A “Kashida” is a typographic effect that justifies lines of text by elongating certain characters at carefully chosen points. It is used in Arabic writing systems. This property controls the ratio of kashida expansion to white-space expansion when justifying lines of text in an element. The property can be used with any ‘text-justify’ justification mode where kashida-style expansion is used (”auto”, “distribute”, “kashida”, and “newspaper”.)

div { text-align: justify; text-justify: newspaper; text-kashida-space: 75%; }

This is “Newspaper” justified content with text-kashida-space set to “75%”.
But it won't do anything because the content is English.

Possible Values
Value Description
inherit Text is expanded using the text expansion value set on the parent element.
[percentage] Refers to a ratio bteween kashida expansion and white-space expansion. 0% indicates white-space expansion only, while 100% indicates kashida expansion only.