diff --git a/packages/backend/src/server/web/ClientServerService.ts b/packages/backend/src/server/web/ClientServerService.ts
index 3cd83efa1a..25bbf14b4a 100644
--- a/packages/backend/src/server/web/ClientServerService.ts
+++ b/packages/backend/src/server/web/ClientServerService.ts
@@ -158,13 +158,19 @@ export class ClientServerService {
 				'purpose': 'any',
 			}],
 			'share_target': {
-				'action': '/share/',
-				'method': 'GET',
-				'enctype': 'application/x-www-form-urlencoded',
+				'action': '/sw/share',
+				'method': 'POST',
+				'enctype': 'multipart/form-data',
 				'params': {
 					'title': 'title',
 					'text': 'text',
 					'url': 'url',
+					'files': [
+						{
+							'name': 'files',
+							'accept': '*/*',
+						},
+					],
 				},
 			},
 			'shortcuts': [{
diff --git a/packages/backend/src/server/web/manifest.json b/packages/backend/src/server/web/manifest.json
index 90d4530857..5c06fe61a8 100644
--- a/packages/backend/src/server/web/manifest.json
+++ b/packages/backend/src/server/web/manifest.json
@@ -26,13 +26,19 @@
 		}
 	],
 	"share_target": {
-		"action": "/share/",
-		"method": "GET",
-		"enctype": "application/x-www-form-urlencoded",
+		"action": "/sw/share",
+		"method": "POST",
+		"enctype": "multipart/form-data",
 		"params": {
 			"title": "title",
 			"text": "text",
-			"url": "url"
+			"url": "url",
+			"files": [
+				{
+					"name": "files",
+					"accept": "*/*"
+				}
+			]
 		}
 	},
 	"shortcuts": [
diff --git a/packages/frontend/src/components/MkPostForm.vue b/packages/frontend/src/components/MkPostForm.vue
index 17f93a4ec8..429fc605ad 100644
--- a/packages/frontend/src/components/MkPostForm.vue
+++ b/packages/frontend/src/components/MkPostForm.vue
@@ -227,6 +227,10 @@ uploader.events.on('itemUploaded', ctx => {
 	uploader.removeItem(ctx.item);
 });
 
+if (props.initialLocalFiles) {
+	uploader.addFiles(props.initialLocalFiles);
+}
+
 const draftKey = computed((): string => {
 	let key = targetChannel.value ? `channel:${targetChannel.value.id}` : '';
 
diff --git a/packages/frontend/src/pages/share.vue b/packages/frontend/src/pages/share.vue
index 368537ec91..9c24e0a3ec 100644
--- a/packages/frontend/src/pages/share.vue
+++ b/packages/frontend/src/pages/share.vue
@@ -13,6 +13,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 			:initialText="initialText"
 			:initialVisibility="visibility"
 			:initialFiles="files"
+			:initialLocalFiles="tempFiles"
 			:initialLocalOnly="localOnly"
 			:reply="reply"
 			:renote="renote"
@@ -33,6 +34,7 @@ SPDX-License-Identifier: AGPL-3.0-only
 
 import { ref, computed } from 'vue';
 import * as Misskey from 'misskey-js';
+import { get, del } from 'idb-keyval';
 import MkButton from '@/components/MkButton.vue';
 import MkPostForm from '@/components/MkPostForm.vue';
 import * as os from '@/os.js';
@@ -41,7 +43,19 @@ import { definePage } from '@/page.js';
 import { postMessageToParentWindow } from '@/utility/post-message.js';
 import { i18n } from '@/i18n.js';
 
+//#region parameters
 const urlParams = new URLSearchParams(window.location.search);
+// merge hash parameters
+try {
+	const hashParams = new URLSearchParams(window.location.hash.slice(1));
+	for (const [key, value] of hashParams.entries()) {
+		urlParams.set(key, value);
+	}
+} catch (e) {
+	console.error('Failed to parse hash parameters:', e);
+}
+//#endregion
+
 const localOnlyQuery = urlParams.get('localOnly');
 const visibilityQuery = urlParams.get('visibility') as typeof Misskey.noteVisibilities[number];
 
@@ -56,6 +70,7 @@ const visibility = ref(Misskey.noteVisibilities.includes(visibilityQuery) ? visi
 const localOnly = ref(localOnlyQuery === '0' ? false : localOnlyQuery === '1' ? true : undefined);
 const files = ref([] as Misskey.entities.DriveFile[]);
 const visibleUsers = ref([] as Misskey.entities.UserDetailed[]);
+const tempFiles = ref([] as File[]);
 
 async function init() {
 	let noteText = '';
@@ -181,6 +196,29 @@ async function init() {
 		});
 	}
 
