DevTools features by host

Look up whether a DevTools feature works where you inspect the page. The panel is the same everywhere; what changes is what its host can reach.

Hosts

Vite plugin: the panel docked in Vite DevTools or in its own tab at /__lit/, which the dev server serves even without Vite DevTools, on a page your Vite dev server serves.
Chrome extension: Lit Inspector, a Lit tab in Chrome DevTools, on any http(s) page. It has no server behind it.
Firefox extension: the same extension for Firefox, from Firefox Add-ons.

lit-devtools dev behaves like the extensions, plus Export snapshot and the MCP tools, because it runs a Node server. See the CLI reference.

Where a feature depends on the browser rather than the host, the browser is named in brackets.

	Vite plugin	Chrome extension	Firefox extension
Browsers	Any (Chrome-only features marked)	Chrome 114+	Firefox 140+
Pages	Your dev server	Any http(s) page, production builds included	Any http(s) page, production builds included
Page CSP	Same-origin scripts from Vite	Not affected	Not affected
Turning it on	`timeline: true` in the plugin options	Per site, from the Lit tab	Per host, on every port, from the toolbar popup
Frames	Top page	Top frame only	Top frame only
Needs a Node server	Yes	No	No

Feature	Vite plugin	Chrome extension	Firefox extension
Live component tree	Yes	Yes	Yes
Hover highlight and Reveal	Yes	Yes	Yes
Pick an element on the page	With `sourceOverlay`	Yes, any Lit element	Yes, any Lit element
Properties, state, attributes	Yes	Yes	Yes
Tasks, signals, controllers	Yes	Yes (controllers can be missing from minified builds)	Yes (controllers can be missing from minified builds)
Native `#private` fields	With `privateFields`	No	No
Source link and Rendered at link	With `sourceOverlay`	Both, from the page’s sourcemaps and template text	Both, from the page’s sourcemaps and template text
Reveal in the Elements panel	No	Yes	Yes
Follow the Elements selection	No	Yes	Yes
Lit tab in the Elements sidebar	No	Yes	Yes
Open in the Sources panel	No	Yes	No
Open in editor	Yes	On a Vite dev server	On a Vite dev server
Docs from Custom Elements Manifests	Yes	Linked by the page, found beside its scripts, or added in Settings	Linked by the page, found beside its scripts, or added in Settings
HMR patch line and issues banner	Yes	No	No
Request update	Yes	Yes	Yes
`$lit` and Store as global variable	Yes	Yes	Yes
Flash updates	Yes	Yes	Yes
Empty-tree diagnosis (no runtime, duplicate Lit, iframe)	Yes	Yes	Yes

Feature	Vite plugin	Chrome extension	Firefox extension
Per-component counts, update time, reasons	Yes	Yes	Yes
Error attribution	Yes	Yes	Yes
Old and new values	Yes	Yes	Yes
Source and Rendered at links	With `sourceOverlay`	No	No

Feature	Vite plugin	Chrome extension	Firefox extension
Record, stop, clear	Yes	Yes	Yes
Lifecycle, changed values, mouse, keyboard, custom events layers	Yes	Yes	Yes
Render and Lit warnings layers	Yes	Lit development builds only	Lit development builds only
List and Tracks views, filters, span detail	Yes	Yes	Yes
Custom layers from `addTimelineEvent`	Yes	No	No
Export snapshot	Yes	No	No
Performance tracks	Yes (Chrome 134+: a Lit track group; other browsers: User Timing marks)	Yes (Chrome 134+: a Lit track group; Chrome 114–133: User Timing marks)	User Timing marks, in the Firefox Profiler’s Marker Chart

Feature	Vite plugin	Chrome extension	Firefox extension
Light and dark appearance	Yes	Yes	Yes
Plugin settings and live overrides	Yes	No	No
Page preferences (flash, performance tracks)	Yes	Yes	Yes
About (versions, duplicate Lit, layers)	Yes	Yes	Yes
Hot patching and the HMR indicator	Yes	No	No
Deep links (`#tab=…&component=…`)	Yes	No	No
Follows the page you switch to	Across tabs, with a notice	The inspected tab, across navigations	The inspected tab, across navigations
MCP tools for coding agents	Yes	No	No

DevTools architectureWhere the panel runs, how it reaches the page, and where its settings live.

CompatibilitySupported Node, Vite, Lit and browser versions.