diff --git a/CHANGELOG.md b/CHANGELOG.md
index a39003f644e..6566329a641 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -16,6 +16,8 @@ Docs: https://docs.openclaw.ai
 
 - Browser/Playwright: ignore benign already-handled route races during guarded navigation so browser-page tasks no longer fail when Playwright tears down a route mid-flight. (#68708) Thanks @Steady-ai.
 - Browser/Linux: detect Chromium-based installs under `/opt/google`, `/opt/brave.com`, `/usr/lib/chromium`, and `/usr/lib/chromium-browser` before asking users to set `browser.executablePath`. (#48563) Thanks @lupuletic.
+- Sessions/browser: close tracked browser tabs when idle, daily, `/new`, or `/reset` session rollover archives the previous transcript, preventing tabs from leaking past the old session. Thanks @jakozloski.
+- Sessions/forking: fall back to transcript-estimated parent token counts when cached totals are stale or missing, so oversized thread forks start fresh instead of cloning the full parent transcript. Thanks @jalehman.
 - MCP/CLI: retire bundled MCP runtimes at the end of one-shot `openclaw agent` and `openclaw infer model run` gateway/local executions, so repeated scripted runs do not accumulate stdio MCP child processes. Fixes #71457.
 - OpenAI/Codex image generation: canonicalize legacy `openai-codex.baseUrl` values such as `https://chatgpt.com/backend-api` to the Codex Responses backend before calling `gpt-image-2`, matching the chat transport. Fixes #71460.
 - Control UI: make `/usage` use the fresh context snapshot for context percentage, and include cache-write tokens in the Usage overview cache-hit denominator. Fixes #47885. Thanks @imwyvern and @Ante042.
diff --git a/src/auto-reply/reply/session-fork.runtime.test.ts b/src/auto-reply/reply/session-fork.runtime.test.ts
new file mode 100644
index 00000000000..3f4e4432cc3
--- /dev/null
+++ b/src/auto-reply/reply/session-fork.runtime.test.ts
@@ -0,0 +1,73 @@
+import fs from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import type { SessionEntry } from "../../config/sessions/types.js";
+import { resolveParentForkTokenCountRuntime } from "./session-fork.runtime.js";
+
+const roots: string[] = [];
+
+async function makeRoot(prefix: string): Promise<string> {
+  const root = await fs.mkdtemp(path.join(os.tmpdir(), prefix));
+  roots.push(root);
+  return root;
+}
+
+afterEach(async () => {
+  await Promise.all(roots.splice(0).map((root) => fs.rm(root, { recursive: true, force: true })));
+});
+
+describe("resolveParentForkTokenCountRuntime", () => {
+  it("falls back to transcript-estimated tokens when cached totals are stale", async () => {
+    const root = await makeRoot("openclaw-parent-fork-token-estimate-");
+    const sessionsDir = path.join(root, "sessions");
+    await fs.mkdir(sessionsDir);
+
+    const sessionId = "parent-overflow-transcript";
+    const sessionFile = path.join(sessionsDir, "parent.jsonl");
+    const lines = [
+      JSON.stringify({
+        type: "session",
+        version: 3,
+        id: sessionId,
+        timestamp: new Date().toISOString(),
+        cwd: process.cwd(),
+      }),
+    ];
+    for (let index = 0; index < 40; index += 1) {
