Awesome GitHub RepositoriesViewport-Based Preloading

lazysizes is a JavaScript lazy loading library and DOM visibility observer that defers the loading of images and iframes until they enter the browser viewport. It functions as a responsive image optimizer and SEO friendly asset loader designed to reduce initial page load times while maintaining search engine visibility. The project calculates optimal image sizes and handles srcset and picture elements to deliver the most appropriate asset based on device resolution and layout. It includes a mechanism for low-quality image placeholders and applies CSS classes during the loading process to trig

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

AsyncDisplayKit is an asynchronous UI framework and performance library for iOS. It provides a collection of performant alternatives to standard views, allowing developers to build responsive interfaces by offloading layout and rendering tasks to background threads. The framework is centered around a declarative layout engine based on a flexbox model, which calculates element positions and sizes asynchronously. It utilizes a node-based abstraction to wrap native views, enabling the instantiation and configuration of UI hierarchies on background threads to prevent main thread blocking. The sy

IGListKit is a data-driven list manager and framework for iOS that decouples data models from cell logic. It serves as a wrapper for collection views, using a system of section controllers to map specific data model types to independent objects that manage the logic and sizing for list sections. The project features a diffing algorithm library that calculates the minimal set of changes between two data collections. By using unique identifiers and equality tracking, it identifies inserts, deletes, and moves to trigger animated updates instead of full interface reloads. The framework covers a

Quicklink is a JavaScript library and web performance optimization tool that fetches linked resources as they enter the browser viewport. It serves as a viewport-based resource preloader and a wrapper for the browser speculation rules API to reduce perceived page load times. The library implements background page rendering and predictive resource prefetching to enable faster navigation transitions. It manages a cache of prefetched URLs and uses browser speculation rules to render full pages in the background. The tool includes capabilities for resource filtering via regular expressions, netw

instant.page is a client-side JavaScript library that preloads linked pages on hover or touch interactions, making navigation feel instantaneous without consuming unnecessary bandwidth. It works by starting to fetch a page the moment a user hovers over a link for 65 milliseconds, leaving over 300 milliseconds for the page to load before the click, and similarly preloads on touch start for mobile visitors. The script offers multiple preloading strategies to balance responsiveness with resource conservation. It can be configured to preload on mousedown, when links become visible in the viewport