HTMLTemplateElement

<template> template

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

niso: Partial 69%. 715 of 1029 subtests pass, by system: Linux 69%, macOS 69%. Engines: QuickJS, the engine niso's WPT run uses; Node and Porffor have no recorded run. WPT results recorded at f3b4fa8, 2026-11-10; web-features 3.45.0. WPT tests · niso's support · HTMLTemplateElement

HTMLTemplateElement is an interface in idl/html.webidl, inheriting HTMLElement, 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
<template>	Widely available	Partial 69% 715 of 1029 subtests pass	2

Members

constructor

constructor

[HTMLConstructor] constructor();

content

attribute

[SameObject] readonly attribute DocumentFragment content;

int32_t niso_html_template_element_get_content(niso_dom* dom, niso_handle self, niso_handle* 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.

• htmlFor (<template for>)
• shadowRootClonable (Declarative shadow DOM)
• shadowRootCustomElementRegistry (Scoped custom element registries)
• shadowRootDelegatesFocus (Declarative shadow DOM)
• shadowRootMode (Declarative shadow DOM)
• shadowRootReferenceTarget (Reference target)
• shadowRootSerializable (Declarative shadow DOM)
• shadowRootSlotAssignment (Declarative shadow DOM)