diff --git a/src/features/composer/components/Composer.tsx b/src/features/composer/components/Composer.tsx
index 574a7baf0..0e3769471 100644
--- a/src/features/composer/components/Composer.tsx
+++ b/src/features/composer/components/Composer.tsx
@@ -118,6 +118,13 @@ export function Composer({
   const textareaRef = externalTextareaRef ?? internalRef;
   const isDictationBusy = dictationState !== "idle";
   const canSend = text.trim().length > 0 || attachedImages.length > 0;
+  const isMac =
+    typeof navigator !== "undefined" &&
+    ((navigator as Navigator & { userAgentData?: { platform?: string } })
+      .userAgentData?.platform ?? navigator.platform ?? "")
+      .toLowerCase()
+      .includes("mac");
+  const sendShortcutLabel = isMac ? "⌘+Enter" : "Ctrl+Enter";
 
   useEffect(() => {
     setText((prev) => (prev === draftText ? prev : draftText));
@@ -244,6 +251,7 @@ export function Composer({
         canStop={canStop}
         canSend={canSend}
         isProcessing={isProcessing}
+        sendShortcutLabel={sendShortcutLabel}
         onStop={onStop}
         onSend={handleSend}
         dictationEnabled={dictationEnabled}
@@ -262,7 +270,9 @@ export function Composer({
         onTextChange={handleTextChange}
         onSelectionChange={handleSelectionChange}
         onKeyDown={(event) => {
-          if (event.key === "Enter" && event.shiftKey) {
+          const isEnter = event.key === "Enter";
+          const isSendShortcut = isMac ? event.metaKey : event.ctrlKey;
+          if (isEnter && !isSendShortcut) {
             event.preventDefault();
             const textarea = textareaRef.current;
             if (!textarea) {
@@ -295,7 +305,7 @@ export function Composer({
           if (event.defaultPrevented) {
             return;
           }
-          if (event.key === "Enter" && !event.shiftKey) {
+          if (isEnter && isSendShortcut) {
             if (isDictationBusy) {
               event.preventDefault();
               return;
diff --git a/src/features/composer/components/ComposerInput.tsx b/src/features/composer/components/ComposerInput.tsx
index 13cd983e9..e9f239278 100644
--- a/src/features/composer/components/ComposerInput.tsx
+++ b/src/features/composer/components/ComposerInput.tsx
@@ -13,6 +13,7 @@ type ComposerInputProps = {
   canStop: boolean;
   canSend: boolean;
   isProcessing: boolean;
+  sendShortcutLabel: string;
   onStop: () => void;
   onSend: () => void;
   dictationState?: "idle" | "listening" | "processing";
@@ -46,6 +47,7 @@ export function ComposerInput({
   canStop,
   canSend,
   isProcessing,
+  sendShortcutLabel,
   onStop,
   onSend,
   dictationState = "idle",
@@ -317,33 +319,38 @@ export function ComposerInput({
       >
         {isDictating ? <Square aria-hidden /> : <Mic aria-hidden />}
       </button>
-      <button
-        className={`composer-action${canStop ? " is-stop" : " is-send"}${
-          canStop && isProcessing ? " is-loading" : ""
-        }`}
-        onClick={handleActionClick}
-        disabled={disabled || isDictationBusy || (!canStop && !canSend)}
-        aria-label={canStop ? "Stop" : sendLabel}
+      <span
+        className="composer-action-wrap"
+        data-tooltip={canStop ? "Stop" : `Send (${sendShortcutLabel})`}
       >
-        {canStop ? (
-          <>
-            <span className="composer-action-stop-square" aria-hidden />
-            {isProcessing && (
-              <span className="composer-action-spinner" aria-hidden />
-            )}
-          </>
-        ) : (
-          <svg viewBox="0 0 24 24" fill="none" aria-hidden>
-            <path
-              d="M12 5l6 6m-6-6L6 11m6-6v14"
-              stroke="currentColor"
-              strokeWidth="1.7"
-              strokeLinecap="round"
-              strokeLinejoin="round"
-            />
-          </svg>
-        )}
-      </button>
+        <button
+          className={`composer-action${canStop ? " is-stop" : " is-send"}${
+            canStop && isProcessing ? " is-loading" : ""
+          }`}
+          onClick={handleActionClick}
+          disabled={disabled || isDictationBusy || (!canStop && !canSend)}
+          aria-label={canStop ? "Stop" : sendLabel}
+        >
+          {canStop ? (
+            <>
+              <span className="composer-action-stop-square" aria-hidden />
+              {isProcessing && (
+                <span className="composer-action-spinner" aria-hidden />
+              )}
+            </>
+          ) : (
+            <svg viewBox="0 0 24 24" fill="none" aria-hidden>
+              <path
+                d="M12 5l6 6m-6-6L6 11m6-6v14"
+                stroke="currentColor"
+                strokeWidth="1.7"
+                strokeLinecap="round"
+                strokeLinejoin="round"
+              />
+            </svg>
+          )}
+        </button>
+      </span>
     </div>
   );
 }
diff --git a/src/styles/composer.css b/src/styles/composer.css
index 95ba08f57..311f15f51 100644
--- a/src/styles/composer.css
+++ b/src/styles/composer.css
@@ -198,6 +198,35 @@
   position: relative;
 }
 
+.composer-action-wrap {
+  display: inline-flex;
+  position: relative;
+}
+
+.composer-action-wrap::after {
+  content: attr(data-tooltip);
+  position: absolute;
+  left: 50%;
+  bottom: calc(100% + 6px);
+  transform: translateX(-50%) translateY(4px);
+  padding: 4px 8px;
+  border-radius: 999px;
+  font-size: 10px;
+  color: var(--text-emphasis);
+  background: var(--surface-command);
+  border: 1px solid var(--border-subtle);
+  white-space: nowrap;
+  opacity: 0;
+  pointer-events: none;
+  transition: opacity 120ms ease, transform 120ms ease;
+  z-index: 2;
+}
+
+.composer-action-wrap:hover::after {
+  opacity: 1;
+  transform: translateX(-50%) translateY(0);
+}
+
 .composer-action--mic.is-active {
   border-color: rgba(120, 235, 190, 0.6);
   background: rgba(120, 235, 190, 0.12);