diff --git a/web/scripts/analytics.test.mjs b/web/scripts/analytics.test.mjs
index 09671b7..cccf52f 100644
--- a/web/scripts/analytics.test.mjs
+++ b/web/scripts/analytics.test.mjs
@@ -143,3 +143,15 @@ test("the built pages do not fetch posthog-js up front", async () => {
     }
   }
 });
+
+test("errors leave the browser", () => {
+  // The other silent break: turn this off and the site keeps working, the
+  // console keeps logging, and the exception stream just stops. main.ts's
+  // trap renders the recovery screen but reports nothing off-box; this option
+  // is the only thing that does.
+  assert.match(
+    analytics,
+    /capture_exceptions:\s*true/,
+    "exception capture is off - crashes in the field are invisible again",
+  );
+});
diff --git a/web/src/analytics.ts b/web/src/analytics.ts
index 323adb1..dd362d4 100644
--- a/web/src/analytics.ts
+++ b/web/src/analytics.ts
@@ -121,6 +121,15 @@ export async function mountAnalytics(): Promise<void> {
     // for every stranger who reads one blog post. Signing in is what creates
     // one, in identify() below.
     person_profiles: "identified_only",
+
+    // Escaped errors and unhandled rejections leave the browser as $exception
+    // events. Until this, a crash in the field was a console.error in a tab
+    // nobody was looking at - main.ts's trap renders the recovery screen, but
+    // nothing off-box ever heard about it. PostHog's listeners see the same
+    // two channels the trap does, on every page the layout mounts, blog
+    // included. Free to 100k exceptions a month, and a runaway error loop is
+    // one page's session at a time, not the site multiplying pageviews.
+    capture_exceptions: true,
   });
 
   ph = posthog;