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.changeset/tiny-poems-scream.md

@@ -2,4 +2,4 @@
 'svelte': patch
 ---
 
-fix: transitions might render animated elements without animation styles applied for the duration of some rendering frames when they start
+fix: use `fill: 'forwards'` on transition animations to prevent flicker

packages/svelte/src/internal/client/dom/elements/transitions.js

@@ -382,14 +382,12 @@ function animate(element, options, counterpart, t2, on_finish) {
 	// multiplier is in effect). in the common case that it is `0`, we keep it anyway so that
 	// the CSS keyframes aren't created until the DOM is updated
 	//
-	// fill forwards to prevent the element to render without animation styles applied
+	// fill forwards to prevent the element from rendering without styles applied
-	// when entering the onfinish callback, can be verified by adding a breakpoint in the onfinish callback
 	// see https://github.com/sveltejs/svelte/issues/14732
 	var animation = element.animate(keyframes, { duration: delay, fill: 'forwards' });
 
 	animation.onfinish = () => {
-		// have to manually cancel the dummy animation to remove it from the animations stack
+		// remove dummy animation from the stack to prevent conflict with main animation
-		// because it fill forwards
 		animation.cancel();
 
 		// for bidirectional transitions, we start from the current position,