diff --git a/src/browser.ts b/src/browser.ts
index 7deea75b4..d172e838e 100644
--- a/src/browser.ts
+++ b/src/browser.ts
@@ -20,6 +20,81 @@ import {puppeteer} from './third_party/index.js';
 
 let browser: Browser | undefined;
 
+// Multi-browser registry
+const browserRegistry = new Map<string, Browser>();
+let activeBrowserId = 'default';
+
+export function switchActiveBrowser(browserId: string): Browser {
+  if (!browserRegistry.has(browserId)) {
+    const available = [...browserRegistry.keys()];
+    if (available.length === 0) {
+      throw new Error(
+        `Browser '${browserId}' not found. No browsers are currently registered.`,
+      );
+    }
+    throw new Error(
+      `Browser '${browserId}' not found. Available browsers: ${available.join(', ')}`,
+    );
+  }
+  const targetBrowser = browserRegistry.get(browserId)!;
+  if (!targetBrowser?.connected) {
+    throw new Error(
+      `Browser '${browserId}' is disconnected. Remove it and add again with add_browser.`,
+    );
+  }
+  activeBrowserId = browserId;
+  browser = targetBrowser;
+  return browser;
+}
+
+export interface BrowserInfo {
+  id: string;
+  connected: boolean;
+  active: boolean;
+}
+
+export function listBrowsers(): BrowserInfo[] {
+  const result: BrowserInfo[] = [];
+  for (const [id, b] of browserRegistry.entries()) {
+    result.push({
+      id,
+      connected: b?.connected ?? false,
+      active: id === activeBrowserId,
+    });
+  }
+  return result;
+}
+
+export async function addBrowser(
+  browserId: string,
+  options: {browserURL?: string; wsEndpoint?: string; enableExtensions?: boolean},
+): Promise<Browser> {
+  const connectOptions: Parameters<typeof puppeteer.connect>[0] = {
+    targetFilter: makeTargetFilter(options.enableExtensions ?? false),
+    defaultViewport: null,
+    handleDevToolsAsPage: true,
+  };
+  if (options.browserURL) {
+    connectOptions.browserURL = options.browserURL;
+  } else if (options.wsEndpoint) {
+    connectOptions.browserWSEndpoint = options.wsEndpoint;
+  } else {
+    throw new Error('Either browserURL or wsEndpoint must be provided');
+  }
+  logger('Adding browser', browserId, JSON.stringify(connectOptions));
+  const newBrowser = await puppeteer.connect(connectOptions);
+  browserRegistry.set(browserId, newBrowser);
+  if (!browser || browserRegistry.size === 1) {
+    browser = newBrowser;
+    activeBrowserId = browserId;
+  }
+  return newBrowser;
+}
+
+export function getActiveBrowserId(): string {
+  return activeBrowserId;
+}
+
 function makeTargetFilter(enableExtensions = false) {
   const ignoredPrefixes = new Set(['chrome://', 'chrome-untrusted://']);
   if (!enableExtensions) {
@@ -130,6 +205,7 @@ export async function ensureBrowserConnected(options: {
     );
   }
   logger('Connected Puppeteer');
+  browserRegistry.set(activeBrowserId, browser);
   return browser;
 }
 
@@ -267,6 +343,7 @@ export async function ensureBrowserLaunched(
     return browser;
   }
   browser = await launch(options);
+  browserRegistry.set(activeBrowserId, browser);
   return browser;
 }
 
diff --git a/src/index.ts b/src/index.ts
index 2689e34a6..dd7447554 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -8,7 +8,7 @@ import type fs from 'node:fs';
 
 import type {parseArguments} from './bin/chrome-devtools-mcp-cli-options.js';
 import type {Channel} from './browser.js';
-import {ensureBrowserConnected, ensureBrowserLaunched} from './browser.js';
+import {ensureBrowserConnected, ensureBrowserLaunched, getActiveBrowserId} from './browser.js';
 import {loadIssueDescriptions} from './issue-descriptions.js';
 import {logger} from './logger.js';
 import {McpContext} from './McpContext.js';
@@ -65,6 +65,7 @@ export async function createMcpServer(
   };
 
   let context: McpContext;
+  const contextRegistry = new Map<string, McpContext>();
   async function getContext(): Promise<McpContext> {
     const chromeArgs: string[] = (serverArgs.chromeArg ?? []).map(String);
     const ignoreDefaultChromeArgs: string[] = (
@@ -103,12 +104,17 @@ export async function createMcpServer(
             viaCli: serverArgs.viaCli,
           });
 
