diff --git a/src/components/modal/Config.tsx b/src/components/modal/Config.tsx
index 0959fe5..9161ae2 100644
--- a/src/components/modal/Config.tsx
+++ b/src/components/modal/Config.tsx
@@ -16,6 +16,7 @@ import LazyLoad from '@/components/utils/LazyLoad';
 import usePopup from '@/components/utils/usePopup';
 import { colorThemes } from '@/core/colorThemes';
 import useConfig, { type Config } from '@/core/useConfig';
+import { useOldConfig } from '@/hooks/useInterWindow';
 import useModalState from '@/hooks/useModalState';
 import { useTranslation } from '@/i18n/useTranslation';
 import usePubkey from '@/nostr/usePubkey';
@@ -634,6 +635,7 @@ const OtherConfig = () => {
 const ConfigUI = (props: ConfigProps) => {
   const i18n = useTranslation();
   const [menuIndex, setMenuIndex] = createSignal<number | null>(null);
+  const { canImport, importConfig } = useOldConfig();
 
   const menu = [
     {
@@ -690,6 +692,19 @@ const ConfigUI = (props: ConfigProps) => {
           fallback={
             <>
               <h2 class="flex-1 text-center text-lg font-bold">{i18n()('config.config')}</h2>
+              <Show when={canImport()}>
+                <button
+                  type="button"
+                  class="rounded bg-primary p-2 text-primary-fg"
+                  onClick={() => {
+                    if (window.confirm(i18n()('config.confirmImportOldDomainConfig'))) {
+                      importConfig();
+                    }
+                  }}
+                >
+                  {i18n()('config.importOldDomainConfig')}
+                </button>
+              </Show>
               <ul class="flex flex-col">
                 <For each={menu}>
                   {(menuItem, i) => (
diff --git a/src/hooks/useInterWindow.tsx b/src/hooks/useInterWindow.tsx
new file mode 100644
index 0000000..921a3bd
--- /dev/null
+++ b/src/hooks/useInterWindow.tsx
@@ -0,0 +1,123 @@
+import { createSignal, onMount, onCleanup, observable } from 'solid-js';
+
+import useConfig from '@/core/useConfig';
+import {
+  type InterWindowRequest,
+  type InterWindowRequestWithId,
+  type InterWindowResponseWithId,
+} from '@/interWindow';
+
+const useInterWindow = (url: string) => {
+  let iframeRef: HTMLIFrameElement | undefined;
+  const [loaded, setLoaded] = createSignal(false);
+
+  onMount(() => {
+    iframeRef = (<iframe title="interwindow" class="hidden" src={url} />) as HTMLIFrameElement;
+    document.body.appendChild(iframeRef);
+    iframeRef.addEventListener('load', () => setLoaded(true));
+    onCleanup(() => {
+      iframeRef?.remove();
+    });
+  });
+
+  const waitLoaded = (): Promise<void> => {
+    if (loaded()) return Promise.resolve();
+    return new Promise((resolve) => {
+      observable(loaded).subscribe((v) => {
+        if (v) resolve();
+      });
+    });
+  };
+
+  const listen = async (
+    expectedRequestId: number,
+    timeout: number = 2000,
+  ): Promise<InterWindowResponseWithId> =>
+    new Promise((resolve, reject) => {
+      const listener = (event: MessageEvent) => {
+        console.log('message received', event);
+        if (event.origin !== new URL(url).origin) return;
+        if (typeof event.data !== 'string') return;
+
+        const data = JSON.parse(event.data) as InterWindowResponseWithId;
+
+        if (data.requestId !== expectedRequestId) return;
+
+        window.removeEventListener('message', listener);
+        resolve(data);
+      };
+
+      setTimeout(() => {
+        reject(new Error('timeout'));
+        window.removeEventListener('message', listener);
+      }, timeout);
+
+      window.addEventListener('message', listener, false);
+    });
+
+  const request = async (message: InterWindowRequest) => {
+    const requestId = Math.random();
