How recognize UTF8 file format?

You can recognize a UTF-8 file format by checking the byte order mark (BOM), which is optional but can appear as the first three bytes (0xEF, 0xBB, 0xBF). Additionally, you can look for valid UTF-8 character sequences, where each byte conforms to specific bit patterns depending on the number of bytes in the character. Tools like text editors or file command-line utilities can also identify the encoding of a file. Lastly, if a file contains a wide range of Unicode characters without showing garbled text, it's likely UTF-8 encoded.