Hex-Oct DecoderConverts an octal and hexadecimal escape sequence to a string.
Combinations of characters consisting of a backslash (\) followed by a letter or a set of numbers are called escape sequences. Escape sequences must be used to represent a newline character, single quote, or some other character in a character constant. The escape sequence is treated as a single character and is therefore a valid character constant.
Surely you have seen in the code a string like $_SERVER["\x44\117\x43\125\115\x45\116\x54\x5f\x52\x4f\117\124"], but did not understand what is hidden behind this set of characters. This is a fairly common way to hide malicious code, this line is identical to $_SERVER["DOCUMENT_ROOT"]. With the Hex-Oct decoder, you can easily convert such expressions into human-readable code.