+    const withId = { ...message, requestId } satisfies InterWindowRequestWithId;
+    const messageStr = JSON.stringify(withId);
+
+    await waitLoaded();
+    const promise = listen(requestId);
+    if (iframeRef == null) {
+      throw new Error('iframeRef is null');
+    }
+    if (!loaded()) {
+      throw new Error('iframeRef is not loaded');
+    }
+    iframeRef.contentWindow?.postMessage(messageStr, new URL(url).origin);
+    return promise;
+  };
+
+  const getConfig = () => request({ type: 'GET_CONFIG' });
+
+  return {
+    loaded,
+    request,
+    getConfig,
+  };
+};
+
+export const useOldConfig = () => {
+  const url = 'https://syusui-s.github.io/rabbit/transfer-config.html';
+  const { getConfig } = useInterWindow(url);
+  const { setConfig } = useConfig();
+
+  const [oldConfig, setOldConfig] = createSignal<string | undefined>();
+
+  const canImport = () => {
+    const c = oldConfig();
+    return c != null && c.length > 0;
+  };
+
+  const importConfig = () => {
+    const c = oldConfig();
+    if (c != null && c.length > 0) {
+      setConfig(JSON.parse(c));
+    }
+  };
+
+  onMount(() => {
+    setTimeout(() => {
+      getConfig()
+        .then((obtainedConfig) => {
+          if (typeof obtainedConfig.payload === 'string' && obtainedConfig.payload.length > 0) {
+            setOldConfig(obtainedConfig.payload);
+          }
+        })
+        .catch((err) => {
+          console.error(err);
+        });
+    }, 100);
+  });
+
+  return {
+    canImport,
+    importConfig,
+  };
+};
+
+export default useInterWindow;
diff --git a/src/interWindow.ts b/src/interWindow.ts
new file mode 100644
index 0000000..e010dba
--- /dev/null
+++ b/src/interWindow.ts
@@ -0,0 +1,38 @@
+export type InterWindowRequest = {
+  type: 'GET_CONFIG';
+};
+
+export type InterWindowRequestWithId = InterWindowRequest & {
+  requestId: number;
+};
+
+export type InterWindowResponse = {
+  type: 'OK' | 'BAD_REQUEST' | 'NOT_FOUND' | 'INTERNAL_PEER_ERROR';
+  payload?: string;
+};
+
+export type InterWindowResponseWithId = InterWindowResponse & {
+  requestId: number;
+};
+
+export type RequestHandler = (request: InterWindowRequestWithId) => InterWindowResponse;
+
+export const ok = (payload?: string): InterWindowResponse => ({
+  type: 'OK',
+  payload,
+});
+
+export const badRequest = (payload?: string): InterWindowResponse => ({
+  type: 'BAD_REQUEST',
+  payload,
+});
+
+export const notFound = (payload?: string): InterWindowResponse => ({
+  type: 'NOT_FOUND',
+  payload,
+});
+
+export const internalPeerError = (payload?: string): InterWindowResponse => ({
+  type: 'INTERNAL_PEER_ERROR',
+  payload,
+});
diff --git a/src/locales/en.ts b/src/locales/en.ts
index b6b3417..3b880cc 100644
--- a/src/locales/en.ts
+++ b/src/locales/en.ts
@@ -125,6 +125,8 @@ export default {
   },
   config: {
     config: 'Settings',
+    importOldDomainConfig: 'Import config from the old domain',
+    confirmImportOldDomainConfig: 'Import? (The config will be overwritten)',
     profile: {
       profile: 'Profile',
       openProfile: 'Open',
diff --git a/src/locales/ja.ts b/src/locales/ja.ts
index dcf2775..e2c4651 100644
--- a/src/locales/ja.ts
+++ b/src/locales/ja.ts
@@ -121,6 +121,8 @@ export default {
   },
   config: {
     config: '設定',
+    importOldDomainConfig: '古いドメインから設定をインポート',
+    confirmImportOldDomainConfig: 'インポートしますか？（現在の設定は上書きされます）',
     profile: {
       profile: 'プロフィール',
       openProfile: '開く',
diff --git a/src/pages/Hello.tsx b/src/pages/Hello.tsx
index 1fd1b65..7b81671 100644
--- a/src/pages/Hello.tsx
+++ b/src/pages/Hello.tsx
@@ -2,6 +2,8 @@ import { createSignal, onMount, Switch, Match, type Component } from 'solid-js';
 
 import { useNavigate } from '@solidjs/router';
 
