diff --git a/tests/e2e-mobile/fixtures.ts b/tests/e2e-mobile/fixtures.ts
index 033e38e..d040e04 100644
--- a/tests/e2e-mobile/fixtures.ts
+++ b/tests/e2e-mobile/fixtures.ts
@@ -1,5 +1,6 @@
 import type { Page } from "@playwright/test"
 import { test as base, expect as pwExpect } from "@playwright/test"
+import { attachConsoleMonitor } from "../fixtures/console-monitor"
 
 export { expect, type Page, API_BASE, clickSpaLink } from "../e2e/fixtures"
 import { expect } from "../e2e/fixtures"
@@ -11,6 +12,8 @@ export const test = base.extend<MobileFixtures>({
      * Override page fixture: BrowserSync domcontentloaded workaround.
      */
     page: async ({ page }, use) => {
+        const monitor = attachConsoleMonitor(page)
+
         const origGoto = page.goto.bind(page)
         const origReload = page.reload.bind(page)
 
@@ -19,6 +22,7 @@ export const test = base.extend<MobileFixtures>({
         page.reload = ((opts?: any) => origReload({ waitUntil: "domcontentloaded", ...opts })) as typeof page.reload
 
         await use(page)
+        monitor.assertNoErrors()
     },
 })
 
diff --git a/tests/e2e-visual/fixtures.ts b/tests/e2e-visual/fixtures.ts
index 3c7fb1a..81a2c6f 100644
--- a/tests/e2e-visual/fixtures.ts
+++ b/tests/e2e-visual/fixtures.ts
@@ -1,5 +1,6 @@
 import type { Page, Locator } from "@playwright/test"
 import { test as base, expect as pwExpect } from "@playwright/test"
+import { attachConsoleMonitor } from "../fixtures/console-monitor"
 
 export { expect, type Page, API_BASE, clickSpaLink } from "../e2e/fixtures"
 import { expect } from "../e2e/fixtures"
@@ -11,6 +12,8 @@ export const test = base.extend<VisualFixtures>({
      * Override page fixture: BrowserSync domcontentloaded workaround.
      */
     page: async ({ page }, use) => {
+        const monitor = attachConsoleMonitor(page)
+
         const origGoto = page.goto.bind(page)
         const origReload = page.reload.bind(page)
 
@@ -19,6 +22,7 @@ export const test = base.extend<VisualFixtures>({
         page.reload = ((opts?: any) => origReload({ waitUntil: "domcontentloaded", ...opts })) as typeof page.reload
 
         await use(page)
+        monitor.assertNoErrors()
     },
 })
 
diff --git a/tests/e2e/fixtures.ts b/tests/e2e/fixtures.ts
index 213678f..3d229e0 100644
--- a/tests/e2e/fixtures.ts
+++ b/tests/e2e/fixtures.ts
@@ -1,5 +1,6 @@
 import { test as base, expect, type Page } from "@playwright/test"
 import { ensureTestUser, type TestUserCredentials } from "../api/helpers/test-user"
+import { attachConsoleMonitor } from "../fixtures/console-monitor"
 
 const API_BASE = "/api"
 
@@ -29,6 +30,8 @@ export const test = base.extend<E2eFixtures, E2eWorkerFixtures>({
      * navigation methods to "domcontentloaded".
      */
     page: async ({ page }, use) => {
+        const monitor = attachConsoleMonitor(page)
+
         const origGoto = page.goto.bind(page)
         const origReload = page.reload.bind(page)
         const origGoBack = page.goBack.bind(page)
@@ -42,6 +45,7 @@ export const test = base.extend<E2eFixtures, E2eWorkerFixtures>({
             origGoForward({ waitUntil: "domcontentloaded", ...opts })) as typeof page.goForward
 
