Not An Element of HTML entity ∉

∉ is the HTML entity for Not An Element of ∉ (U+2209). Copy the decimal ∉ and hex ∉ codes plus CSS, JavaScript, Python and URL escapes.

Entity: ∉
Also written: &NotElement; &notinva;
Code point: U+2209
Unicode name: NOT AN ELEMENT OF
Block: Mathematical Operators
Category: Math symbol (Sm)
Since: Unicode 1.1
Defined in: HTML 4.01 and HTML5

Codes to copy

HTML named	`∉`Works in HTML; in XML only & < > " ' are predefined.
HTML decimal	`∉`Works in HTML and XML.
HTML hex	`∉`Works in HTML and XML.
CSS	`content: "\2209";`In a stylesheet, for ::before and ::after.
JavaScript	`"\u2209"`Also valid in JSON.
Python	`"\u2209"`Python 3 string literal.
Python by name	`"\N{NOT AN ELEMENT OF}"`Readable alternative using the Unicode name.
URL	`%E2%88%89`Percent-encoded UTF-8 bytes, for a path or query value.
UTF-8 bytes	`E2 88 89`3 bytes.
UTF-16	`2209`1 code unit, which is what JavaScript length counts.

When to use it

∉ writes U+2209 (Not An Element of), a maths symbol from the Unicode Mathematical Operators block, encoded since Unicode 1.1. For more than a symbol or two, MathML, supported in all major browsers since 2023, gives proper maths spacing and layout.

The name dates from HTML 4, so it works in every browser and in old email clients.

More maths operators

All maths operators · Every HTML entity · Encode or decode text

Source: the WHATWG HTML Standard list of named character references and the Unicode Character Database (Unicode 18.0).