diff --git a/src/main/java/com/clearfolio/viewer/controller/ViewerUiController.java b/src/main/java/com/clearfolio/viewer/controller/ViewerUiController.java
index 13b5571d..9f591ccf 100644
--- a/src/main/java/com/clearfolio/viewer/controller/ViewerUiController.java
+++ b/src/main/java/com/clearfolio/viewer/controller/ViewerUiController.java
@@ -107,7 +107,7 @@ private static String viewerShellHtml(UUID docId, String initialState) {
 
                         <div class="actions" aria-label="Actions">
                           <button type="button" class="btn btn-primary" id="retry-btn">Refresh</button>
-                          <a class="btn btn-secondary" id="open-json-link" href="#" hidden>Open JSON bootstrap</a>
+                          <a class="btn btn-secondary" id="open-json-link" href="#" target="_blank" rel="noopener noreferrer" hidden>Open JSON bootstrap <span class="sr-only">(opens in a new tab)</span></a>
                         </div>
                       </section>
 
diff --git a/src/main/resources/static/assets/viewer/viewer.css b/src/main/resources/static/assets/viewer/viewer.css
index 9245c365..6aa04fe5 100644
--- a/src/main/resources/static/assets/viewer/viewer.css
+++ b/src/main/resources/static/assets/viewer/viewer.css
@@ -209,6 +209,42 @@ a:hover {
   background: #fbfcfe;
 }
 
+.btn[aria-disabled="true"] {
+  opacity: 0.6;
+  cursor: not-allowed;
+  pointer-events: none;
+}
+
+.spinner {
+  display: inline-block;
+  width: 1em;
+  height: 1em;
+  border: 2px solid currentColor;
+  border-right-color: transparent;
+  border-radius: 50%;
+  animation: spin 0.75s linear infinite;
+  margin-right: 8px;
+  vertical-align: middle;
+}
+
+@keyframes spin {
+  100% {
+    transform: rotate(360deg);
+  }
+}
+
+.sr-only {
+  position: absolute;
+  width: 1px;
+  height: 1px;
+  padding: 0;
+  margin: -1px;
+  overflow: hidden;
+  clip: rect(0, 0, 0, 0);
+  white-space: nowrap;
+  border: 0;
+}
+
 .preview {
   border-radius: 12px;
   border: 1px dashed rgba(16, 32, 50, 0.26);
diff --git a/src/main/resources/static/assets/viewer/viewer.js b/src/main/resources/static/assets/viewer/viewer.js
index 8b0dfe00..e9848169 100644
--- a/src/main/resources/static/assets/viewer/viewer.js
+++ b/src/main/resources/static/assets/viewer/viewer.js
@@ -45,6 +45,8 @@ function setLoading(message) {
   el.error.hidden = true;
   el.liveStatus.textContent = message;
   el.preview.setAttribute("aria-busy", "true");
+  el.retryBtn.setAttribute("aria-disabled", "true");
+  el.retryBtn.innerHTML = `<span class="spinner" aria-hidden="true"></span> Refresh`;
 }
 
 function showError(message) {
@@ -52,6 +54,8 @@ function showError(message) {
   el.errorMessage.textContent = message;
   el.liveStatus.textContent = "";
   el.preview.setAttribute("aria-busy", "false");
+  el.retryBtn.setAttribute("aria-disabled", "false");
+  el.retryBtn.textContent = "Refresh";
   el.errorTitle.focus();
 }
 
@@ -70,9 +74,10 @@ function clearPreview() {
 function renderPreviewLink(path) {
   const link = document.createElement("a");
   link.href = path;
-  link.textContent = "Open artifact";
+  link.innerHTML = `Open artifact <span class="sr-only">(opens in a new tab)</span>`;
   link.className = "btn btn-secondary";
-  link.rel = "noopener";
+  link.target = "_blank";
+  link.rel = "noopener noreferrer";
   el.preview.appendChild(link);
 }
 
@@ -156,6 +161,8 @@ async function poll(docId, abortSignal) {
 
     el.preview.setAttribute("aria-busy", "false");
     el.liveStatus.textContent = "Ready.";
+    el.retryBtn.setAttribute("aria-disabled", "false");
+    el.retryBtn.textContent = "Refresh";
 
     clearPreview();
     const path = bootstrap.data.previewResourcePath;
@@ -195,6 +202,9 @@ function init() {
 
   let controller = new AbortController();
   const start = () => {
+    if (el.retryBtn.getAttribute("aria-disabled") === "true") {
+      return;
+    }
     controller.abort();
     controller = new AbortController();
     void poll(docId, controller.signal);