Media Verdict scans your whole site — post content (all post types, drafts and revisions), post meta (featured images, WooCommerce galleries, Elementor data), term meta, user meta, options (widgets, customizer, logo, site icon) and builder/slider sources (Smart Slider 3, Revolution Slider, LayerSlider, Master Slider, Visual Composer, WPBakery, Cornerstone, Oxygen) — and tells you which media library items are in use and which have no detected usage.
Fail-safe by design:
In the Media Library (grid and list modes) used items get a green frame and unused-detected items a red frame with a badge; hovering or clicking shows the evidence (“Used in: Post #123, Product #45”).
WP-CLI: wp media-verdict scan|list|snapshot|trash|restore|report.