Awesome GitHub RepositoriesFrontend Performance Optimization

Agent-skills is a collection of structured instructions and behavioral personas designed to standardize how AI coding agents perform engineering tasks. It functions as a workflow orchestrator that maps natural language intent to repeatable technical sequences and verification checklists. The project distinguishes itself through the use of specialized markdown-defined roles, such as security auditors or test engineers, to apply targeted domain expertise. It employs an evidence-based verification model that requires runtime data or passing tests as mandatory exit criteria to ensure AI-generated

Gatsby is a React static site generator and hybrid rendering framework used to build websites by pre-rendering components into static HTML files for delivery via content delivery networks. It functions as a hybrid rendering platform that supports a combination of static generation, server-side rendering, and deferred page loading. The framework operates as a GraphQL data aggregator, pulling content from various APIs, headless CMS integrations, and files into a single unified schema for frontend queries. It also serves as a frontend performance optimizer, automating code splitting, resource pr

This is a foundational project structure for building scalable web applications using React. It provides a standardized directory structure and build tools to accelerate the bootstrapping of new projects, featuring a Redux architecture for predictable state management through unidirectional data flow and an immutable store. The project is distinguished by a command-line interface for generating standardized components, containers, and routes from predefined templates. It implements an offline-first framework using service workers to enable progressive web app functionality, alongside a compon

Reselect is a state management optimization tool and memoization utility designed to minimize redundant calculations and UI re-renders. It functions as a library for creating memoized selectors that derive specific data from a state store. The library implements input-based memoization and recursive selector composition to create a hierarchy of derived data dependencies. It ensures reference-stable result caching and provides custom equality checking to determine when a cache should be invalidated. The project covers capabilities for derived data computation, frontend performance optimizatio

Reselect is a memoized selector framework and state selector library designed to optimize performance in Redux applications. It provides a system for computing derived data from a state store and caching the results to prevent unnecessary user interface re-renders. The library functions as a state transformation pipeline, allowing multiple selectors to be composed into chains. This enables the creation of complex data transformation pipelines where the output of one memoized selector serves as the input for another. The framework focuses on input-based memoization and referential equality ch

Ionicons is a library of hand-crafted scalable vector icons and an interface design asset pack used to build consistent user interfaces across web and mobile applications. It provides a collection of vector graphics designed for design system implementation and web component icon systems. The library includes a cross-platform icon set that automatically adapts its style based on the user's operating system to maintain a native look and feel. It also supports the integration of custom SVG assets through remote URL resolution to extend the available set of visuals. The system covers SVG asset

react-loadable is a React component lazy loader and JavaScript bundle orchestrator designed to manage the delivery of asynchronous components. It provides a bridge for server-side rendering to coordinate dynamic module preloading and prevent content flicker during client hydration. The project includes a dynamic component preloader to trigger background fetches of visual components before they are required on screen. It utilizes a system to map individual modules to their respective bundles, ensuring the correct assets are delivered. The library covers code splitting workflows and asynchrono

Reactotron is a desktop application and collection of developer tools designed for monitoring runtime errors, analyzing network requests, and inspecting state within JavaScript and React environments. It serves as a debugger for both React JS and React Native projects, providing a visual interface to monitor internal application state and performance. The tool provides specialized inspectors for React Native mobile applications and React web applications. It allows for the real-time tracking of state changes and the dispatching of actions to a state manager to test different application scena

This project is a browser API compatibility guide and replacement library designed to help migrate legacy codebases from jQuery to native browser APIs. It serves as a reference guide for finding vanilla JavaScript alternatives to common library methods. The resource focuses on vanilla JavaScript migration to reduce dependency overhead and improve page load times. It provides a mapping of library-specific functions to standard JavaScript methods to support frontend performance optimization and modern web development. The guide covers DOM manipulation, event handling, and the implementation of

SnackUI is a cross-platform UI framework and universal component library designed to share styling and components between React and React Native. It functions as a CSS-in-JS compiler that ensures visual parity across web and mobile environments. The framework utilizes a build-time tool to convert styles into atomic CSS or hoisted objects. This process optimizes runtime performance and loading speeds by extracting styles during the compilation phase. The system provides a set of adaptable interface elements and a mapping layer that renders a single component definition into platform-specific

single-spa is a microfrontend orchestration framework designed to compose multiple independent frontend applications into a single interface. It functions as a frontend routing engine and lazy-loading application loader that mounts and unmounts microfrontends based on the current URL without requiring a browser refresh. The framework enables multi-framework frontend integration, allowing different JavaScript frameworks to coexist on one page. This architecture supports distributed frontend development, where separate teams develop and deploy modules independently while maintaining a unified u

