diff --git a/apps/journal/app/entry.server.tsx b/apps/journal/app/entry.server.tsx
index e7df39c..01dbf3d 100644
--- a/apps/journal/app/entry.server.tsx
+++ b/apps/journal/app/entry.server.tsx
@@ -15,6 +15,12 @@ Sentry.init({
   environment: sentryEnvironment,
   tracesSampleRate: 1.0,
   enabled: process.env.NODE_ENV === "production" && !process.env.CI,
+  beforeSend(event) {
+    // Drop 404s — they're expected (scanners, typos), not bugs
+    const serialized = event.extra?.__serialized__ as Record<string, unknown> | undefined;
+    if (serialized?.status === 404) return null;
+    return event;
+  },
 });
 
 export const streamTimeout = 5_000;
diff --git a/apps/journal/app/root.tsx b/apps/journal/app/root.tsx
index fb07974..cdd85c1 100644
--- a/apps/journal/app/root.tsx
+++ b/apps/journal/app/root.tsx
@@ -123,7 +123,10 @@ export default function App({ loaderData }: Route.ComponentProps) {
 }
 
 export function ErrorBoundary({ error }: Route.ErrorBoundaryProps) {
-  Sentry.captureException(error);
+  // Don't report expected HTTP errors (404, 403) to Sentry
+  if (!(isRouteErrorResponse(error) && error.status < 500)) {
+    Sentry.captureException(error);
+  }
   const { t } = useTranslation();
 
   if (isRouteErrorResponse(error)) {
diff --git a/apps/planner/app/root.tsx b/apps/planner/app/root.tsx
index ff708ce..ec78097 100644
--- a/apps/planner/app/root.tsx
+++ b/apps/planner/app/root.tsx
@@ -33,7 +33,9 @@ export default function App() {
 }
 
 export function ErrorBoundary({ error }: Route.ErrorBoundaryProps) {
-  Sentry.captureException(error);
+  if (!(isRouteErrorResponse(error) && error.status < 500)) {
+    Sentry.captureException(error);
+  }
   const { t } = useTranslation();
 
   if (isRouteErrorResponse(error)) {
diff --git a/apps/planner/server.ts b/apps/planner/server.ts
index d4cfc93..aaa4121 100644
--- a/apps/planner/server.ts
+++ b/apps/planner/server.ts
@@ -13,6 +13,11 @@ Sentry.init({
   environment: sentryEnvironment,
   tracesSampleRate: 1.0,
   enabled: process.env.NODE_ENV === "production" && !process.env.CI,
+  beforeSend(event) {
+    const serialized = event.extra?.__serialized__ as Record<string, unknown> | undefined;
+    if (serialized?.status === 404) return null;
+    return event;
+  },
 });
 
 const port = Number(process.env.PORT ?? 3001);