This format encodes each character using uniform 4 bytes, the byte order can be elected both as Little Endian as well as Big Endian. Because of the high memory requirements, this format is rarely used. You can easily change the format of one or more files using the Text Encoder. Such a conversion from one format to another may be necessary, for example, if you would like to switch your website from ANSI to UTF-8, or if you want to read files of an unusual format and you need to change a large number of files.
Simply proceed as follows:. Learn more. What makes a file UTF-8? Ask Question. Asked 3 years, 1 month ago. Active 3 years, 1 month ago. Viewed 2k times. Opening the file in Textpad32 shows the 3 characters at the start of the file. So what makes a file UTF-8? Improve this question. Tom Blodget Gimme the Gimme the 7 7 silver badges 22 22 bronze badges.
Thats what makes a file UTF-8, really, there is nothing else to it. It is metadata. A function that reads a file with any Unicode encoding is required to strip off the optional BOM. BasilBourque Well, a BOM would help you guess but nothing internal indicates the character encoding used by a text file.
Gimme You or a program can test if a file is valid for a given character encoding. But, a program cannot say which encoding a file uses. The answer is always that it could be many. When you open a file in a text editor, it shows the author's preference from the possibilites, perhaps with heuristics. Developers needed a better way to encode all possible characters with one system. Unicode is now the universal standard for encoding all human languages.
And yes, it even includes emojis. Below are some examples of text characters and their matching code points. If you want to learn how code points are generated and what they mean in Unicode, check out this in-depth explanation. So, we now have a standardized way of representing every character used by every human language in a single library. This solves the issue of multiple labeling systems for different languages — any computer on Earth can use Unicode. Computers need a way to translate Unicode into binary so that its characters can be stored in text files.
UTF-8 is an encoding system for Unicode. It can translate any Unicode character to a matching unique binary string, and can also translate the binary string back to a Unicode character.
More specifically, UTF-8 converts a code point which represents a single character in Unicode into a set of one to four bytes. The first characters in the Unicode library — which include the characters we saw in ASCII — are represented as one byte. Characters that appear later in the Unicode library are encoded as two-byte, three-byte, and eventually four-byte binary units. Below is the same character table from above, with the UTF-8 output for each character added. Notice how some characters are represented as just one byte, while others use more.
Why would UTF-8 convert some characters to one byte, and others up to four bytes? In short, to save memory. By using less space to represent more common characters i. Spatial efficiency is a key advantage of UTF-8 encoding. If instead every Unicode character was represented by four bytes, a text file written in English would be four times the size of the same file encoded with UTF UTF-8 is the most common character encoding method used on the internet today, and is the default character set for HTML5.
Text files encoded with UTF-8 must indicate this to the software processing it. In HTML files, you might see a string of code like the following near the top:. These methods differ in the number of bytes they need to store a character. UTF-8 encodes a character into a binary string of one, two, three, or four bytes. UTF encodes a Unicode character into a string of either two or four bytes.
This distinction is evident from their names. In UTF-8, the smallest binary representation of a character is one byte, or eight bits. In UTF, the smallest binary representation of a character is two bytes, or sixteen bits.
However, they are not compatible with each other. These systems use different algorithms to map code points to binary strings, so the binary output for any given character will look different from both methods:. UTF must encode these same characters in either two or four bytes. If a website uses a language with characters farther back in the Unicode library, UTF-8 will encode all characters as four bytes, whereas UTF might encode many of the same characters as only two bytes.
Originally published Aug 10, AM, updated November 02
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