YouTube iframe embeds often load many unnecessary resources, which slows down your page. YEP: Optimize YouTube Embeds is a lightweight WordPress plugin that replaces YouTube iframes with a clickable preview image.
The actual video loads only when the user clicks the play button, improving page load times and reducing initial page size.

External services

This plugin uses the external YouTube thumbnail service (https://i.ytimg.com) to display preview images of YouTube videos.
When a page with a YouTube embed is loaded, the plugin requests the thumbnail image directly from YouTube servers.
No personal data is sent from your site to YouTube, only the video ID (already public in the YouTube URL).