diff --git a/js/upload.js b/js/upload.js
index a364f49..fe1c042 100644
--- a/js/upload.js
+++ b/js/upload.js
@@ -99,9 +99,32 @@ async function beginCheck() {
     const quickMode = document.getElementById('quickMode').checked;
     if (quickMode) addLog('Quick mode enabled — skipping expensive checks', 'info');
 
+    // Animate progress while Cloud Run processes synchronously (can take 2-5 min)
+    const progressStages = [
+        { pct: 35, msg: 'Loading PDF structure...', log: 'Reading PDF metadata and tagging' },
+        { pct: 45, msg: 'Checking document structure...', log: 'Validating PDF tags and structure tree' },
+        { pct: 55, msg: 'Analyzing images with AI...', log: 'Running AI vision analysis on images' },
+        { pct: 65, msg: 'Checking color contrast...', log: 'Calculating WCAG contrast ratios' },
+        { pct: 72, msg: 'Analyzing readability...', log: 'Computing Flesch reading scores' },
+        { pct: 80, msg: 'Checking headings & links...', log: 'Heading hierarchy, tab order, role mapping' },
+        { pct: 88, msg: 'Running PDF/UA validation...', log: 'veraPDF structure validation' },
+        { pct: 94, msg: 'Compiling results...', log: 'Generating accessibility report' },
+    ];
+    let stageIdx = 0;
+    const progressTimer = setInterval(() => {
+        if (stageIdx < progressStages.length) {
+            const s = progressStages[stageIdx++];
+            updateProgress(s.pct, s.msg);
+            addLog(s.log, 'info');
+        }
+    }, 18000); // advance every 18s → covers ~2.5 min of processing
+
+    updateProgress(30, 'Analyzing PDF (this may take a few minutes)...');
+    addLog('Sent to Cloud Run for processing...', 'info');
+
     try {
-        updateProgress(30, 'Analyzing PDF (this may take a few minutes)...');
         const result = await startCheck(currentJobId, quickMode);
+        clearInterval(progressTimer);
 
         if (result.success) {
             if (result.data && result.data.status === 'completed') {
@@ -121,6 +144,7 @@ async function beginCheck() {
             document.getElementById('progressContainer').style.display = 'none';
         }
     } catch (error) {
+        clearInterval(progressTimer);
         addLog('Check error: ' + error.message, 'error');
         alert('Check failed: ' + error.message);
         document.getElementById('progressContainer').style.display = 'none';