Features of the Vitest plugin

Each row names one capability, says what it does, and links to the page that teaches it.

Taking snapshots

Feature	What it does	Guide
Automatic snapshots	Takes a snapshot at the end of every test that rendered content.	Automatic snapshots
Manual snapshots	Takes a snapshot of an element, a locator or a base64 image where you call the matcher.	Manual snapshots
Page and full-page snapshots	Captures the viewport, or the whole scrollable page.	Full-page and viewport snapshots
Snapshot subject	Snapshots a chosen element instead of document.body.	Automatic snapshots
Snapshot existence check	page.hasImageSnapshot() tells whether a snapshot exists.	Manual snapshots

Variations

Feature	What it does	Guide
Themes	One snapshot per theme for each test.	Themes
Viewports and browsers	One set of snapshots per Vitest browser instance.	Viewports and multiple instances
Workspaces	Separate options and snapshot folders for each Vitest project.	Workspaces and multiple configs

Comparing and reviewing

Feature	What it does	Guide
Pixel and SSIM comparison	Chooses how two images are compared.	Thresholds and comparison
Failure thresholds	Allows a number or a percentage of pixels to differ.	Thresholds and comparison
Per-test overrides	Changes the options for one file, one test or one call.	Thresholds and comparison
Diff image, regions file and review image	Written next to the diff when a snapshot fails.	Reviewing failures
Agent review	A skill that tells a coding agent to read the review image first.	Reviewing failures with agents
Creating baselines	Writes a missing baseline with vitest -u or createMissingBaseline.	Manual snapshots

Running everywhere

Feature	What it does	Guide
Per-platform baselines	Keeps a baseline folder for each operating system on CI.	CI
Snapshot paths	Changes the root folder, the sub-path and the key.	Configuration reference
Long path shortening	Keeps paths within Windows limits.	shortenLongSnapshotPaths
Playwright and WebdriverIO	Works with either Vitest browser provider.	Configuration
llms.txt	Lists the pages and the public API for coding agents.	llms.txt

For tool builders

Feature	What it does	Reference
Client API	The browser-side building blocks that storybook-addon-vis uses.	client-api
Server utilities	Folder constants and path helpers for Node.js code.	server-utils
Testing helpers	A sample image and a stub for testing your own integration.	testing