+      const body = `turn-${index} ${"x".repeat(12_000)}`;
+      lines.push(
+        JSON.stringify({
+          type: "message",
+          id: `u${index}`,
+          parentId: index === 0 ? null : `a${index - 1}`,
+          timestamp: new Date().toISOString(),
+          message: { role: "user", content: body },
+        }),
+        JSON.stringify({
+          type: "message",
+          id: `a${index}`,
+          parentId: `u${index}`,
+          timestamp: new Date().toISOString(),
+          message: { role: "assistant", content: body },
+        }),
+      );
+    }
+    await fs.writeFile(sessionFile, `${lines.join("\n")}\n`, "utf-8");
+
+    const entry: SessionEntry = {
+      sessionId,
+      sessionFile,
+      updatedAt: Date.now(),
+      totalTokens: 1,
+      totalTokensFresh: false,
+    };
+
+    const tokens = resolveParentForkTokenCountRuntime({
+      parentEntry: entry,
+      storePath: path.join(root, "sessions.json"),
+    });
+
+    expect(tokens).toBeGreaterThan(100_000);
+  });
+});
diff --git a/src/auto-reply/reply/session-fork.runtime.ts b/src/auto-reply/reply/session-fork.runtime.ts
index 736a1a7792c..96ceafe71a1 100644
--- a/src/auto-reply/reply/session-fork.runtime.ts
+++ b/src/auto-reply/reply/session-fork.runtime.ts
@@ -1,9 +1,49 @@
 import crypto from "node:crypto";
 import fs from "node:fs";
 import path from "node:path";
+import type { AgentMessage } from "@mariozechner/pi-agent-core";
 import { CURRENT_SESSION_VERSION, SessionManager } from "@mariozechner/pi-coding-agent";
+import { estimateMessagesTokens } from "../../agents/compaction.js";
 import { resolveSessionFilePath } from "../../config/sessions/paths.js";
-import type { SessionEntry } from "../../config/sessions/types.js";
+import { resolveFreshSessionTotalTokens, type SessionEntry } from "../../config/sessions/types.js";
+import { readSessionMessages } from "../../gateway/session-utils.fs.js";
+
+function resolvePositiveTokenCount(value: number | undefined): number | undefined {
+  return typeof value === "number" && Number.isFinite(value) && value > 0
+    ? Math.floor(value)
+    : undefined;
+}
+
+export function resolveParentForkTokenCountRuntime(params: {
+  parentEntry: SessionEntry;
+  storePath: string;
+}): number | undefined {
+  const freshPersistedTokens = resolveFreshSessionTotalTokens(params.parentEntry);
+  if (typeof freshPersistedTokens === "number") {
+    return freshPersistedTokens;
+  }
+
+  try {
+    const transcriptMessages = readSessionMessages(
+      params.parentEntry.sessionId,
+      params.storePath,
+      params.parentEntry.sessionFile,
+    ) as AgentMessage[];
+    if (transcriptMessages.length > 0) {
+      const estimatedTokens = estimateMessagesTokens(transcriptMessages);
+      const transcriptTokens = resolvePositiveTokenCount(
+        Number.isFinite(estimatedTokens) ? Math.ceil(estimatedTokens) : undefined,
+      );
+      if (typeof transcriptTokens === "number") {
+        return transcriptTokens;
+      }
+    }
+  } catch {
+    // Fall back to cached totals when the parent transcript cannot be read.
+  }
+
+  return resolvePositiveTokenCount(params.parentEntry.totalTokens);
+}
 
