diff --git a/src/calibre/gui2/viewer/ui.py b/src/calibre/gui2/viewer/ui.py
index 0a59c11bf4..a0a850ba0f 100644
--- a/src/calibre/gui2/viewer/ui.py
+++ b/src/calibre/gui2/viewer/ui.py
@@ -48,6 +48,8 @@ class EbookViewer(MainWindow):
 
     def __init__(self):
         MainWindow.__init__(self, None)
+        self.base_window_title = _('E-book viewer')
+        self.setWindowTitle(self.base_window_title)
         self.in_full_screen_mode = None
         try:
             os.makedirs(annotations_dir)
@@ -161,6 +163,7 @@ class EbookViewer(MainWindow):
 
     def load_ebook(self, pathtoebook, open_at=None, reload_book=False):
         # TODO: Implement open_at
+        self.setWindowTitle(_('Loading book … — {}').format(self.base_window_title))
         self.web_view.show_preparing_message()
         self.save_annotations()
         self.current_book_data = {}
@@ -185,6 +188,7 @@ class EbookViewer(MainWindow):
 
     def load_finished(self, ok, data):
         if not ok:
+            self.setWindowTitle(self.base_window_title)
             error_dialog(self, _('Loading book failed'), _(
                 'Failed to open the book at {0}. Click "Show details" for more info.').format(data['pathtoebook']),
                 det_msg=data['tb'], show=True)
@@ -194,6 +198,7 @@ class EbookViewer(MainWindow):
         self.current_book_data['annotations_map'] = defaultdict(list)
         self.current_book_data['annotations_path_key'] = path_key(data['pathtoebook']) + '.json'
         self.load_book_data()
+        self.update_window_title()
         self.web_view.start_book_load(initial_cfi=self.initial_cfi_for_current_book())
 
     def load_book_data(self):
@@ -206,6 +211,8 @@ class EbookViewer(MainWindow):
         self.toc_model = TOC(toc)
         self.toc.setModel(self.toc_model)
         self.bookmarks_widget.set_bookmarks(self.current_book_data['annotations_map']['bookmark'])
+        self.current_book_data['metadata'] = set_book_path.parsed_metadata
+        self.current_book_data['manifest'] = set_book_path.parsed_manifest
 
     def load_book_annotations(self):
         amap = self.current_book_data['annotations_map']
@@ -219,6 +226,12 @@ class EbookViewer(MainWindow):
             with open(path, 'rb') as f:
                 raw = f.read()
             merge_annotations(parse_annotations(raw), amap)
+
+    def update_window_title(self):
+        title = self.current_book_data['metadata']['title']
+        book_format = self.current_book_data['manifest']['book_format']
+        title = '{} [{}] — {}'.format(title, book_format, self.base_window_title)
+        self.setWindowTitle(title)
     # }}}
 
     # CFI management {{{
diff --git a/src/calibre/gui2/viewer/web_view.py b/src/calibre/gui2/viewer/web_view.py
index 63984cf453..565221162f 100644
--- a/src/calibre/gui2/viewer/web_view.py
+++ b/src/calibre/gui2/viewer/web_view.py
@@ -29,6 +29,7 @@ from calibre.gui2.webengine import (
 )
 from calibre.srv.code import get_translations_data
 from calibre.utils.config import JSONConfig
+from calibre.utils.serialize import json_loads
 from polyglot.builtins import iteritems
 
 try:
@@ -44,9 +45,14 @@ vprefs.defaults['main_window_geometry'] = None
 
 # Override network access to load data from the book {{{
 
-
 def set_book_path(path=None):
-    set_book_path.path = os.path.abspath(path)
+    if path is not None:
+        set_book_path.path = os.path.abspath(path)
+        set_book_path.metadata = get_data('calibre-book-metadata.json')[0]
+        set_book_path.manifest, set_book_path.manifest_mime = get_data('calibre-book-manifest.json')
+        set_book_path.metadata = get_data('calibre-book-metadata.json')[0]
+        set_book_path.parsed_metadata = json_loads(set_book_path.metadata)
+        set_book_path.parsed_manifest = json_loads(set_book_path.manifest)
 
 
 def get_data(name):
@@ -116,10 +122,8 @@ class UrlSchemeHandler(QWebEngineUrlSchemeHandler):
                 traceback.print_exc()
                 rq.fail(rq.RequestFailed)
         elif name == 'manifest':
-            manifest, mime_type = get_data('calibre-book-manifest.json')
-            metadata = get_data('calibre-book-metadata.json')[0]
-            data = b'[' + manifest + b',' + metadata + b']'
-            send_reply(rq, mime_type, data)
+            data = b'[' + set_book_path.manifest + b',' + set_book_path.metadata + b']'
+            send_reply(rq, set_book_path.manifest_mime, data)
         elif name.startswith('mathjax/'):
             from calibre.gui2.viewer.mathjax import monkeypatch_mathjax
             if name == 'mathjax/manifest.json':
diff --git a/src/calibre/srv/render_book.py b/src/calibre/srv/render_book.py
index aa7be19568..12f23bba9c 100644
--- a/src/calibre/srv/render_book.py
+++ b/src/calibre/srv/render_book.py
@@ -201,6 +201,7 @@ class Container(ContainerBase):
         self.book_render_data = data = {
             'version': RENDER_VERSION,
             'toc':toc,
+            'book_format': book_fmt,
             'spine':spine,
             'link_uid': uuid4(),
             'book_hash': book_hash,