Add native lazy loading for images and iframes

This feature is available only in Chrome >= 76 for now.

See https://web.dev/native-lazy-loading

1 files changed, 3 insertions, 1 deletions

diff --git a/reader/sanitizer/sanitizer.go b/reader/sanitizer/sanitizer.go
index 1065e5b..642fedf 100644
--- a/reader/sanitizer/sanitizer.go
+++ b/reader/sanitizer/sanitizer.go
@@ -137,7 +137,9 @@ func getExtraAttributes(tagName string) ([]string, []string) {
 	case "video", "audio":
 		return []string{"controls"}, []string{"controls"}
 	case "iframe":
-		return []string{"sandbox"}, []string{`sandbox="allow-scripts allow-same-origin allow-popups"`}
+		return []string{"sandbox", "loading"}, []string{`sandbox="allow-scripts allow-same-origin allow-popups"`, `loading="lazy"`}
+	case "img":
+		return []string{"loading"}, []string{`loading="lazy"`}
 	default:
 		return nil, nil
 	}