diff --git a/ui/src/styles/components.css b/ui/src/styles/components.css
index 27dfe62d1..3b90f491b 100644
--- a/ui/src/styles/components.css
+++ b/ui/src/styles/components.css
@@ -1369,6 +1369,26 @@
   }
 }
 
+@media (max-width: 480px) {
+  .chat-compose__row {
+    flex-direction: column;
+  }
+
+  .chat-compose__actions {
+    gap: 4px;
+    justify-content: flex-end;
+  }
+
+  .chat-compose__actions .btn {
+    padding: 4px 8px;
+    font-size: 13px;
+  }
+
+  .chat-compose__actions .btn-kbd {
+    display: none;
+  }
+}
+
 /* ===========================================
    QR Code
    =========================================== */
diff --git a/ui/src/ui/app-render.ts b/ui/src/ui/app-render.ts
index d692693cb..3be692d87 100644
--- a/ui/src/ui/app-render.ts
+++ b/ui/src/ui/app-render.ts
@@ -497,6 +497,23 @@ export function renderApp(state: AppViewState) {
               onSplitRatioChange: (ratio: number) => state.handleSplitRatioChange(ratio),
               assistantName: state.assistantName,
               assistantAvatar: state.assistantAvatar,
+              // Delete session (disabled for main session)
+              isMainSession:
+                state.sessionKey === "main" ||
+                parseAgentSessionKey(state.sessionKey)?.rest === "main",
+              onDelete: async () => {
+                const { deleteSession } = await import("./controllers/sessions");
+                await deleteSession(state as Parameters<typeof deleteSession>[0], state.sessionKey);
+                // Switch to main session after deletion
+                const mainKey = state.sessionsResult?.mainSessionKey ?? "main";
+                state.sessionKey = mainKey;
+                state.applySettings({
+                  ...state.settings,
+                  sessionKey: mainKey,
+                  lastActiveSessionKey: mainKey,
+                });
+                void loadChatHistory(state);
+              },
             })
           : nothing}
 
diff --git a/ui/src/ui/views/chat.ts b/ui/src/ui/views/chat.ts
index f5fb6e80b..d92ac2ce5 100644
--- a/ui/src/ui/views/chat.ts
+++ b/ui/src/ui/views/chat.ts
@@ -68,6 +68,9 @@ export type ChatProps = {
   onCloseSidebar?: () => void;
   onSplitRatioChange?: (ratio: number) => void;
   onChatScroll?: (event: Event) => void;
+  // Delete session
+  isMainSession?: boolean;
+  onDelete?: () => void;
 };
 
 const COMPACTION_TOAST_DURATION_MS = 5000;
@@ -361,6 +364,22 @@ export function renderChat(props: ChatProps) {
             >
               ${canAbort ? "Stop" : "New session"}
             </button>
+            ${props.onDelete
+              ? html`
+                  <button
+                    class="btn"
+                    ?disabled=${!props.connected || isBusy || props.isMainSession}
+                    @click=${() => {
+                      if (confirm(`Delete session "${props.sessionKey}"?`)) {
+                        props.onDelete!();
+                      }
+                    }}
+                    title=${props.isMainSession ? "Cannot delete main session" : "Delete this session"}
+                  >
+                    🗑
+                  </button>
+                `
+              : nothing}
             <button
               class="btn primary"
               ?disabled=${!props.connected}