diff --git a/app/src/pages/conversations/composerSendDecision.test.ts b/app/src/pages/conversations/composerSendDecision.test.ts
index abbfa0157..66723ba68 100644
--- a/app/src/pages/conversations/composerSendDecision.test.ts
+++ b/app/src/pages/conversations/composerSendDecision.test.ts
@@ -4,6 +4,7 @@ import {
   evaluateComposerSend,
   getComposerBlockedSendFeedback,
   handleComposerSlashCommand,
+  shouldSendComposerKeyDown,
 } from './composerSendDecision';
 
 describe('evaluateComposerSend', () => {
@@ -104,6 +105,30 @@ describe('handleComposerSlashCommand', () => {
   });
 });
 
+describe('shouldSendComposerKeyDown', () => {
+  it('allows Enter to send when IME composition is inactive', () => {
+    expect(shouldSendComposerKeyDown({ key: 'Enter' })).toBe(true);
+  });
+
+  it('does not send on Shift+Enter', () => {
+    expect(shouldSendComposerKeyDown({ key: 'Enter', shiftKey: true })).toBe(false);
+  });
+
+  it('does not send while React reports IME composition', () => {
+    expect(shouldSendComposerKeyDown({ key: 'Enter', nativeEvent: { isComposing: true } })).toBe(
+      false
+    );
+  });
+
+  it('does not send while the browser reports legacy IME keyCode 229', () => {
+    expect(shouldSendComposerKeyDown({ key: 'Enter', nativeEvent: { keyCode: 229 } })).toBe(false);
+  });
+
+  it('does not send while textarea composition state is active', () => {
+    expect(shouldSendComposerKeyDown({ key: 'Enter' }, true)).toBe(false);
+  });
+});
+
 describe('getComposerBlockedSendFeedback', () => {
   it('returns modal and error feedback for usage-limit blocking', () => {
     expect(getComposerBlockedSendFeedback('usage_limit_reached')).toEqual({
diff --git a/app/src/pages/conversations/composerSendDecision.ts b/app/src/pages/conversations/composerSendDecision.ts
index e6068b0d8..2f3b6abe0 100644
--- a/app/src/pages/conversations/composerSendDecision.ts
+++ b/app/src/pages/conversations/composerSendDecision.ts
@@ -28,6 +28,14 @@ export interface ComposerBlockedSendFeedback {
   error: { code: 'usage_limit_reached' | 'socket_disconnected'; message: string };
 }
 
+export interface ComposerKeyDownEventLike {
+  key: string;
+  shiftKey?: boolean;
+  isComposing?: boolean;
+  keyCode?: number;
+  nativeEvent?: { isComposing?: boolean; keyCode?: number };
+}
+
 export const handleComposerSlashCommand = (
   command: string,
   welcomeLocked: boolean
@@ -65,6 +73,22 @@ export const evaluateComposerSend = (args: ComposerSendDecisionArgs): ComposerSe
   return { shouldSend: true, trimmedText };
 };
 
+export const isComposerImeComposing = (
+  event: ComposerKeyDownEventLike,
+  compositionActive = false
+): boolean =>
+  compositionActive ||
+  event.isComposing === true ||
+  event.keyCode === 229 ||
+  event.nativeEvent?.isComposing === true ||
+  event.nativeEvent?.keyCode === 229;
+
+export const shouldSendComposerKeyDown = (
+  event: ComposerKeyDownEventLike,
+  compositionActive = false
+): boolean =>
+  event.key === 'Enter' && !event.shiftKey && !isComposerImeComposing(event, compositionActive);
+
 export const getComposerBlockedSendFeedback = (
   blockReason: ComposerSendBlockReason | undefined
 ): ComposerBlockedSendFeedback | null => {