How to use inline-critical with a build tool like Webpack?

You can integrate it as a post-processing step in your Webpack configuration by using the Node.js API to read HTML and critical CSS files, or run the CLI after the build, similar to the example usage with file reading.

inline-critical vs critters: which should I choose?

inline-critical offers more preload strategy options and explicit control over critical CSS, but critters can automatically extract critical CSS from stylesheets. Choose inline-critical if you have pre-generated critical CSS and need flexible async loading.

Can inline-critical handle CSS files with @import statements?

Yes, with the extract option and correct basePath setting, it can extract inlined styles from referenced stylesheets, which should resolve @import if the file paths are accessible during processing.

How to ignore multiple CSS files in inline-critical?

Pass an array of regex patterns to the ignore option, such as { ignore: [/bootstrap/, /vendor/] }, as shown in the example for ignoring stylesheets per regex in the README.

What's the best preload strategy for performance?

The 'default' strategy uses preload tags for good browser support, but 'media' swapping is effective for async loading without JS dependency; test based on your site's traffic and JS requirements.

Does inline-critical work with single-page applications (SPAs)?

It's designed for static HTML, so for SPAs, you'd need to pre-render pages or use it during build time for initial load optimization, but it won't handle dynamic client-side updates.

inline-critical — Critical CSS Inliner

What is inline-critical?

inline-critical is a Node.js module that optimizes CSS delivery by inlining critical-path CSS directly into HTML and asynchronously loading remaining stylesheets. It solves the render-blocking CSS problem by ensuring above-the-fold styles are available immediately while deferring non-critical styles, significantly improving perceived page load performance.

Target Audience

Frontend developers and performance engineers building websites who need to optimize CSS delivery and eliminate render-blocking resources for better Core Web Vitals scores.

Value Proposition

Developers choose inline-critical because it provides a straightforward, configurable solution for implementing critical CSS techniques without complex setup, supports multiple async loading strategies, and maintains compatibility with JavaScript-disabled browsers through automatic noscript fallbacks.

Inline critical path CSS and async load existing stylesheets

Use Cases

Best For

Implementing critical CSS techniques in static site generators
Optimizing Core Web Vitals scores by eliminating render-blocking CSS
Improving First Contentful Paint (FCP) and Largest Contentful Paint (LCP) metrics
Building performance-optimized websites with async stylesheet loading
Automating CSS optimization in CI/CD pipelines
Creating JavaScript-free fallbacks for CSS loading strategies

Not Ideal For

Projects using CSS-in-JS frameworks like Styled Components where CSS is generated dynamically at runtime
Websites with highly dynamic, user-specific content requiring real-time critical CSS extraction per request
Teams already using integrated critical CSS solutions in modern frameworks like Next.js or Gatsby
Applications needing automatic critical CSS generation without additional tooling

Pros & Cons

Pros

Flexible Async Loading

Supports multiple preload strategies like media swapping and loadCSS polyfill, allowing developers to optimize for different browser environments, as detailed in the PreloadStrategy section.

JavaScript Fallback Support

Automatically wraps original link tags in <noscript> elements, ensuring proper styling for users with JavaScript disabled, a key feature highlighted in the description.

Configurable Extraction

Enables ignoring specific stylesheets via regex patterns and extracting inlined styles from referenced files, as shown in the example usage with the ignore option.

CLI for Automation

Provides a command-line interface that works with standard input, making it easy to integrate into build pipelines and CI/CD workflows, demonstrated in the CLI section.

Cons

No Built-in Critical CSS

Requires external tools or manual effort to generate critical CSS, as it only inlines provided styles, adding an extra step to the optimization process.

Static HTML Limitation

Best suited for pre-rendered HTML files; integrating with dynamic server-side rendering frameworks may need additional configuration or workarounds.

JS-Dependent Strategies

Some preload strategies like 'swap' and 'polyfill' rely on JavaScript, which could fail if JS is blocked or slow, despite the noscript fallback.

Frequently Asked Questions

What is inline-critical?

Target Audience

Frontend developers and performance engineers building websites who need to optimize CSS delivery and eliminate render-blocking resources for better Core Web Vitals scores.

Value Proposition

Use Cases

Best For

Implementing critical CSS techniques in static site generators
Optimizing Core Web Vitals scores by eliminating render-blocking CSS
Improving First Contentful Paint (FCP) and Largest Contentful Paint (LCP) metrics
Building performance-optimized websites with async stylesheet loading
Automating CSS optimization in CI/CD pipelines
Creating JavaScript-free fallbacks for CSS loading strategies

Not Ideal For

Projects using CSS-in-JS frameworks like Styled Components where CSS is generated dynamically at runtime
Websites with highly dynamic, user-specific content requiring real-time critical CSS extraction per request
Teams already using integrated critical CSS solutions in modern frameworks like Next.js or Gatsby
Applications needing automatic critical CSS generation without additional tooling

Pros & Cons

Pros

Flexible Async Loading

Supports multiple preload strategies like media swapping and loadCSS polyfill, allowing developers to optimize for different browser environments, as detailed in the PreloadStrategy section.

JavaScript Fallback Support

Automatically wraps original link tags in <noscript> elements, ensuring proper styling for users with JavaScript disabled, a key feature highlighted in the description.

Configurable Extraction

Enables ignoring specific stylesheets via regex patterns and extracting inlined styles from referenced files, as shown in the example usage with the ignore option.

CLI for Automation

Provides a command-line interface that works with standard input, making it easy to integrate into build pipelines and CI/CD workflows, demonstrated in the CLI section.

Cons

No Built-in Critical CSS

Requires external tools or manual effort to generate critical CSS, as it only inlines provided styles, adding an extra step to the optimization process.

Static HTML Limitation

Best suited for pre-rendered HTML files; integrating with dynamic server-side rendering frameworks may need additional configuration or workarounds.

JS-Dependent Strategies

Some preload strategies like 'swap' and 'polyfill' rely on JavaScript, which could fail if JS is blocked or slow, despite the noscript fallback.

Frequently Asked Questions

inline-critical

What is inline-critical?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?

inline-critical

What is inline-critical?

Overview

Use Cases

Best For

Not Ideal For

Pros & Cons

Pros

Cons

Frequently Asked Questions

Related Projects

Found a gem we're missing?