diff --git a/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/pending-and-ready.txt b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/pending-and-ready.txt
new file mode 100644
index 00000000000..6ab17b34088
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/pending-and-ready.txt
@@ -0,0 +1,4 @@
+   Animation is pending after a call to play(): true
+Animation is not pending after ready promise resolves: true
+Animation is pending after a call to pause(): true
+Animation is not pending after ready promise resolves: true
diff --git a/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/playState.txt b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/playState.txt
new file mode 100644
index 00000000000..5818651e0a2
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/playState.txt
@@ -0,0 +1,5 @@
+   Animation's playState is idle after cancel(): true
+Animation's playState is idle immediately after play(): true
+Animation's playState is paused after pause(): true
+Animation's playState is finished after finish(): true
+Animation's playState is finished after animation runs to completion: true
diff --git a/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/playbackRate.txt b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/playbackRate.txt
new file mode 100644
index 00000000000..5569ad68285
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/playbackRate.txt
@@ -0,0 +1,4 @@
+   Animation has expected currentTime value after 100ms
+Animation has expected currentTime value after 200ms
+Animation has expected currentTime value after 300ms
+Animation has expected currentTime value after 400ms
diff --git a/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/replaceState.txt b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/replaceState.txt
new file mode 100644
index 00000000000..e24cb785e57
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/replaceState.txt
@@ -0,0 +1,4 @@
+   Animation's replaceState is active initially: true
+Animation's replaceState is active after finishing: true
+Animation's replaceState is not removed after creating new animation: true
+Animation's replaceState is removed after new animation finishes: true
diff --git a/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/startTime.txt b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/startTime.txt
new file mode 100644
index 00000000000..9261dd4b16b
--- /dev/null
+++ b/Tests/LibWeb/Text/expected/WebAnimations/animation-properties/startTime.txt
@@ -0,0 +1,7 @@
+   Animation's startTime is initially null: true
+Animation's startTime is 100 after setting the value: true
+Animation's startTime is non-null after ready promise resolved: true
+Animation's startTime is null after calling cancel(): true
+Animation's startTime is null after calling pause() and setting currentTime: true
+Animation's startTime updates after reversing playbackRate: true
+Animation's startTime updates after calling finish(): true
diff --git a/Tests/LibWeb/Text/input/WebAnimations/animation-properties/pending-and-ready.html b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/pending-and-ready.html
new file mode 100644
index 00000000000..5bed417111a
--- /dev/null
+++ b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/pending-and-ready.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<div id="foo"></div>
+<script src="../../include.js"></script>
+<script>
+    asyncTest(async done => {
+        const foo = document.getElementById("foo");
+        const animation = foo.animate({}, { duration: 100 });
+
+        animation.play();
+        println(`Animation is pending after a call to play(): ${animation.pending}`);
+
+        await animation.ready;
+        println(`Animation is not pending after ready promise resolves: ${!animation.pending}`);
+
+        animation.pause();
+        println(`Animation is pending after a call to pause(): ${animation.pending}`);
+
+        await animation.ready;
+        println(`Animation is not pending after ready promise resolves: ${!animation.pending}`);
+
+        done();
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/WebAnimations/animation-properties/playState.html b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/playState.html
new file mode 100644
index 00000000000..817fa05cbec
--- /dev/null
+++ b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/playState.html
@@ -0,0 +1,25 @@
+<!DOCTYPE html>
+<div id="foo"></div>
+<script src="../../include.js"></script>
+<script>
+    test(() => {
+        const foo = document.getElementById("foo");
+        let animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+
+        animation.cancel();
+        println(`Animation's playState is idle after cancel(): ${animation.playState === "idle"}`);
+
+        animation.play();
+        println(`Animation's playState is idle immediately after play(): ${animation.playState === "running"}`);
+
+        animation.pause();
+        println(`Animation's playState is paused after pause(): ${animation.playState === "paused"}`);
+
+        animation.finish();
+        println(`Animation's playState is finished after finish(): ${animation.playState === "finished"}`);
+
