diff --git a/chrome/content/zotero/xpcom/pdfWorker/manager.js b/chrome/content/zotero/xpcom/pdfWorker/manager.js
index e2a8a060bd..9e230895be 100644
--- a/chrome/content/zotero/xpcom/pdfWorker/manager.js
+++ b/chrome/content/zotero/xpcom/pdfWorker/manager.js
@@ -410,6 +410,162 @@ class PDFWorker {
 		}
 		await Promise.all(promises);
 	}
+
+	/**
+	 * Delete pages from PDF attachment
+	 *
+	 * @param {Integer} itemID Attachment item id
+	 * @param {Array} pageIndexes
+	 * @param {Boolean} [isPriority]
+	 * @param {String} [password]
+	 * @returns {Promise}
+	 */
+	async deletePages(itemID, pageIndexes, isPriority, password) {
+		return this._enqueue(async () => {
+			let attachment = await Zotero.Items.getAsync(itemID);
+
+			Zotero.debug(`Deleting [${pageIndexes.join(', ')}] pages for item ${attachment.libraryKey}`);
+			let t = new Date();
+
+			if (!attachment.isPDFAttachment()) {
+				throw new Error('Item must be a PDF attachment');
+			}
+
+			let annotations = attachment
+				.getAnnotations()
+				.map(annotation => ({
+					id: annotation.id,
+					position: JSON.parse(annotation.annotationPosition)
+				}));
+
+			let path = await attachment.getFilePathAsync();
+			let buf = await OS.File.read(path, {});
+			buf = new Uint8Array(buf).buffer;
+
+			try {
+				var { buf: modifiedBuf } = await this._query('deletePages', {
+					buf, pageIndexes, password
+				}, [buf]);
+			}
+			catch (e) {
+				let error = new Error(`Worker 'deletePages' failed: ${JSON.stringify({ error: e.message })}`);
+				try {
+					error.name = JSON.parse(e.message).name;
+				}
+				catch (e) {
+					Zotero.logError(e);
+				}
+				Zotero.logError(error);
+				throw error;
+			}
+
+			// Delete annotations from deleted pages
+			let ids = [];
+			for (let i = annotations.length - 1; i >= 0; i--) {
+				let { id, position } = annotations[i];
+				if (pageIndexes.includes(position.pageIndex)) {
+					ids.push(id);
+					annotations.splice(i, 1);
+				}
+			}
+			if (ids.length) {
+				await Zotero.Items.erase(ids);
+			}
+
+			// Shift page index for other annotations
+			ids = [];
+			await Zotero.DB.executeTransaction(async function () {
+				let rows = await Zotero.DB.queryAsync('SELECT itemID, position FROM itemAnnotations WHERE parentItemID=?', itemID);
+				for (let { itemID, position } of rows) {
+					try {
+						position = JSON.parse(position);
+					}
+					catch (e) {
+						Zotero.logError(e);
+						continue;
+					}
+					// Find the count of deleted pages before the current annotation page
+					let shift = pageIndexes.reduce((prev, cur) => cur < position.pageIndex ? prev + 1 : prev, 0);
+					if (shift > 0) {
+						position.pageIndex -= shift;
+						position = JSON.stringify(position);
+						await Zotero.DB.queryAsync('UPDATE itemAnnotations SET position=? WHERE itemID=?', [position, itemID]);
+						ids.push(itemID);
+					}
+				}
+			});
+			let objectsClass = Zotero.DataObjectUtilities.getObjectsClassForObjectType('item');
+			let loadedObjects = objectsClass.getLoaded();
+			for (let object of loadedObjects) {
+				if (ids.includes(object.id)) {
+					await object.reload(null, true);
+				}
+			}
+			await Zotero.Notifier.trigger('modify', 'item', ids, {});
+
+			await OS.File.writeAtomic(path, new Uint8Array(modifiedBuf));
+			let mtime = Math.floor(await attachment.attachmentModificationTime / 1000);
+			attachment.attachmentLastProcessedModificationTime = mtime;
+			await attachment.saveTx({
+				skipAll: true
+			});
+
+			Zotero.debug(`Deleted pages for item ${attachment.libraryKey} in ${new Date() - t} ms`);
