diff --git a/app/main.py b/app/main.py
index 3d17a18..74ebed9 100644
--- a/app/main.py
+++ b/app/main.py
@@ -1521,6 +1521,7 @@ async def preview(job_id: str, request: Request, user: str = Depends(check_auth)
                 "Accept-Ranges": "bytes",
                 "Content-Length": str(chunk_size),
                 "Content-Type": "video/mp4",
+                "Cache-Control": "no-cache, must-revalidate",  # browser ne sme cachat starega output-a
             }
             return StreamingResponse(iter_file(), status_code=206, headers=headers,
                                       media_type="video/mp4")
@@ -1531,7 +1532,11 @@ async def preview(job_id: str, request: Request, user: str = Depends(check_auth)
     return FileResponse(
         out,
         media_type="video/mp4",
-        headers={"Accept-Ranges": "bytes", "Content-Length": str(file_size)},
+        headers={
+            "Accept-Ranges": "bytes",
+            "Content-Length": str(file_size),
+            "Cache-Control": "no-cache, must-revalidate",  # browser ne sme cachat starega output-a
+        },
     )
 
 
diff --git a/templates/index.html b/templates/index.html
index 3bfe3f7..ec2041a 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -1773,15 +1773,17 @@
 
     function previewJob(id, title) {
       // Odpre velik modal z reel videom
+      // Dodaj timestamp cache-buster da browser ne servira starega cached output-a
+      const cacheBust = Date.now();
       const overlay = document.createElement("div");
       overlay.className = "modal-overlay";
       overlay.innerHTML = `
         <div class="modal-content" onclick="event.stopPropagation()">
           <button class="modal-close" title="Zapri (ESC)">×</button>
-          <video src="/api/preview/${id}" controls autoplay playsinline></video>
+          <video src="/api/preview/${id}?v=${cacheBust}" controls autoplay playsinline></video>
           ${title ? `<div class="modal-title">${title}</div>` : ""}
           <div class="modal-actions">
-            <button class="primary" onclick="window.open('/api/download/${id}')">⬇ Prenesi reel</button>
+            <button class="primary" onclick="window.open('/api/download/${id}?v=${cacheBust}')">⬇ Prenesi reel</button>
             <button onclick="closeModal()">Zapri</button>
           </div>
         </div>