         await use(page)
+        monitor.assertNoErrors()
     },
 
     // Worker-scoped: create/reuse test user once per worker
diff --git a/tests/fixtures/console-monitor.ts b/tests/fixtures/console-monitor.ts
new file mode 100644
index 0000000..8a0b0c6
--- /dev/null
+++ b/tests/fixtures/console-monitor.ts
@@ -0,0 +1,117 @@
+/**
+ * Console/Network-Error-Monitor für Playwright-Tests.
+ *
+ * Überwacht Browser-Pages auf:
+ * - `pageerror`      – Uncaught Exceptions
+ * - `console.error`  – Alle console.error()-Aufrufe
+ * - `requestfailed`  – Fehlgeschlagene Netzwerk-Requests (nicht absichtlich abgebrochene)
+ *
+ * Verwendung in Fixtures:
+ * ```ts
+ * const monitor = attachConsoleMonitor(page)
+ * // … setup …
+ * await use(page)
+ * monitor.assertNoErrors()
+ * ```
+ *
+ * Fehler werden NICHT ignoriert, sondern in der App gefixt.
+ * IGNORED_PATTERNS nur für Infrastructure-Rauschen, das nicht in der App liegt.
+ */
+
+import type { Page } from "@playwright/test"
+
+// ── Whitelist (nur Infrastructure-Rauschen, keine App-Fehler) ────────
+
+const IGNORED_PATTERNS: RegExp[] = [
+    /browser-sync/i,
+    /cc\.webmakers\.de/i,
+    /sentry/i,
+    /Failed to load resource: net::ERR_/i,
+    /Failed to load resource: the server responded with a status of/i,
+    /TypeError: Failed to fetch/i,
+]
+
+// ── Types ────────────────────────────────────────────────────────────
+
+interface ConsoleError {
+    type: "pageerror" | "console.error" | "request-failed"
+    message: string
+}
+
+export interface ConsoleMonitor {
+    getErrors(): ConsoleError[]
+    assertNoErrors(): void
+}
+
+// ── Implementation ───────────────────────────────────────────────────
+
+function isIgnored(text: string): boolean {
+    return IGNORED_PATTERNS.some((pattern) => pattern.test(text))
+}
+
+export function attachConsoleMonitor(page: Page): ConsoleMonitor {
+    const errors: ConsoleError[] = []
+
+    // Inject script to capture detailed unhandled rejection info
+    page.addInitScript(() => {
+        window.addEventListener("unhandledrejection", (event) => {
+            const reason = event.reason
+            if (reason && typeof reason === "object" && !(reason instanceof Error)) {
+                try {
+                    const detail = JSON.stringify(
+                        reason,
+                        (_key, val) => {
+                            if (val instanceof Response) return `[Response ${val.status} ${val.url}]`
+                            if (val instanceof Request) return `[Request ${val.method} ${val.url}]`
+                            return val
+                        },
+                        2
+                    )
+                    console.error(`[unhandled-rejection-detail] ${detail}`)
+                } catch {
+                    console.error(`[unhandled-rejection-detail] ${String(reason)}`)
+                }
+            }
+        })
+    })
+
+    page.on("pageerror", (error) => {
+        const msg = error.stack || error.message || String(error)
+        if (!isIgnored(msg)) {
+            errors.push({ type: "pageerror", message: msg })
+        }
+    })
+
+    page.on("console", (msg) => {
+        if (msg.type() === "error") {
+            const text = msg.text()
+            if (!isIgnored(text)) {
+                errors.push({ type: "console.error", message: text })
+            }
+        }
+    })
+
+    page.on("requestfailed", (request) => {
+        const failure = request.failure()?.errorText || "unknown"
+        if (failure === "net::ERR_ABORTED" || failure === "net::ERR_FAILED") return
+        const url = request.url()
+        if (isIgnored(url)) return
+        errors.push({
+            type: "request-failed",
+            message: `${request.method()} ${url} – ${failure}`,
+        })
+    })
+
+    return {
+        getErrors: () => [...errors],
+        assertNoErrors() {
+            if (errors.length > 0) {
+                const summary = errors.map((e) => `  [${e.type}] ${e.message}`).join("\n")
+                throw new Error(
+                    `Browser-Fehler während des Tests erkannt (${errors.length}):\n${summary}\n\n` +
+                        `→ Fehler in der App fixen, NICHT in IGNORED_PATTERNS aufnehmen!`
+                )
+            }
+        },
+    }
+}