diff --git a/ui/src/i18n/.i18n/raw-copy-baseline.json b/ui/src/i18n/.i18n/raw-copy-baseline.json
index b1677b3366fe..100023cccc4c 100644
--- a/ui/src/i18n/.i18n/raw-copy-baseline.json
+++ b/ui/src/i18n/.i18n/raw-copy-baseline.json
@@ -456,13 +456,6 @@
       "path": "ui/src/pages/channels/view.nostr.ts",
       "text": "NIP-05"
     },
-    {
-      "count": 2,
-      "kind": "html-text",
-      "name": "text",
-      "path": "ui/src/pages/chat/components/chat-message-bubble.ts",
-      "text": "JSON"
-    },
     {
       "count": 1,
       "kind": "html-text",
diff --git a/ui/src/i18n/locales/en.ts b/ui/src/i18n/locales/en.ts
index 62c6a91fbf2f..ba14caaf60f4 100644
--- a/ui/src/i18n/locales/en.ts
+++ b/ui/src/i18n/locales/en.ts
@@ -4846,6 +4846,10 @@ export const en: TranslationMap = {
     },
     codeBlock: {
       jsonLines: "JSON · {count} lines",
+      jsonBadge: "JSON",
+      jsonArrayItem: "Array ({count} item)",
+      jsonArrayItems: "Array ({count} items)",
+      jsonObjectKeys: "Object ({count} keys)",
     },
     workspaceConflict: {
       titleOne: "1 cloud workspace conflict",
@@ -5092,6 +5096,7 @@ export const en: TranslationMap = {
       showLess: "Show less",
       showMore: "Show more",
       unknownDate: "Unknown date",
+      toolSender: "Tool",
       voiceNote: "Voice note",
       duplicatesCollapsed: "{count} consecutive identical messages collapsed",
       contextFor: "Message context for {timestamp}",
diff --git a/ui/src/pages/chat/components/chat-message-bubble.ts b/ui/src/pages/chat/components/chat-message-bubble.ts
index fd7314dd0105..35d841cb02a5 100644
--- a/ui/src/pages/chat/components/chat-message-bubble.ts
+++ b/ui/src/pages/chat/components/chat-message-bubble.ts
@@ -511,7 +511,7 @@ export function renderGroupedMessage(
                             ?open=${Boolean(opts.autoExpandToolCalls)}
                           >
                             <summary class="chat-json-summary">
-                              <span class="chat-json-badge">JSON</span>
+                              <span class="chat-json-badge">${t("chat.codeBlock.jsonBadge")}</span>
                               <span class="chat-json-label"
                                 >${jsonSummaryLabel(jsonResult.parsed)}</span
                               >
@@ -575,7 +575,7 @@ export function renderGroupedMessage(
             ${jsonResult
               ? html`<details class="chat-json-collapse">
                   <summary class="chat-json-summary">
-                    <span class="chat-json-badge">JSON</span>
+                    <span class="chat-json-badge">${t("chat.codeBlock.jsonBadge")}</span>
                     <span class="chat-json-label">${jsonSummaryLabel(jsonResult.parsed)}</span>
                   </summary>
                   <pre class="chat-json-content"><code>${jsonResult.pretty}</code></pre>
diff --git a/ui/src/pages/chat/components/chat-message-group.ts b/ui/src/pages/chat/components/chat-message-group.ts
index 46cf15f042f1..dab3b21cd421 100644
--- a/ui/src/pages/chat/components/chat-message-group.ts
+++ b/ui/src/pages/chat/components/chat-message-group.ts
@@ -334,7 +334,7 @@ export function resolveMessageGroupSenderLabel(
     : normalizedRole === "assistant"
       ? (userLabel ?? assistantName)
       : normalizedRole === "tool"
-        ? "Tool"
+        ? t("chat.messages.toolSender")
         : group.messages.every((item) =>
               Boolean(workspaceResultConflictFromTranscript(item.message)),
             )
diff --git a/ui/src/pages/chat/components/chat-message-markdown.ts b/ui/src/pages/chat/components/chat-message-markdown.ts
index 1a80b3b53d59..d64ff782d9f9 100644
--- a/ui/src/pages/chat/components/chat-message-markdown.ts
+++ b/ui/src/pages/chat/components/chat-message-markdown.ts
@@ -52,16 +52,19 @@ export function detectJson(text: string): { parsed: unknown; pretty: string } |
 /** Build a short summary label for collapsed JSON (type + key count or array length). */
 export function jsonSummaryLabel(parsed: unknown): string {
   if (Array.isArray(parsed)) {
-    return `Array (${parsed.length} item${parsed.length === 1 ? "" : "s"})`;
+    return t(
+      parsed.length === 1 ? "chat.codeBlock.jsonArrayItem" : "chat.codeBlock.jsonArrayItems",
+      { count: String(parsed.length) },
+    );
   }
   if (parsed && typeof parsed === "object") {
     const keys = Object.keys(parsed as Record<string, unknown>);
     if (keys.length <= 4) {
       return `{ ${keys.join(", ")} }`;
     }
-    return `Object (${keys.length} keys)`;
+    return t("chat.codeBlock.jsonObjectKeys", { count: String(keys.length) });
   }
-  return "JSON";
+  return t("chat.codeBlock.jsonBadge");
 }
 
 export type MessageActionDetails = {