ProcessingInstruction

DOM dom

Baseline: Widely available on the web, in every major browser since Jul 2015, and long enough to count on (since Jan 2018).

niso: No WPT tests. WPT maps no test to it. WPT results recorded at f3b4fa8, 2026-11-10; web-features 3.45.0. WPT tests · niso's support · Attr, CDATASection, CharacterData, Comment

ProcessingInstruction is an interface in idl/dom.webidl, inheriting CharacterData, exposed in Window. What it does is on MDN; this page says what niso has of it.

Status

The web features its members belong to, each with its Baseline status on the web and how much of the feature’s WPT suite passes in niso (see Web platform support).

Feature	On the web	In niso	Members
DOM	Widely available	No WPT tests WPT maps no test to it	2

Members

target

attribute

readonly attribute DOMString target;

int32_t niso_processing_instruction_get_target(niso_dom* dom, niso_handle self, niso_str* out);

Not in niso yet

Members the web has, by the BCD keys web-features 3.45.0 lists, that idl/ doesn’t declare. The list is partial: web-features lists only the keys it maps to a feature.

• doc_html (HTML processing instructions)
• doc_xml (DOM)
• getAttribute (HTML processing instructions)
• getAttributeNames (HTML processing instructions)
• hasAttribute (HTML processing instructions)
• hasAttributes (HTML processing instructions)
• removeAttribute (HTML processing instructions)
• setAttribute (HTML processing instructions)
• sheet (CSS object model)
• toggleAttribute (HTML processing instructions)