+		}, isPriority);
+	}
+
+	/**
+	 * Rotate pages in PDF attachment
+	 *
+	 * @param {Integer} itemID Attachment item id
+	 * @param {Array} pageIndexes
+	 * @param {Integer} degrees 90, 180, 270
+	 * @param {Boolean} [isPriority]
+	 * @param {String} [password]
+	 * @returns {Promise}
+	 */
+	async rotatePages(itemID, pageIndexes, degrees, isPriority, password) {
+		return this._enqueue(async () => {
+			let attachment = await Zotero.Items.getAsync(itemID);
+
+			Zotero.debug(`Rotating [${pageIndexes.join(', ')}] pages for item ${attachment.libraryKey}`);
+			let t = new Date();
+
+			if (!attachment.isPDFAttachment()) {
+				throw new Error('Item must be a PDF attachment');
+			}
+
+			let path = await attachment.getFilePathAsync();
+			let buf = await OS.File.read(path, {});
+			buf = new Uint8Array(buf).buffer;
+
+			try {
+				var { buf: modifiedBuf } = await this._query('rotatePages', {
+					buf, pageIndexes, degrees, password
+				}, [buf]);
+			}
+			catch (e) {
+				let error = new Error(`Worker 'rotatePages' failed: ${JSON.stringify({ error: e.message })}`);
+				try {
+					error.name = JSON.parse(e.message).name;
+				}
+				catch (e) {
+					Zotero.logError(e);
+				}
+				Zotero.logError(error);
+				throw error;
+			}
+
+			await OS.File.writeAtomic(path, new Uint8Array(modifiedBuf));
+			let mtime = Math.floor(await attachment.attachmentModificationTime / 1000);
+			attachment.attachmentLastProcessedModificationTime = mtime;
+			await attachment.saveTx({
+				skipAll: true
+			});
+
+			Zotero.debug(`Rotated pages for item ${attachment.libraryKey} in ${new Date() - t} ms`);
+		}, isPriority);
+	}
 }
 
 Zotero.PDFWorker = new PDFWorker();
diff --git a/chrome/content/zotero/xpcom/reader.js b/chrome/content/zotero/xpcom/reader.js
index aed2e14829..d20c8d07ca 100644
--- a/chrome/content/zotero/xpcom/reader.js
+++ b/chrome/content/zotero/xpcom/reader.js
@@ -249,6 +249,33 @@ class ReaderInstance {
 		);
 		return !index;
 	}
+
+	promptToDeletePages(num) {
+		let ps = Services.prompt;
+		let buttonFlags = ps.BUTTON_POS_0 * ps.BUTTON_TITLE_IS_STRING
+			+ ps.BUTTON_POS_1 * ps.BUTTON_TITLE_CANCEL;
+		let index = ps.confirmEx(
+			null,
+			Zotero.getString('pdfReader.promptDeletePages.title'),
+			Zotero.getString(
+				'pdfReader.promptDeletePages.text',
+				new Intl.NumberFormat().format(num),
+				num
+			),
+			buttonFlags,
+			Zotero.getString('general.continue'),
+			null, null, null, {}
+		);
+		return !index;
+	}
+
+	async reload() {
+		let item = Zotero.Items.get(this._itemID);
+		let path = await item.getFilePathAsync();
+		let buf = await OS.File.read(path, {});
+		buf = new Uint8Array(buf).buffer;
+		this._postMessage({ action: 'reload', buf, }, [buf]);
+	}
 	
 	async menuCmd(cmd) {
 		if (cmd === 'transferFromPDF') {
@@ -668,6 +695,60 @@ class ReaderInstance {
 		popup.openPopup(element, 'after_start', 0, 0, true);
 	}
 
+	_openThumbnailPopup(data) {
+		let popup = this._window.document.createElement('menupopup');
+		this._popupset.appendChild(popup);
+		popup.addEventListener('popuphidden', function () {
+			popup.remove();
+		});
+		let menuitem;
+		// Rotate 90
+		menuitem = this._window.document.createElement('menuitem');
+		menuitem.setAttribute('label', Zotero.getString('pdfReader.rotate90'));
+		menuitem.addEventListener('command', async () => {
+			this._postMessage({ action: 'reloading' });
+			await Zotero.PDFWorker.rotatePages(this._itemID, data.pageIndexes, 90, true);
+			await this.reload();
+		});
+		popup.appendChild(menuitem);
