Depending on the type of software, the typical solution is either configuration or charset detection heuristics. Both are prone to mis-prediction in not-so-uncommon scenarios. The encoding of text files is affected by locale setting, which depends on the user's language, brand of operating system and possibly other conditions.
Therefore, the assumed encoding is systematically wrong for files that come from a computer with a different setting, or even from a differently localized software within the same system.
For Unicode, one solution is to use a byte order mark , but for source code and other machine readable text, many parsers don't tolerate this. Another is storing the encoding as metadata in the file system. File systems that support extended file attributes can store this as user.
While a few encodings are easy to detect, in particular UTF-8, there are many that are hard to distinguish see charset detection. Mojibake also occurs when the encoding is wrongly specified. This often happens between encodings that are similar. For example, the Eudora email client for Windows was known to send emails labelled as ISO that were in reality Windows Windows contains extra printable characters in the C1 range the most frequently seen being the typographically correct quotation marks and dashes , that were not displayed properly in software complying with the ISO standard; this especially affected software running under other operating systems such as Unix.
Of the encodings still in use, many are partially compatible with each other, with ASCII as the predominant common subset. This sets the stage for human ignorance:. When there are layers of protocols, each trying to specify the encoding based on different information, the least certain information may be misleading to the recipient. The character set may be communicated to the client in any number of 3 ways:. Much older hardware is typically designed to support only one character set and the character set typically cannot be altered.
The character table contained within the display firmware will be localized to have characters for the country the device is to be sold in, and typically the table differs from country to country. As such, these systems will potentially display mojibake when loading text generated on a system from a different country. Likewise, many early operating systems do not support multiple encoding formats and thus will end up displaying mojibake if made to display non-standard text- early versions of Microsoft Windows and Palm OS for example, are localized on a per-country basis and will only support encoding standards relevant to the country the localized version will be sold in, and will display mojibake if a file containing a text in a different encoding format from the version that the OS is designed to support is opened.
UTF-8 also has the ability to be directly recognised by a simple algorithm, so that well written software should be able to avoid mixing UTF-8 up with other encodings. The difficulty of resolving an instance of mojibake varies depending on the application within which it occurs and the causes of it. Two of the most common applications in which mojibake may occur are web browsers and word processors. Modern browsers and word processors often support a wide array of character encodings.
Browsers often allow a user to change their rendering engine's encoding setting on the fly, while word processors allow the user to select the appropriate encoding when opening a file. It may take some trial and error for users to find the correct encoding. The problem gets more complicated when it occurs in an application that normally does not support a wide range of character encoding, such as in a non-Unicode computer game.
In this case, the user must change the operating system's encoding settings to match that of the game. However, changing the system-wide encoding settings can also cause Mojibake in pre-existing applications. In Windows XP or later, a user also has the option to use Microsoft AppLocale , an application that allows the changing of per-application locale settings. Even so, changing the operating system encoding settings is not possible on earlier operating systems such as Windows 98 ; to resolve this issue on earlier operating systems, a user would have to use third party font rendering applications.
Some computers did, in older eras, have vendor-specific encodings which caused mismatch also for English text. The additional characters are typically the ones that become corrupted, making texts only mildly unreadable with mojibake:. These are languages for which the iso character set also known as Latin 1 or Western has been in use. However, iso has been obsoleted by two competing standards, the backward compatible windows , and the slightly altered iso However, with the advent of UTF-8 , mojibake has become more common in certain scenarios, e.
But UTF-8 has the ability to be directly recognised by a simple algorithm, so that well written software should be able to avoid mixing UTF-8 up with other encodings, so this was most common when many had software not supporting UTF In Swedish, Norwegian, Danish and German, vowels are rarely repeated, and it is usually obvious when one character gets corrupted, e. The latter practice seems to be better tolerated in the German language sphere than in the Nordic countries. For example, in Norwegian, digraphs are associated with archaic Danish, and may be used jokingly. However, digraphs are useful in communication with other parts of the world.
Users of Central and Eastern European languages can also be affected. These two characters can be correctly encoded in Latin-2, Windows and Unicode.
Polish companies selling early DOS computers created their own mutually-incompatible ways to encode Polish characters and simply reprogrammed the EPROMs of the video cards typically CGA , EGA , or Hercules to provide hardware code pages with the needed glyphs for Polish—arbitrarily located without reference to where other computer sellers had placed them. The situation began to improve when, after pressure from academic and user groups, ISO succeeded as the "Internet standard" with limited support of the dominant vendors' software today largely replaced by Unicode.
