diff --git a/src/logging/logger.browser-import.test.ts b/src/logging/logger.browser-import.test.ts
new file mode 100644
index 00000000000..5704770d3ed
--- /dev/null
+++ b/src/logging/logger.browser-import.test.ts
@@ -0,0 +1,70 @@
+import { afterEach, describe, expect, it, vi } from "vitest";
+
+type LoggerModule = typeof import("./logger.js");
+
+const originalGetBuiltinModule = (
+  process as NodeJS.Process & { getBuiltinModule?: (id: string) => unknown }
+).getBuiltinModule;
+
+async function importBrowserSafeLogger(params?: {
+  resolvePreferredOpenClawTmpDir?: ReturnType<typeof vi.fn>;
+}): Promise<{
+  module: LoggerModule;
+  resolvePreferredOpenClawTmpDir: ReturnType<typeof vi.fn>;
+}> {
+  vi.resetModules();
+  const resolvePreferredOpenClawTmpDir =
+    params?.resolvePreferredOpenClawTmpDir ??
+    vi.fn(() => {
+      throw new Error("resolvePreferredOpenClawTmpDir should not run during browser-safe import");
+    });
+
+  vi.doMock("../infra/tmp-openclaw-dir.js", async () => {
+    const actual = await vi.importActual<typeof import("../infra/tmp-openclaw-dir.js")>(
+      "../infra/tmp-openclaw-dir.js",
+    );
+    return {
+      ...actual,
+      resolvePreferredOpenClawTmpDir,
+    };
+  });
+
+  Object.defineProperty(process, "getBuiltinModule", {
+    configurable: true,
+    value: undefined,
+  });
+
+  const module = await import("./logger.js");
+  return { module, resolvePreferredOpenClawTmpDir };
+}
+
+describe("logging/logger browser-safe import", () => {
+  afterEach(() => {
+    vi.resetModules();
+    vi.doUnmock("../infra/tmp-openclaw-dir.js");
+    Object.defineProperty(process, "getBuiltinModule", {
+      configurable: true,
+      value: originalGetBuiltinModule,
+    });
+  });
+
+  it("does not resolve the preferred temp dir at import time when node fs is unavailable", async () => {
+    const { module, resolvePreferredOpenClawTmpDir } = await importBrowserSafeLogger();
+
+    expect(resolvePreferredOpenClawTmpDir).not.toHaveBeenCalled();
+    expect(module.DEFAULT_LOG_DIR).toBe("/tmp/openclaw");
+    expect(module.DEFAULT_LOG_FILE).toBe("/tmp/openclaw/openclaw.log");
+  });
+
+  it("disables file logging when imported in a browser-like environment", async () => {
+    const { module, resolvePreferredOpenClawTmpDir } = await importBrowserSafeLogger();
+
+    expect(module.getResolvedLoggerSettings()).toMatchObject({
+      level: "silent",
+      file: "/tmp/openclaw/openclaw.log",
+    });
+    expect(module.isFileLogLevelEnabled("info")).toBe(false);
+    expect(() => module.getLogger().info("browser-safe")).not.toThrow();
+    expect(resolvePreferredOpenClawTmpDir).not.toHaveBeenCalled();
+  });
+});
diff --git a/src/logging/logger.ts b/src/logging/logger.ts
index 47e5624dc20..d73009fc696 100644
--- a/src/logging/logger.ts
+++ b/src/logging/logger.ts
@@ -3,7 +3,10 @@ import path from "node:path";
 import { Logger as TsLogger } from "tslog";
 import { getCommandPathWithRootOptions } from "../cli/argv.js";
 import type { OpenClawConfig } from "../config/types.js";
-import { resolvePreferredOpenClawTmpDir } from "../infra/tmp-openclaw-dir.js";
+import {
+  POSIX_OPENCLAW_TMP_DIR,
+  resolvePreferredOpenClawTmpDir,
+} from "../infra/tmp-openclaw-dir.js";
 import { readLoggingConfig } from "./config.js";
 import type { ConsoleStyle } from "./console.js";
 import { resolveEnvLogLevelOverride } from "./env-log-level.js";
@@ -12,7 +15,27 @@ import { resolveNodeRequireFromMeta } from "./node-require.js";
 import { loggingState } from "./state.js";
 import { formatLocalIsoWithOffset } from "./timestamps.js";
 
-export const DEFAULT_LOG_DIR = resolvePreferredOpenClawTmpDir();
+type ProcessWithBuiltinModule = NodeJS.Process & {
+  getBuiltinModule?: (id: string) => unknown;
+};
+
+function canUseNodeFs(): boolean {
+  const getBuiltinModule = (process as ProcessWithBuiltinModule).getBuiltinModule;
+  if (typeof getBuiltinModule !== "function") {
+    return false;
+  }
+  try {
+    return getBuiltinModule("fs") !== undefined;
+  } catch {
+    return false;
+  }
+}
+
+function resolveDefaultLogDir(): string {
+  return canUseNodeFs() ? resolvePreferredOpenClawTmpDir() : POSIX_OPENCLAW_TMP_DIR;
+}
+
+export const DEFAULT_LOG_DIR = resolveDefaultLogDir();
 export const DEFAULT_LOG_FILE = path.join(DEFAULT_LOG_DIR, "openclaw.log"); // legacy single-file path
 
 const LOG_PREFIX = "openclaw";
@@ -71,6 +94,14 @@ function canUseSilentVitestFileLogFastPath(envLevel: LogLevel | undefined): bool
 }
 
 function resolveSettings(): ResolvedSettings {
+  if (!canUseNodeFs()) {
+    return {
+      level: "silent",
+      file: DEFAULT_LOG_FILE,
+      maxFileBytes: DEFAULT_MAX_LOG_FILE_BYTES,
+    };
+  }
+
   const envLevel = resolveEnvLogLevelOverride();
   // Test runs default file logs to silent. Skip config reads and fallback load in the
   // common case to avoid pulling heavy config/schema stacks on startup.