Fallbacks for HTTP 404 images in HTML and JavaScript

Fallbacks for HTTP 404 images in HTML and JavaScript provide a way to handle broken image URLs, preventing cumulative layout shift and improving the user experience. Three methods can be used: HTML <object> element with fallback image, hooking into the HTMLElement onerror event using JavaScript, and providing fallback image URLs from the server-side API. Additionally, Sentry can be used to capture and notify about image load failures, allowing for defensive coding and proactive maintenance. By implementing these fallbacks, developers can ensure a better visual end-user experience and reduce mental time spent troubleshooting broken images.