A CSS analyzer that measures selector complexity and performance metrics to help optimize stylesheets.
analyze-css is a CSS analysis tool that parses stylesheets and calculates metrics related to selector complexity, redundancy, and performance. It helps developers identify inefficient CSS patterns, such as overly complex selectors, duplicated properties, and outdated vendor prefixes, to optimize stylesheet performance and maintainability.
Frontend developers, performance engineers, and teams looking to audit and improve the quality and performance of their CSS codebases.
Developers choose analyze-css for its comprehensive set of performance-focused metrics, rule-based analysis that provides specific offenders, and flexibility to use via CLI or programmatically in build processes.
CSS selectors complexity and performance analyzer
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Analyzes over 30 metrics including selector specificity, duplicated properties, and old vendor prefixes, providing a comprehensive view of CSS performance and complexity as detailed in the README.
For each issue, it lists specific 'offenders' such as exact rules with !important, enabling developers to pinpoint and fix problems efficiently based on the example JSON output.
Supports local CSS files, remote URLs via HTTP with authentication and proxy options, and stdin, making it versatile for different analysis scenarios as shown in the Usage section.
Available as a CommonJS module and CLI tool, with a Grunt task provided, facilitating seamless addition to build processes and CI/CD pipelines without complex setup.
The tool only identifies issues without offering automated corrections, requiring manual intervention to resolve each reported problem, which can be time-consuming for large codebases.
The plethora of detailed metrics, such as specificity averages and redundant selectors, can be complex to interpret and act upon without deep CSS expertise, potentially overwhelming users.
It cannot analyze dynamically generated CSS from modern frameworks like CSS-in-JS, limiting its usefulness in component-based architectures that rely on runtime style generation.