 export function forkSessionFromParentRuntime(params: {
   parentEntry: SessionEntry;
diff --git a/src/auto-reply/reply/session-fork.ts b/src/auto-reply/reply/session-fork.ts
index 1090c046456..cdd3ecaf30a 100644
--- a/src/auto-reply/reply/session-fork.ts
+++ b/src/auto-reply/reply/session-fork.ts
@@ -30,3 +30,11 @@ export async function forkSessionFromParent(params: {
   const runtime = await loadSessionForkRuntime();
   return runtime.forkSessionFromParentRuntime(params);
 }
+
+export async function resolveParentForkTokenCount(params: {
+  parentEntry: SessionEntry;
+  storePath: string;
+}): Promise<number | undefined> {
+  const runtime = await loadSessionForkRuntime();
+  return runtime.resolveParentForkTokenCountRuntime(params);
+}
diff --git a/src/auto-reply/reply/session.test.ts b/src/auto-reply/reply/session.test.ts
index bad125b0cc4..661a2438ae2 100644
--- a/src/auto-reply/reply/session.test.ts
+++ b/src/auto-reply/reply/session.test.ts
@@ -28,11 +28,15 @@ import { initSessionState } from "./session.js";
 
 const sessionForkMocks = vi.hoisted(() => ({
   forkSessionFromParent: vi.fn(),
+  resolveParentForkTokenCount: vi.fn(),
   nextSessionId: 0,
 }));
 const channelSummaryMocks = vi.hoisted(() => ({
   buildChannelSummary: vi.fn(async () => [] as string[]),
 }));
+const browserMaintenanceMocks = vi.hoisted(() => ({
+  closeTrackedBrowserTabsForSessions: vi.fn(async () => 0),
+}));
 
 type ForkSessionParamsForTest = {
   parentEntry: SessionEntry;
@@ -42,6 +46,8 @@ type ForkSessionParamsForTest = {
 vi.mock("./session-fork.js", () => ({
   forkSessionFromParent: (...args: [ForkSessionParamsForTest]) =>
     sessionForkMocks.forkSessionFromParent(...args),
+  resolveParentForkTokenCount: (...args: [{ parentEntry: SessionEntry; storePath: string }]) =>
+    sessionForkMocks.resolveParentForkTokenCount(...args),
   resolveParentForkMaxTokens: (cfg: { session?: { parentForkMaxTokens?: unknown } }) => {
     const configured = cfg.session?.parentForkMaxTokens;
     return typeof configured === "number" && Number.isFinite(configured) && configured >= 0
@@ -50,6 +56,10 @@ vi.mock("./session-fork.js", () => ({
   },
 }));
 
+vi.mock("../../plugin-sdk/browser-maintenance.js", () => ({
+  closeTrackedBrowserTabsForSessions: browserMaintenanceMocks.closeTrackedBrowserTabsForSessions,
+}));
+
 vi.mock("../../plugins/hook-runner-global.js", () => ({
   getGlobalHookRunner: () => null,
 }));
@@ -248,8 +258,15 @@ function registerCurrentConversationBindingAdapterForTest(params: {
 
 beforeEach(() => {
   channelSummaryMocks.buildChannelSummary.mockReset().mockResolvedValue([]);
+  browserMaintenanceMocks.closeTrackedBrowserTabsForSessions.mockReset().mockResolvedValue(0);
   sessionBindingTesting.resetSessionBindingAdaptersForTests();
   sessionForkMocks.nextSessionId = 0;
+  sessionForkMocks.resolveParentForkTokenCount.mockReset().mockImplementation(({ parentEntry }) => {
+    const tokens = parentEntry.totalTokens;
+    return typeof tokens === "number" && Number.isFinite(tokens) && tokens > 0
+      ? Math.floor(tokens)
+      : undefined;
+  });
   sessionForkMocks.forkSessionFromParent
     .mockReset()
     .mockImplementation(async ({ parentEntry, sessionsDir }: ForkSessionParamsForTest) => {
@@ -517,6 +534,66 @@ describe("initSessionState thread forking", () => {
     expect(result.sessionEntry.sessionFile).not.toBe(parentSessionFile);
   });
 
+  it("skips fork when resolved parent token estimate exceeds threshold", async () => {
+    const root = await makeCaseDir("openclaw-thread-session-overflow-estimated-");
+    const sessionsDir = path.join(root, "sessions");
+    await fs.mkdir(sessionsDir);
+
+    const parentSessionId = "parent-overflow-estimated";
+    const parentSessionFile = path.join(sessionsDir, "parent.jsonl");
+    await fs.writeFile(
+      parentSessionFile,
+      `${JSON.stringify({
+        type: "session",
+        version: 3,
+        id: parentSessionId,
+        timestamp: new Date().toISOString(),
+        cwd: process.cwd(),
+      })}\n`,
+      "utf-8",
+    );
+
+    const storePath = path.join(root, "sessions.json");
+    const parentSessionKey = "agent:main:slack:channel:c1";
+    await writeSessionStoreFast(storePath, {
+      [parentSessionKey]: {
+        sessionId: parentSessionId,
+        sessionFile: parentSessionFile,
+        updatedAt: Date.now(),
+        totalTokens: 1,
+        totalTokensFresh: false,
+      },
+    });
+    sessionForkMocks.resolveParentForkTokenCount.mockReturnValueOnce(170_000);
+
+    const cfg = {
+      session: { store: storePath },
+    } as OpenClawConfig;
+
+    const threadSessionKey = "agent:main:slack:channel:c1:thread:estimated";
+    const result = await initSessionState({
+      ctx: {
+        Body: "Thread reply",
+        SessionKey: threadSessionKey,
+        ParentSessionKey: parentSessionKey,
+      },
+      cfg,
+      commandAuthorized: true,
+    });
+
+    expect(sessionForkMocks.resolveParentForkTokenCount).toHaveBeenCalledWith({
+      parentEntry: expect.objectContaining({
+        sessionId: parentSessionId,
+        totalTokensFresh: false,
+      }),
+      storePath,
+    });
+    expect(result.sessionEntry.forkedFromParent).toBe(true);
+    expect(result.sessionEntry.sessionId).not.toBe(parentSessionId);
+    expect(result.sessionEntry.sessionFile).not.toBe(parentSessionFile);
+    expect(sessionForkMocks.forkSessionFromParent).not.toHaveBeenCalled();
+  });
+
   it("respects session.parentForkMaxTokens override", async () => {
     const root = await makeCaseDir("openclaw-thread-session-overflow-override-");
     const sessionsDir = path.join(root, "sessions");
@@ -1616,6 +1693,95 @@ describe("initSessionState reset policy", () => {
   });
 });
 
