Browser support

The components use the platform first: the native element or API when the browser has it, a script fallback when it does not. The detection is done once (getSupport()), feature by feature, never by browser name.

Feature	Used by	Native when available	Fallback
<dialog> and showModal()	Modal, Dialog, Drawer	focus trap, Escape, inert page, top layer, ::backdrop	a role="dialog" with its own focus trap, Escape, backdrop and scroll lock
closedby on <dialog>	Modal, Dialog, Drawer	light dismiss without code	a click handler on the backdrop
Popover API	Tooltip, Popover, Dropdown, Combobox, DatePicker, toasts	top layer, light dismiss, Escape, focus return	hidden toggle with outside click and Escape handlers
<details name>	Accordion	exclusive group without code	the accordion closes the others itself
hidden="until-found"	Tabs panels	the page search reveals a hidden panel	the panel stays hidden until selected
<search>	DataTable filters	landmark without a role	a div with role="search"
<progress>, <meter>	Progress, Rating	built-in role and value	always available
Invoker commands	Modal, Drawer, Dropdown triggers	commandfor and command on a button	a click handler
CSS anchor positioning	floating elements	detected, see below	position computed in script (placement, flip, shift)
View Transitions	Carousel, Tabs	animated change of panel	no animation
Clipboard API	CodeBlock, Terminal copy buttons	navigator.clipboard.writeText	document.execCommand('copy') on a hidden textarea
input.showPicker()	DatePicker, TimePicker, ColorPicker	open the native picker	the custom panel
Intl	dates, numbers, plurals, lists	always used	none needed

Forcing a fallback

For tests, for an old browser you support, or to avoid a bug:

app.use(VueComponentsPlugin, { support: { popover: false, dialog: false } })

detectSupport(env) is a pure function of the environment, so every combination can be tested without a browser.