Convierte caracteres especiales en entidades HTML seguras.
Cuando insertas texto en una página HTML, caracteres como <, > y & pueden romper el markup o crear vulnerabilidades. Esta herramienta los convierte en entidades.
& becomes &, < becomes <, > becomes >, a double quote becomes " and a single quote becomes '.
The ampersand, less-than, greater-than, double quote and single quote. Those five are enough to make text safe inside element content and inside quoted attribute values.
It is the right fix for text placed in element content or in a quoted attribute. It does not cover every context. Text placed inside a script block, a URL or a style needs different handling.
' is not defined in HTML 4 and some older browsers ignore it. The numeric form works everywhere.
It writes every character outside plain ASCII as a numeric entity, for example é becomes é. Use it when the page or the channel cannot be trusted to carry UTF-8.