+        animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        animation.currentTime = 1500;
+        println(`Animation's playState is finished after animation runs to completion: ${animation.playState === "finished"}`);
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/WebAnimations/animation-properties/playbackRate.html b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/playbackRate.html
new file mode 100644
index 00000000000..d505465be60
--- /dev/null
+++ b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/playbackRate.html
@@ -0,0 +1,35 @@
+<!DOCTYPE html>
+<div id="foo"></div>
+<script src="../../include.js"></script>
+<script>
+    asyncTest(async done => {
+        const wait = async (ms) => new Promise(resolve => setTimeout(resolve, ms));
+
+        const foo = document.getElementById("foo");
+        const animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        animation.playbackRate = 2;
+
+        // Allow 50ms of error for each test
+        await wait(100);
+        if (animation.currentTime >= 150 && animation.currentTime <= 250)
+            println("Animation has expected currentTime value after 100ms");
+
+        animation.playbackRate = 0.5;
+        await wait(100);
+        if (animation.currentTime >= 200 && animation.currentTime <= 300)
+            println("Animation has expected currentTime value after 200ms");
+
+        animation.playbackRate = -1;
+        await wait(100);
+        if (animation.currentTime >= 100 && animation.currentTime <= 200)
+            println("Animation has expected currentTime value after 300ms");
+
+        animation.playbackRate = 0;
+        const originalTime = animation.currentTime;
+        await wait(100);
+        if (animation.currentTime === originalTime)
+            println("Animation has expected currentTime value after 400ms");
+
+        done();
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/WebAnimations/animation-properties/replaceState.html b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/replaceState.html
new file mode 100644
index 00000000000..778265b0068
--- /dev/null
+++ b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/replaceState.html
@@ -0,0 +1,23 @@
+<!DOCTYPE html>
+<div id="foo"></div>
+<script src="../../include.js"></script>
+<script>
+    // Note: The "persisted" state will be tested in the Animation.persist() test
+
+    asyncTest(async done => {
+        const foo = document.getElementById("foo");
+        const animation1 = foo.animate({ opacity: [0, 1] }, { duration: 10, fill: "forwards" });
+        println(`Animation's replaceState is active initially: ${animation1.replaceState === "active"}`);
+
+        await animation1.finished;
+        println(`Animation's replaceState is active after finishing: ${animation1.replaceState === "active"}`);
+
+        const animation2 = foo.animate({ opacity: [1, 0] }, { duration: 10, fill: "forwards" });
+        println(`Animation's replaceState is not removed after creating new animation: ${animation1.replaceState === "active"}`);
+
+        await animation2.finished;
+        println(`Animation's replaceState is removed after new animation finishes: ${animation1.replaceState === "removed"}`);
+
+        done();
+    });
+</script>
diff --git a/Tests/LibWeb/Text/input/WebAnimations/animation-properties/startTime.html b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/startTime.html
new file mode 100644
index 00000000000..64e105944a5
--- /dev/null
+++ b/Tests/LibWeb/Text/input/WebAnimations/animation-properties/startTime.html
@@ -0,0 +1,34 @@
+<!DOCTYPE html>
+<div id="foo"></div>
+<script src="../../include.js"></script>
+<script>
+    asyncTest(async done => {
+        const foo = document.getElementById("foo");
+        let animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        println(`Animation's startTime is initially null: ${animation.startTime === null}`);
+        animation.startTime = 100;
+        println(`Animation's startTime is 100 after setting the value: ${animation.startTime === 100}`);
+
+        animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        await animation.ready;
+        println(`Animation's startTime is non-null after ready promise resolved: ${animation.startTime !== null}`);
+        animation.cancel();
+        println(`Animation's startTime is null after calling cancel(): ${animation.startTime === null}`);
+
+        animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        animation.pause();
+        animation.currentTime = 100;
+        println(`Animation's startTime is null after calling pause() and setting currentTime: ${animation.startTime === null}`);
+
+        animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        animation.startTime = 100;
+        animation.playbackRate = -1;
+        println(`Animation's startTime updates after reversing playbackRate: ${animation.startTime > -150 && animation.startTime < -50}`);
+
+        animation = foo.animate({ opacity: [0, 1] }, { duration: 1000 });
+        animation.finish();
+        println(`Animation's startTime updates after calling finish(): ${animation.startTime > -1050 && animation.startTime < -950}`);
+
+        done();
+    });
+</script>
