Aria-multilline property is used in conjunction with input type textarea. Textarea is used when user is expected to provide large content in a form. This attribute is used for fields like feedback, comments in a form.
Screen readers such as NVDA cannot identify the difference between normal text and textarea. So users who use them try filling the field in the text with limited characters. To overcome this barrier of screen readers aria-multiline property is introduced in WAI aria 1.0.
Screen reader support
Unfortunately the highly used screen reader JAWS does not support the aria-multiline attribute in any of the major browsers. NVDA supports only on internet Explorer. Interestingly NVDA supports HTML5 textarea element in all major browsers.
Below is the table showing the aria-multiline screen reader / browser support.
|Browsers/Screen Readers||FireFox 38||Internet Explorer 11||Chrome|