This project is a Hacker News clone built with Vue.js. It serves as a demonstration of a server-side rendered application and a progressive web app that supports offline access and mobile installation. The application showcases the implementation of centralized state management for coordinating global data flow and a routing system that features route-level code splitting and animated view transitions. It covers broader capabilities in frontend route optimization, server-side rendering for improved initial load speeds, and the use of service workers and app manifests to enable offline functi

Effeckt.css is a hardware-accelerated CSS animation library and UI transition framework. It provides a collection of styles designed to create smooth element entrances, exits, and attention-grabbing visual effects while preventing visual stuttering during interface transitions. The library focuses on high-performance animations using GPU-accelerated properties to ensure fluid movement. It enables the simulation of application navigation by sliding page views in and out of the viewport from specified directions. The framework covers a suite of visual capabilities, including directional entran

React-player is a media player component for React that provides a unified interface for embedding and playing video and audio content from various URLs and third-party platforms. It functions as a universal media player that automatically detects the source of a provided URL to render the appropriate player for that specific provider. The project distinguishes itself by wrapping diverse media SDKs and native elements into a consistent multi-platform wrapper. This allows for a standardized set of playback controls across different streaming services and includes the ability to register custom

This project is a pre-configured development boilerplate for building applications using the Angular framework and the Webpack module bundler. It provides a standardized environment that integrates a dockerized development setup to ensure consistent build and execution across different operating systems. The blueprint includes a production pipeline focused on frontend performance, utilizing ahead-of-time compilation and lazy loading to reduce bundle sizes. It also incorporates a built-in Sass styling integration to process SCSS files into CSS and an automated testing suite with integration fo

art-template is a JavaScript templating engine and HTML template compiler that transforms custom syntax and script statements into optimized HTML output. It functions as a precompiled template engine that converts template source into standalone JavaScript functions to render dynamic content from data. The engine features a template inheritance framework that organizes layouts through nesting, blocks, and inclusions to create reusable components across multiple files. It incorporates automatic output sanitization and encoding to prevent cross-site scripting attacks. The system includes capab

This repository is a collection of Webpack configuration examples and JavaScript module bundler demonstrations. It provides asset pipeline tutorials and frontend build tool examples focused on resolving dependencies and merging multiple modules into optimized browser files. The project demonstrates how to configure Webpack for transforming JavaScript assets, including the use of loaders and plugins to process JSX, CSS, and images into browser-ready formats. It includes practical examples of code splitting, minification, and environment variable injection. The covered capabilities include fro

This project is a software engineering style guide and a curated collection of architectural patterns and coding standards. It provides a multi-language coding standard to ensure maintainable software across Ruby, Python, JavaScript, and Swift. The project establishes a development workflow specification for version control, continuous integration, and peer review to maintain a linear project history. It also includes a web accessibility framework based on ARIA and WCAG standards, using design tokens and semantic HTML patterns to build inclusive interfaces. The guides cover a broad range of

Uncss is a build pipeline CSS optimizer and optimization tool designed to remove unused styles from stylesheets. It analyzes HTML files to identify and strip selectors that do not match any elements in the markup, reducing the final stylesheet size and overall web page weight. The tool functions as a DOM-based CSS analyzer that can simulate runtime document states. It provides mechanisms to preserve required selectors through the use of literal names, regular expressions, and specialized CSS comment markers to ensure styles triggered by user interactions are not deleted. The project supports

This project is a comprehensive collection of frontend development best practices and standards. It provides guides for writing semantic HTML, efficient CSS, and functional JavaScript to improve overall web performance and accessibility. The repository establishes frameworks for modern CSS architecture, focusing on specificity management and the use of Flexbox and Grid for predictable layouts. It outlines patterns for functional JavaScript programming, emphasizing the use of pure functions and composition to reduce execution time and dependency bloat. The guidelines cover several core capabi