Escape special characters to HTML entities and back: < ↔ <. Useful for showing code or markup as plain text.

The HTML Encoder / Decoder escapes special characters into HTML entities (for example < becomes <) and decodes them back. It is useful for displaying code or markup as plain text and for preventing HTML injection.
An HTML entity is a code like < or & that represents a reserved character (such as < or &) so it displays as text instead of being interpreted as markup.
Encoding reserved characters lets you show code or user input safely on a page without it being parsed as HTML, which also helps prevent cross-site scripting.