With the numerous problems caused by the variety of encodings, even today some users tend to refer to Polish diacritical characters as krzaczki [kshach-kih], lit. Most recently, the Unicode encoding includes code points for practically all the characters of all the world's languages, including all Cyrillic characters. Before Unicode, it was necessary to match text encoding with a font using the same encoding system. Failure to do this produced unreadable gibberish whose specific appearance varied depending on the exact combination of text encoding and font encoding.
For example, attempting to view non-Unicode Cyrillic text using a font that is limited to the Latin alphabet, or using the default "Western" encoding, typically results in text that consists almost entirely of vowels with diacritical marks. Using Windows codepage to view text in KOI8 or vice versa results in garbled text that consists mostly of capital letters KOI8 and codepage share the same ASCII region, but KOI8 has uppercase letters in the region where codepage has lowercase, and vice versa.
In general, Cyrillic gibberish is symptomatic of using the wrong Cyrillic font. An estimated 1.
Therefore, these languages experienced fewer encoding incompatibility troubles than Russian. In the s, Bulgarian computers used their own MIK encoding , which is superficially similar to although incompatible with CP Although Mojibake can occur with any of these characters, the letters that are not included in Windows are much more prone to errors. All of these replacements introduce ambiguities, so reconstructing the original from such a form is usually done manually if required.
Mojibake is the garbled text that is the result of text being decoded using an unintended character encoding. The result is a systematic replacement of symbols with completely unrelated ones, often from a different writing system. This display may include the generic replacement character (" ") in places Mojibake means "character transformation" in Japanese. Mojibake (Japanese: 文字化け Pronunciation: [modʑibake] "unintelligible sequence of languages, writing from Asian languages may be replaced with other special characters, People prefer the English version of OS and other softwares.
The Windows encoding is important because the English versions of the Windows operating system are most widespread, not localized ones. The drive to differentiate Croatian from Serbian, Bosnian from Croatian and Serbian, and now even Montenegrin from the other three creates many problems. There are many different localizations, using different standards and of different quality. There are no common translations for the vast amount of computer terminology originating in English. In the end, people use adopted English words "kompjuter" for "computer", "kompajlirati" for "compile," etc.
Therefore, people who understand English, as well as those who are accustomed to English terminology who are most, because English terminology is also mostly taught in schools because of these problems regularly choose the original English versions of non-specialist software. When Cyrillic script is used for Macedonian and partially Serbian , the problem is similar to other Cyrillic-based scripts. Newer versions of English Windows allow the code page to be changed older versions require special English versions with this support , but this setting can be and often was incorrectly set.
The writing systems of certain languages of the Caucasus region, including the scripts of Georgian and Armenian , may produce mojibake.
ArmSCII is not widely used because of a lack of support in the computer industry. For example, Microsoft Windows does not support it. Another type of mojibake occurs when text is erroneously parsed in a multi-byte encoding, such as one of the encodings for East Asian languages. With this kind of mojibake more than one typically two characters are corrupted at once, e. Since two letters are combined, the mojibake also seems more random over 50 variants compared to the normal three, not counting the rarer capitals. In some rare cases, an entire text string which happens to include a pattern of particular word lengths, such as the sentence " Bush hid the facts ", may be misinterpreted.
It is a particular problem in Japan due to the numerous different encodings that exist for Japanese text. Mojibake, as well as being encountered by Japanese users, is also often encountered by non-Japanese when attempting to run software written for the Japanese market. When this occurs, it is often possible to fix the issue by switching the character encoding without loss of data. The situation is complicated because of the existence of several Chinese character encoding systems in use, the most common ones being: Unicode , Big5 , and Guobiao with several backward compatible versions , and the possibility of Chinese characters being encoded using Japanese encoding.
Cases of genuine ambiguity can sometimes be addressed by finding other characters that are not double-encoded, and expecting the encoding to be consistent:. Finally, we handle the case where the text is in a single-byte encoding that was intended as Windows all along but read as Latin The best version of the text is found using ftfy. If the file is being read as Unicode text, use that. If not, unfortunately, we have to guess what encoding it is.
It breaks down a string, showing you for each codepoint its number in hexadecimal, its glyph, its category in the Unicode standard, and its name in the Unicode standard. You may have heard of chardet. Its heuristics are designed for multi-byte encodings, such as UTF-8 and the language-specific encodings used in East Asian languages. It works badly on single-byte encodings, to the point where it will output wrong answers with high confidence. A pre-release version of ftfy 4.
There was 1 false positive, and it was due to a bug that has now been fixed. We sampled of these ftfy.
There is one string of real-world text that we have encountered that remains a false positive in the current version:. Code by Fredrik Lundh of effbot.
If you have such a ligature in your string, it is probably a result of a copy-and-paste glitch. We leave ligatures in other scripts alone to be safe.