-    if (context?.browser !== browser) {
+    const browserId = getActiveBrowserId();
+    const existingContext = contextRegistry.get(browserId);
+    if (existingContext?.browser === browser && browser?.connected) {
+      context = existingContext;
+    } else if (context?.browser !== browser) {
       context = await McpContext.from(browser, logger, {
         experimentalDevToolsDebugging: devtools,
         experimentalIncludeAllPages: serverArgs.experimentalIncludeAllPages,
         performanceCrux: serverArgs.performanceCrux,
       });
+      contextRegistry.set(browserId, context);
     }
     return context;
   }
diff --git a/src/tools/multibrowser.ts b/src/tools/multibrowser.ts
new file mode 100644
index 000000000..181ed002c
--- /dev/null
+++ b/src/tools/multibrowser.ts
@@ -0,0 +1,116 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import {
+  switchActiveBrowser,
+  listBrowsers,
+  addBrowser,
+} from '../browser.js';
+import {zod} from '../third_party/index.js';
+import {ToolCategory} from './categories.js';
+import {defineTool} from './ToolDefinition.js';
+
+export const switch_browser = defineTool({
+  name: 'switch_browser',
+  description:
+    'Switch the active browser instance. All subsequent tool calls will operate on the selected browser.',
+  annotations: {
+    category: ToolCategory.NAVIGATION,
+    readOnlyHint: false,
+  },
+  schema: {
+    browserId: zod
+      .string()
+      .describe(
+        'The ID of the browser to switch to. Call list_browsers to see available browsers.',
+      ),
+  },
+  handler: async (request, response) => {
+    const {browserId} = request.params;
+    switchActiveBrowser(browserId);
+    response.appendResponseLine(
+      `Switched to browser '${browserId}'. All future tool calls will target this browser.`,
+    );
+    response.appendResponseLine(`Active browser: ${browserId}`);
+  },
+});
+
+export const list_browsers = defineTool({
+  name: 'list_browsers',
+  description:
+    'List all connected browser instances with their IDs and connection status.',
+  annotations: {
+    category: ToolCategory.NAVIGATION,
+    readOnlyHint: true,
+  },
+  schema: {},
+  handler: async (_request, response) => {
+    const browsers = listBrowsers();
+    if (browsers.length === 0) {
+      response.appendResponseLine('No browsers connected.');
+      return;
+    }
+    response.appendResponseLine('## Connected browsers');
+    for (const b of browsers) {
+      const marker = b.active ? ' [selected]' : '';
+      const status = b.connected ? 'connected' : 'disconnected';
+      response.appendResponseLine(`- ${b.id}: ${status}${marker}`);
+    }
+  },
+});
+
+export const add_browser = defineTool({
+  name: 'add_browser',
+  description:
+    'Connect to an additional Chrome browser instance on a different debugging port.',
+  annotations: {
+    category: ToolCategory.NAVIGATION,
+    readOnlyHint: false,
+  },
+  schema: {
+    browserId: zod
+      .string()
+      .describe(
+        'A unique ID for this browser instance (e.g. "admin", "test-user", "dev").',
+      ),
+    browserUrl: zod
+      .string()
+      .describe(
+        'The debugging URL of the Chrome instance (e.g. "http://127.0.0.1:9224").',
+      ),
+    switchTo: zod
+      .boolean()
+      .optional()
+      .describe(
+        'Whether to immediately switch to this browser after connecting. Default is true.',
+      ),
+  },
+  handler: async (request, response) => {
+    const {browserId, browserUrl, switchTo = true} = request.params;
+    try {
+      await addBrowser(browserId, {browserURL: browserUrl});
+      response.appendResponseLine(
+        `Browser '${browserId}' connected successfully at ${browserUrl}.`,
+      );
+      if (switchTo) {
+        switchActiveBrowser(browserId);
+        response.appendResponseLine(`Switched to browser '${browserId}'.`);
+      }
+      const browsers = listBrowsers();
+      response.appendResponseLine('\n## All browsers');
+      for (const b of browsers) {
+        const marker = b.active ? ' [selected]' : '';
+        response.appendResponseLine(
+          `- ${b.id}: ${b.connected ? 'connected' : 'disconnected'}${marker}`,
+        );
+      }
+    } catch (err) {
+      throw new Error(
+        `Failed to connect to browser '${browserId}' at ${browserUrl}: ${(err as Error).message}`,
+      );
+    }
+  },
+});
diff --git a/src/tools/slim/tools.ts b/src/tools/slim/tools.ts
index 712dcff63..039b3f52f 100644
--- a/src/tools/slim/tools.ts
+++ b/src/tools/slim/tools.ts
@@ -9,6 +9,8 @@ import {zod} from '../../third_party/index.js';
 import {ToolCategory} from '../categories.js';
 import {definePageTool} from '../ToolDefinition.js';
 
+export {switch_browser, list_browsers, add_browser} from '../multibrowser.js';
+
 export const screenshot = definePageTool({
   name: 'screenshot',
   description: `Takes a screenshot`,
diff --git a/src/tools/tools.ts b/src/tools/tools.ts
index d448552b0..2a24e3a7b 100644
--- a/src/tools/tools.ts
+++ b/src/tools/tools.ts
@@ -20,6 +20,7 @@ import * as screenshotTools from './screenshot.js';
 import * as scriptTools from './script.js';
 import * as slimTools from './slim/tools.js';
 import * as snapshotTools from './snapshot.js';
+import * as multibrowserTools from './multibrowser.js';
 import type {ToolDefinition} from './ToolDefinition.js';
 
 export const createTools = (args: ParsedArguments) => {
@@ -39,6 +40,7 @@ export const createTools = (args: ParsedArguments) => {
         ...Object.values(screenshotTools),
         ...Object.values(scriptTools),
         ...Object.values(snapshotTools),
+        ...Object.values(multibrowserTools),
       ];
 
   const tools = [];