+describe("initSessionState browser tab cleanup", () => {
+  it("closes tracked browser tabs when idle session expires", async () => {
+    vi.setSystemTime(new Date(2026, 0, 18, 5, 30, 0));
+    const storePath = await createStorePath("openclaw-tab-cleanup-idle-");
+    const sessionKey = "agent:main:whatsapp:dm:tab-idle";
+    const existingSessionId = "tab-idle-session-id";
+
+    await writeSessionStoreFast(storePath, {
+      [sessionKey]: {
+        sessionId: existingSessionId,
+        updatedAt: new Date(2026, 0, 18, 4, 45, 0).getTime(),
+      },
+    });
+
+    const cfg = {
+      session: {
+        store: storePath,
+        reset: { mode: "daily", atHour: 4, idleMinutes: 30 },
+      },
+    } as OpenClawConfig;
+    const result = await initSessionState({
+      ctx: { Body: "hello", SessionKey: sessionKey },
+      cfg,
+      commandAuthorized: true,
+    });
+
+    expect(result.isNewSession).toBe(true);
+    expect(browserMaintenanceMocks.closeTrackedBrowserTabsForSessions).toHaveBeenCalledWith(
+      expect.objectContaining({
+        sessionKeys: expect.arrayContaining([existingSessionId, sessionKey]),
+      }),
+    );
+  });
+
+  it("closes tracked browser tabs on explicit /new reset", async () => {
+    const storePath = await createStorePath("openclaw-tab-cleanup-reset-");
+    const sessionKey = "agent:main:telegram:dm:tab-reset";
+    const existingSessionId = "tab-reset-session-id";
+
+    await writeSessionStoreFast(storePath, {
+      [sessionKey]: {
+        sessionId: existingSessionId,
+        updatedAt: Date.now(),
+      },
+    });
+
+    const cfg = {
+      session: { store: storePath, idleMinutes: 999 },
+    } as OpenClawConfig;
+    const result = await initSessionState({
+      ctx: {
+        Body: "/new",
+        RawBody: "/new",
+        CommandBody: "/new",
+        SessionKey: sessionKey,
+      },
+      cfg,
+      commandAuthorized: true,
+    });
+
+    expect(result.isNewSession).toBe(true);
+    expect(browserMaintenanceMocks.closeTrackedBrowserTabsForSessions).toHaveBeenCalledWith(
+      expect.objectContaining({
+        sessionKeys: expect.arrayContaining([existingSessionId, sessionKey]),
+      }),
+    );
+  });
+
+  it("does not close browser tabs for a fresh session without previous state", async () => {
+    const storePath = await createStorePath("openclaw-tab-cleanup-fresh-");
+    const sessionKey = "agent:main:telegram:dm:tab-fresh";
+
+    const cfg = {
+      session: { store: storePath, idleMinutes: 999 },
+    } as OpenClawConfig;
+    const result = await initSessionState({
+      ctx: {
+        Body: "hello",
+        SessionKey: sessionKey,
+      },
+      cfg,
+      commandAuthorized: true,
+    });
+
+    expect(result.isNewSession).toBe(true);
+    expect(browserMaintenanceMocks.closeTrackedBrowserTabsForSessions).not.toHaveBeenCalled();
+  });
+});
+
 describe("initSessionState channel reset overrides", () => {
   it("uses channel-specific reset policy when configured", async () => {
     const root = await makeCaseDir("openclaw-channel-idle-");
diff --git a/src/auto-reply/reply/session.ts b/src/auto-reply/reply/session.ts
index 3b56e4de97e..d703eb32243 100644
--- a/src/auto-reply/reply/session.ts
+++ b/src/auto-reply/reply/session.ts
@@ -35,6 +35,7 @@ import type { TtsAutoMode } from "../../config/types.tts.js";
 import { getSessionBindingService } from "../../infra/outbound/session-binding-service.js";
 import { deliverSessionMaintenanceWarning } from "../../infra/session-maintenance-warning.js";
 import { createSubsystemLogger } from "../../logging/subsystem.js";
+import { closeTrackedBrowserTabsForSessions } from "../../plugin-sdk/browser-maintenance.js";
 import { getGlobalHookRunner } from "../../plugins/hook-runner-global.js";
 import type { PluginHookSessionEndReason } from "../../plugins/hook-types.js";
 import { isAcpSessionKey, normalizeMainKey } from "../../routing/session-key.js";
@@ -58,7 +59,11 @@ import {
   resolveLastChannelRaw,
   resolveLastToRaw,
 } from "./session-delivery.js";
-import { forkSessionFromParent, resolveParentForkMaxTokens } from "./session-fork.js";
+import {
+  forkSessionFromParent,
+  resolveParentForkMaxTokens,
+  resolveParentForkTokenCount,
+} from "./session-fork.js";
 import { buildSessionEndHookPayload, buildSessionStartHookPayload } from "./session-hooks.js";
 