+import useConfig from '@/core/useConfig';
+import { useOldConfig } from '@/hooks/useInterWindow';
 import usePersistStatus from '@/hooks/usePersistStatus';
 import { useTranslation } from '@/i18n/useTranslation';
 import resolveAsset from '@/utils/resolveAsset';
@@ -36,13 +38,24 @@ const Hello: Component = () => {
   const signerStatus = useSignerStatus();
   const navigate = useNavigate();
   const { persistStatus, loggedIn } = usePersistStatus();
+  const { config } = useConfig();
+  const { canImport, importConfig } = useOldConfig();
 
   const handleLogin = () => {
+    if (
+      config().columns.length === 0 &&
+      canImport() &&
+      window.confirm('import config from old domain?')
+    ) {
+      importConfig();
+    }
+
     loggedIn();
     navigate('/');
   };
 
   onMount(() => {
+    console.log();
     if (persistStatus().loggedIn) {
       navigate('/');
     }
diff --git a/transfer-config.html b/transfer-config.html
new file mode 100644
index 0000000..b5fde3e
--- /dev/null
+++ b/transfer-config.html
@@ -0,0 +1,9 @@
+<!doctype html>
+<html>
+  <head>
+    <meta charset="utf-8" />
+    <title>Transfer Config</title>
+    <script src="transfer-config.ts" type="module"></script>
+  </head>
+  <body></body>
+</html>
diff --git a/transfer-config.ts b/transfer-config.ts
new file mode 100644
index 0000000..a89cecf
--- /dev/null
+++ b/transfer-config.ts
@@ -0,0 +1,53 @@
+import {
+  ok,
+  notFound,
+  internalPeerError,
+  type InterWindowRequestWithId,
+  type RequestHandler,
+} from '@/interWindow';
+
+(() => {
+  const acceptableOrigins = [
+    window.location.origin,
+    'http://localhost:3000',
+    'http://localhost:12345',
+    'https://rabbit.syusui.net',
+  ];
+
+  const rawMessageHandler = (handler: RequestHandler) => (event: MessageEvent) => {
+    console.log('transfer-config: received request', event.data, event.origin);
+    if (!acceptableOrigins.includes(event.origin)) return;
+
+    const { origin, source } = event;
+    if (typeof event.data !== 'string') return;
+    const request = JSON.parse(event.data) as InterWindowRequestWithId;
+
+    let responseObj;
+    try {
+      responseObj = handler(request);
+    } catch (e) {
+      responseObj = internalPeerError(undefined);
+    }
+
+    const response = JSON.stringify({ requestId: request.requestId, ...responseObj });
+    // @ts-expect-error postMessage
+    source?.postMessage(response, origin);
+  };
+
+  window.addEventListener(
+    'message',
+    rawMessageHandler((request) => {
+      switch (request.type) {
+        case 'GET_CONFIG': {
+          const value = window.localStorage.getItem('RabbitConfig') ?? '';
+          return ok(value);
+        }
+        default:
+          return notFound();
+      }
+    }),
+    false,
+  );
+
+  console.log('transfer-config: mounted');
+})();
diff --git a/vite.config.ts b/vite.config.ts
index 4ae4876..bd8175b 100644
--- a/vite.config.ts
+++ b/vite.config.ts
@@ -14,6 +14,12 @@ export default defineConfig({
   build: {
     target: 'esnext',
     sourcemap: true,
+    rollupOptions: {
+      input: {
+        main: './index.html',
+        transferConfig: './transfer-config.html',
+      },
+    },
   },
   resolve: {
     alias: {