Stylelint Config Inspector

A visual tool for inspecting and understanding your Stylelint configuration.

Screenshot

Usage

From a project that contains a Stylelint config (stylelint.config.* or .stylelintrc*), run:

npx stylelint-config-inspector@latest

Then open http://localhost:8888/ (If it does not open automatically) to explore your config.

Resolve for a target file

Use a target file so Stylelint resolves context-sensitive options (overrides, customSyntax, etc.):

npx stylelint-config-inspector --file src/styles/app.css

If you do not provide --file or --target, the inspector resolves your config against a synthetic file named stylelint-inspector-target.css relative to the resolved base path.

--file and --target are equivalent.

CLI

stylelint-config-inspector [options]
stylelint-config-inspector build [options]

Core options

• --config <configFile>: explicit config file path
• --basePath <basePath>: root path used for glob resolution
• --file <filePath>: alias of --target
• --target <filePath>: file used for effective config resolution
• --files: include matched file metadata in payload (enabled by default)
• --stats: start native Stylelint timing analysis immediately, or include its result in a static build

Performance statistics

Open Stats and select Run Analysis to profile the workspace, or start an analysis as the inspector opens:

npx stylelint-config-inspector --stats

The Slow Rules and Slow Plugins views rank native rule timings, with expandable plugin breakdowns. The summary shows elapsed run duration, reported rule time, linted files, errors, warnings, and the analysis timestamp. Analysis runs in a separate process with fixes and caching disabled; it does not apply changes to your source files or use the project's lint cache.

Profiling requires the project's Stylelint 16.13 or newer within the supported 16 and 17 major versions. It scans the same configured and common style-related file patterns as the inspector, without the Files page's display limit. Stylelint applies the project's ignores, overrides, and custom syntaxes. The displayed scope is the workspace rooted at the resolved base path: --target controls the configuration preview, not the profiling file selection, and --no-files does not disable profiling.

Timings come from Stylelint's native TIMING support. Percentages use the sum of reported rule timings, not elapsed run duration. Native rule timing does not include time spent waiting in asynchronous plugin rules; elapsed duration also includes startup, configuration loading, parsing, and other work. These results are useful for identifying expensive synchronous rules, not a complete accounting of all elapsed time. Per-file timings and separate parsing/fixing breakdowns are not available.

Reports are snapshots. Configuration updates mark a report stale; use Re-run after changing configuration or source files. A failed rerun preserves the last successful report. Only one analysis runs at a time, with a five-minute timeout.

Static build

To generate a static inspector snapshot:

npx stylelint-config-inspector build

This emits a single-page app in .stylelint-config-inspector.

Include a read-only performance report with:

npx stylelint-config-inspector build --stats

The report is saved as api/stats.json alongside the configuration payload. Static inspectors cannot start or rerun analysis; rebuild the snapshot to refresh it. A build without --stats shows instructions in the Stats tab. An explicitly requested analysis that fails also fails the build.

Both reports and navigation support a deployment prefix:

npx stylelint-config-inspector build --stats --base /tools/stylelint/

Monorepo / package subdirectory inspection

When inspecting a package inside a monorepo, set the base path for file glob matching and target resolution:

npx stylelint-config-inspector --config stylelint.config.mjs --basePath packages/web --file src/app.css

Environment aliases are also supported:

• STYLELINT_BASE_PATH (or legacy ESLINT_BASE_PATH)
• STYLELINT_TARGET (or legacy ESLINT_TARGET)

Run npx stylelint-config-inspector --help for all options.

Browser testing

See the Playwright testing guide for local and CI commands, the interaction coverage map, responsive checks, and screenshot reports.

License

Apache-2.0

Contributors ✨

Thanks goes to these wonderful people (emoji key):

9romise 💻	Nick2bad4u 🐛 💻 📖 🤔 🚇 🚧 👀 ⚠️ 🔧	Pixel998 💻 🚇	Snyk bot 🛡️ 🚇 🚧 👀	StarHeartHunt 💻	StepSecurity Bot 🛡️ 🚇 🚧	aladdin-add 💻
amareshsm 💻 🚇	antfu 💻 📖 🚇	benmccann 💻 🚇	brettz9 💻	clemyan 💻	coliff 💻	dependabot[bot] 🚇 🛡️
eslintbot 💻 📖 🚇 🚧	github-actions[bot] 🚇 🚧	hyoban 💻	kabirsky 💻 🚇	kecrily 💻 🚇	kron-sh 💻 🚇	lumirlumir 💻
lvjiaxuan 💻	mdjermanovic 💻	michkot 💻	mmkal 💻 📖	ntnyq 💻	nzakas 💻	rakleed 💻
renovate[bot] 🚇 🚧	rotu 💻	scottohara 💻	typed-sigterm 💻	vinayakkulkarni 💻	voxpelli 💻	webdiscus 💻 🚇
will-stone 💻	ycs77 💻	yidingww 💻	yuyinws 💻 🚇