 const log = createSubsystemLogger("session-init");
@@ -678,8 +683,19 @@ export async function initSessionState(params: {
     sessionStore[parentSessionKey] &&
     !alreadyForked
   ) {
-    const parentTokens = sessionStore[parentSessionKey].totalTokens ?? 0;
-    if (parentForkMaxTokens > 0 && parentTokens > parentForkMaxTokens) {
+    const parentEntry = sessionStore[parentSessionKey];
+    const parentTokens =
+      parentForkMaxTokens > 0
+        ? await resolveParentForkTokenCount({
+            parentEntry,
+            storePath,
+          })
+        : undefined;
+    if (
+      parentForkMaxTokens > 0 &&
+      typeof parentTokens === "number" &&
+      parentTokens > parentForkMaxTokens
+    ) {
       // Parent context is too large — forking would create a thread session
       // that immediately overflows the model's context window. Start fresh
       // instead and mark as forked to prevent re-attempts. See #26905.
@@ -691,10 +707,10 @@ export async function initSessionState(params: {
     } else {
       log.warn(
         `forking from parent session: parentKey=${parentSessionKey} → sessionKey=${sessionKey} ` +
-          `parentTokens=${parentTokens}`,
+          `parentTokens=${parentTokens ?? "unknown"}`,
       );
       const forked = await forkSessionFromParent({
-        parentEntry: sessionStore[parentSessionKey],
+        parentEntry,
         agentId,
         sessionsDir: path.dirname(storePath),
       });
@@ -806,6 +822,12 @@ export async function initSessionState(params: {
       sessionFile: previousSessionEntry.sessionFile,
       reason: previousSessionEndReason ?? "unknown",
     });
+    void closeTrackedBrowserTabsForSessions({
+      sessionKeys: [previousSessionEntry.sessionId, sessionKey],
+      onWarn: (message) => log.warn(message),
+    }).catch((error) => {
+      log.warn(`browser tab cleanup failed: ${String(error)}`);
+    });
   }
 
   const sessionCtx: TemplateContext = {