape like \123?

It is a way some programming languages let you write a character by its octal code inside a string. \123 stands for the character whose octal code is 123, the capital S.

References

1. Cerf, V. ASCII format for Network Interchange. RFC 20, Internet Engineering Task Force. https://www.rfc-editor.org/rfc/rfc20