Some of our customers asked why, after converting ASCII files to UTF-8 without BOM, UTFCast Pro produced output files identical to the source files. It may seem that the files were not converted. Please note that this is not a bug. The files were correctly converted; however, they happen to have the same content after conversion. This is normal behavior defined by the UTF-8 standard.

UTFCast Pro detects more than 30 code pages, one of which is ASCII. The ASCII code page means every character in the text file is a pure ASCII character (or a US-ASCII character) whose ASCII code is between 0 and 127. There are 128 pure ASCII characters in the UTF-8 character set.

A pure ASCII character remains unchanged after UTF-8 conversion for backward compatibility. If all of the characters in the input file are pure ASCII characters, then after being converted to UTF-8 without BOM, the output file will contain the same character sequence as the input file, and the file content will remain the same. The UTF-8 standard defines this behavior. Click here to read more details about UTF-8 on Wikipedia. If a file contains only pure ASCII characters, UTFCast Pro will mark it as UTF-8/US-ASCII.

In general, there is no need to convert a pure ASCII file to UTF-8 without BOM unless you need to normalize or change the line-ending type of the file. However, if you are unsure whether a file is purely ASCII or do not want to manually separate the pure ASCII files from your folder, you can rely on UTFCast Pro to handle the conversion correctly. UTFCast Pro performs every conversion strictly according to Unicode standards.