+	//#region Local files
+	// If the browser supports IndexedDB, try to get the temporary files from temp.
+	if (typeof window !== 'undefined' ? !!(window.indexedDB && typeof window.indexedDB.open === 'function') : true) {
+		const filesFromIdb = await get<File[]>('share-files-temp');
+		if (Array.isArray(filesFromIdb) && filesFromIdb.length > 0 && filesFromIdb.every(file => file instanceof Blob)) {
+			tempFiles.value = filesFromIdb;
+		}
+	}
+
+	if (urlParams.has('file') && urlParams.get('file').startsWith('data:')) {
+		try {
+			const file = await window.fetch(urlParams.get('file')).then(res => res.blob());
+			if (file instanceof Blob) {
+				tempFiles.value.push(file as File);
+			} else {
+				console.error('Fetched file is not a Blob:', file);
+			}
+		} catch (e) {
+			console.error('Failed to fetch file:', e);
+		}
+	}
+	//#endregion
+
 	state.value = 'writing';
 }
 
@@ -201,10 +239,31 @@ function goToMisskey(): void {
 
 function onPosted(): void {
 	state.value = 'posted';
+	// SWが保存したファイルは投稿が完了するまでIndexedDBに保持
+	del('share-files-temp');
 	postMessageToParentWindow('misskey:shareForm:shareCompleted');
 }
 
-const headerActions = computed(() => []);
+const headerActions = computed(() => [
+	{
+		icon: 'ti ti-dots',
+		text: i18n.ts.menu,
+		handler: (ev: MouseEvent) => {
+			os.popupMenu([
+				{
+					icon: 'ti ti-home',
+					text: i18n.ts.goToMisskey,
+					action: () => goToMisskey(),
+				},
+				{
+					icon: 'ti ti-x',
+					text: i18n.ts.close,
+					action: () => close(),
+				},
+			], ev.currentTarget ?? ev.target);
+		},
+	},
+]);
 
 const headerTabs = computed(() => []);
 
diff --git a/packages/frontend/src/types/post-form.ts b/packages/frontend/src/types/post-form.ts
index 90c8605f31..00d274656b 100644
--- a/packages/frontend/src/types/post-form.ts
+++ b/packages/frontend/src/types/post-form.ts
@@ -22,6 +22,7 @@ export interface PostFormProps {
 	initialCw?: string;
 	initialVisibility?: (typeof Misskey.noteVisibilities)[number];
 	initialFiles?: Misskey.entities.DriveFile[];
+	initialLocalFiles?: File[];
 	initialLocalOnly?: boolean;
 	initialVisibleUsers?: Misskey.entities.UserDetailed[];
 	initialNote?: Misskey.entities.Note;
diff --git a/packages/sw/src/sw.ts b/packages/sw/src/sw.ts
index 298af4b4b6..933437f8cf 100644
--- a/packages/sw/src/sw.ts
+++ b/packages/sw/src/sw.ts
@@ -3,7 +3,7 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
-import { get } from 'idb-keyval';
+import { get, set } from 'idb-keyval';
 import * as Misskey from 'misskey-js';
 import type { PushNotificationDataMap } from '@/types.js';
 import type { I18n } from '@@/js/i18n.js';
@@ -40,6 +40,34 @@ async function offlineContentHTML() {
 }
 
 globalThis.addEventListener('fetch', ev => {
+	//#region /sw/share
+	const url = new URL(ev.request.url);
+	if (url.pathname === '/sw/share') {
+		ev.respondWith((async () => {
+			const responseUrl = new URL(ev.request.url);
+			responseUrl.pathname = '/share';
+			const formData = await ev.request.formData();
+
+			// とりあえず初期化 (IndexedDBの削除は時間がかかる可能性があるため空の配列をセット)
+			await set('share-url-temp', []);
+			if (formData.has('files')) {
+				const files = formData.getAll('files');
+				if (files.length > 0 && files.every(file => file instanceof Blob)) {
+					set('share-files-temp', files);
+				}
+			}
+
+			formData.delete('files');
+			for (const [key, value] of formData.entries()) {
+				responseUrl.searchParams.set(key, value.toString());
+			}
+
+			return Response.redirect(responseUrl, 303);
+		})());
+		return;
+	}
+
+	//#region others
 	let isHTMLRequest = false;
 	if (ev.request.headers.get('sec-fetch-dest') === 'document') {
 		isHTMLRequest = true;
@@ -62,6 +90,7 @@ globalThis.addEventListener('fetch', ev => {
 				});
 			}),
 	);
+	//#endregion
 });
 
 globalThis.addEventListener('push', ev => {