U10FFFF

U+10FFFF is the highest code point defined by the Unicode standard. It lies at the upper end of the Unicode code space, which runs from U+0000 to U+10FFFF, and is located in the final plane of Unicode, commonly referred to as plane 16.

U+10FFFF is designated as a noncharacter in the Unicode specification. Noncharacters are code points that are permanently reserved and are not assigned to any character. They may appear in internal processing or testing data but are not intended for interchange as text data.

In terms of encoding, U+10FFFF can be represented in several Unicode encodings. In UTF-32 it is simply 0x00010FFFF. In UTF-16 it requires a surrogate pair, specifically the pair 0xDBFF 0xDFFF. In UTF-8 it is encoded as four bytes: F4 8F BF BF.

Because it is a noncharacter and the maximum code point, U+10FFFF serves primarily as a boundary marker within the Unicode system. It is not assigned to any graphic symbol, letter, or other textual element, and interchange of text should avoid relying on this code point for representing characters. The practical effect for most Unicode text processing is that U+10FFFF is treated as reserved and is not used for regular character data.