+		// Rotate 180
+		menuitem = this._window.document.createElement('menuitem');
+		menuitem.setAttribute('label', Zotero.getString('pdfReader.rotate180'));
+		menuitem.addEventListener('command', async () => {
+			this._postMessage({ action: 'reloading' });
+			await Zotero.PDFWorker.rotatePages(this._itemID, data.pageIndexes, 180, true);
+			await this.reload();
+		});
+		popup.appendChild(menuitem);
+		// Rotate 270
+		menuitem = this._window.document.createElement('menuitem');
+		menuitem.setAttribute('label', Zotero.getString('pdfReader.rotate270'));
+		menuitem.addEventListener('command', async () => {
+			this._postMessage({ action: 'reloading' });
+			await Zotero.PDFWorker.rotatePages(this._itemID, data.pageIndexes, 270, true);
+			await this.reload();
+		});
+		popup.appendChild(menuitem);
+		// Separator
+		popup.appendChild(this._window.document.createElement('menuseparator'));
+		// Delete
+		menuitem = this._window.document.createElement('menuitem');
+		menuitem.setAttribute('label', Zotero.getString('general.delete'));
+		menuitem.addEventListener('command', async () => {
+			if (this.promptToDeletePages(data.pageIndexes.length)) {
+				this._postMessage({ action: 'reloading' });
+				try {
+					await Zotero.PDFWorker.deletePages(this._itemID, data.pageIndexes, true);
+				}
+				catch (e) {
+				}
+				await this.reload();
+			}
+		});
+		popup.appendChild(menuitem);
+		popup.openPopupAtScreen(data.x, data.y, true);
+	}
+
 	_openSelectorPopup(data) {
 		let popup = this._window.document.createXULElement('menupopup');
 		this._popupset.appendChild(popup);
@@ -806,6 +887,10 @@ class ReaderInstance {
 					this._openColorPopup(message.data);
 					return;
 				}
+				case 'openThumbnailPopup': {
+					this._openThumbnailPopup(message.data);
+					return;
+				}
 				case 'closePopup': {
 					// Note: This currently only closes tags popup when annotations are
 					// disappearing from pdf-reader sidebar
diff --git a/chrome/locale/en-US/zotero/zotero.properties b/chrome/locale/en-US/zotero/zotero.properties
index 0efd483365..ba91df0a19 100644
--- a/chrome/locale/en-US/zotero/zotero.properties
+++ b/chrome/locale/en-US/zotero/zotero.properties
@@ -1379,6 +1379,11 @@ pdfReader.promptTransferFromPDF.text = Annotations stored in the PDF file will b
 pdfReader.promptTransferToPDF.title = Store Annotations in File
 pdfReader.promptTransferToPDF.text = Annotations will be transferred to the PDF file and will no longer be editable in %S.
 pdfReader.promptPasswordProtected = The operation is not supported for password-protected PDF files.
+pdfReader.promptDeletePages.title = Delete Pages
+pdfReader.promptDeletePages.text = Are you sure you want to delete %1$S page from the PDF file?;Are you sure you want to delete %1$S pages from the PDF file?
+pdfReader.rotate90 = Rotate 90°
+pdfReader.rotate180 = Rotate 180°
+pdfReader.rotate270 = Rotate 270°
 pdfReader.editPageNumber = Edit Page Number…
 pdfReader.editHighlightedText = Edit Highlighted Text
 pdfReader.pageNumberPopupHeader = Change page number for:
diff --git a/pdf-reader b/pdf-reader
index 4d7ce02e92..ac7cae37ae 160000
--- a/pdf-reader
+++ b/pdf-reader
@@ -1 +1 @@
-Subproject commit 4d7ce02e92de6a888ee35bd837e056a76a270cdb
+Subproject commit ac7cae37ae8ba5ea8fc5e0b2a3faebd2d432e65a
diff --git a/pdf-worker b/pdf-worker
index 03e80435d3..eca1523779 160000
--- a/pdf-worker
+++ b/pdf-worker
@@ -1 +1 @@
-Subproject commit 03e80435d3390d8a61a67244dc0279bc6b64f134
+Subproject commit eca15237791a0d16c407dc397e0e53459e951464