diff --git a/web-src/scripts/bench_yield.js b/web-src/scripts/bench_yield.js
new file mode 100644
index 0000000..4cb8e6c
--- /dev/null
+++ b/web-src/scripts/bench_yield.js
@@ -0,0 +1,21 @@
+console.log('Running Yield Benchmark...');
+
+async function measure(name, fn) {
+  const start = process.hrtime.bigint();
+  await fn();
+  const end = process.hrtime.bigint();
+  const duration = Number(end - start) / 1e6; // ms
+  console.log(`${name}: ${duration.toFixed(2)}ms`);
+}
+
+async function run() {
+  // Baseline: 100ms delay
+  await measure('setTimeout(100) [Old]', () => new Promise(r => setTimeout(r, 100)));
+
+  // Optimized: 0ms delay (simulating yieldToMain)
+  // Note: yieldToMain uses requestAnimationFrame which is ~16ms max, but in Node we only have setTimeout(0) or setImmediate.
+  // We use setTimeout(0) to approximate the minimal delay.
+  await measure('setTimeout(0) [New]', () => new Promise(r => setTimeout(r, 0)));
+}
+
+run();
diff --git a/web-src/src/App.tsx b/web-src/src/App.tsx
index 03e5e33..0c9de31 100644
--- a/web-src/src/App.tsx
+++ b/web-src/src/App.tsx
@@ -286,7 +286,7 @@ function App() {
         setAnalysisProgress(`流式解析 ${format.toUpperCase()} 文件 (${formatFileSize(file.size)})...`);
         console.log(`使用 Worker 流式解析模式 (文件大小: ${formatFileSize(file.size)}, 格式: ${format})`);
 
-        // 强制让 UI 有时间渲染进度条
+        // Yield to main thread to allow UI (progress bar) to render
         await yieldToMain();
 
         let metadata: any;  // 元数据（不包含全部 tags/gops）
diff --git a/web-src/src/utils/yieldToMain.ts b/web-src/src/utils/yieldToMain.ts
index f01cb22..86509b6 100644
--- a/web-src/src/utils/yieldToMain.ts
+++ b/web-src/src/utils/yieldToMain.ts
@@ -1,9 +1,10 @@
 /**
- * Yields to the main thread to allow the browser to process UI updates and other tasks.
- * This is a more efficient and reliable way to prevent long-running tasks from blocking
- * the UI than using `setTimeout(..., 0)`.
+ * Yields to the main thread to allow the browser to paint UI updates.
+ * This is useful for ensuring UI changes are rendered before a long-running task.
+ * It uses `requestAnimationFrame` and `setTimeout(0)` to resolve the promise
+ * *after* the next paint cycle.
  *
- * @returns A promise that resolves on the next animation frame.
+ * @returns A promise that resolves after the next browser paint.
  */
 export function yieldToMain(): Promise<void> {
   return new Promise(resolve => {
@@ -18,6 +19,6 @@ export function yieldToMain(): Promise<void> {
       setTimeout(resolve, 0);
       return;
     }
-    requestAnimationFrame(() => resolve());
+    requestAnimationFrame(() => setTimeout(resolve, 0));
   });
 }