diff --git a/Telegram/Resources/langs/lang.strings b/Telegram/Resources/langs/lang.strings
index cd4222eb7..8fd8a81e1 100644
--- a/Telegram/Resources/langs/lang.strings
+++ b/Telegram/Resources/langs/lang.strings
@@ -1149,6 +1149,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 "lng_media_size_limit" = "Limit by size";
 "lng_media_size_up_to" = "up to {size}";
 "lng_media_chat_background" = "Chat background";
+"lng_media_color_theme" = "Color theme";
 
 "lng_emoji_category1" = "People";
 "lng_emoji_category2" = "Nature";
diff --git a/Telegram/SourceFiles/data/data_document.cpp b/Telegram/SourceFiles/data/data_document.cpp
index a599c717f..89c7b0894 100644
--- a/Telegram/SourceFiles/data/data_document.cpp
+++ b/Telegram/SourceFiles/data/data_document.cpp
@@ -650,6 +650,7 @@ void DocumentData::validateGoodThumbnail() {
 	if (!isVideoFile()
 		&& !isAnimation()
 		&& !isWallPaper()
+		&& !isTheme()
 		&& (!sticker() || !sticker()->animated)) {
 		_goodThumbnail = nullptr;
 	} else if (!_goodThumbnail && hasRemoteLocation()) {
@@ -1470,7 +1471,8 @@ bool DocumentData::isGifv() const {
 
 bool DocumentData::isTheme() const {
 	return
-		_filename.endsWith(
+		_mimeString == qstr("application/x-tgtheme-tdesktop")
+		|| _filename.endsWith(
 			qstr(".tdesktop-theme"),
 			Qt::CaseInsensitive)
 		|| _filename.endsWith(
diff --git a/Telegram/SourceFiles/data/data_document_good_thumbnail.cpp b/Telegram/SourceFiles/data/data_document_good_thumbnail.cpp
index 39349a567..d2ac8ecab 100644
--- a/Telegram/SourceFiles/data/data_document_good_thumbnail.cpp
+++ b/Telegram/SourceFiles/data/data_document_good_thumbnail.cpp
@@ -10,8 +10,10 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_session.h"
 #include "data/data_document.h"
 #include "data/data_file_origin.h"
+#include "data/data_cloud_themes.h"
 #include "media/clip/media_clip_reader.h"
 #include "lottie/lottie_animation.h"
+#include "window/themes/window_theme_preview.h"
 #include "main/main_session.h"
 
 #include <QtCore/QBuffer>
@@ -27,6 +29,7 @@ enum class FileType {
 	Video,
 	AnimatedSticker,
 	WallPaper,
+	Theme,
 };
 
 QImage Prepare(
@@ -37,6 +40,8 @@ QImage Prepare(
 		return ::Media::Clip::PrepareForSending(path, data).thumbnail;
 	} else if (type == FileType::AnimatedSticker) {
 		return Lottie::ReadThumbnail(Lottie::ReadContent(data, path));
+	} else if (type == FileType::Theme) {
+		return Window::Theme::GeneratePreview(data, path);
 	}
 	const auto validateSize = [](QSize size) {
 		return (size.width() + size.height()) < 10'000;
@@ -78,6 +83,8 @@ void GoodThumbSource::generate(base::binary_guard &&guard) {
 	const auto data = _document->data();
 	const auto type = _document->isWallPaper()
 		? FileType::WallPaper
+		: _document->isTheme()
+		? FileType::Theme
 		: _document->sticker()
 		? FileType::AnimatedSticker
 		: FileType::Video;
@@ -143,13 +150,13 @@ void GoodThumbSource::ready(
 				_document->goodThumbnailCacheKey(),
 				Storage::Cache::Database::TaggedValue{
 					std::move(bytes),
-					Data::kImageCacheTag });
+					kImageCacheTag });
 		}
 		Auth().downloaderTaskFinished().notify();
 	});
 }
 
-void GoodThumbSource::load(Data::FileOrigin origin) {
+void GoodThumbSource::load(FileOrigin origin) {
 	if (loading() || _empty) {
 		return;
 	}
@@ -178,7 +185,7 @@ void GoodThumbSource::load(Data::FileOrigin origin) {
 		std::move(callback));
 }
 
-void GoodThumbSource::loadEvenCancelled(Data::FileOrigin origin) {
+void GoodThumbSource::loadEvenCancelled(FileOrigin origin) {
 	_empty = false;
 	load(origin);
 }
@@ -193,7 +200,7 @@ void GoodThumbSource::unload() {
 }
 
 void GoodThumbSource::automaticLoad(
-	Data::FileOrigin origin,
+	FileOrigin origin,
 	const HistoryItem *item) {
 }
 
@@ -235,7 +242,7 @@ void GoodThumbSource::setDelayedStorageLocation(
 	const StorageImageLocation &location) {
 }
 
-void GoodThumbSource::performDelayedLoad(Data::FileOrigin origin) {
+void GoodThumbSource::performDelayedLoad(FileOrigin origin) {
 }
 
 bool GoodThumbSource::isDelayedStorageImage() const {
diff --git a/Telegram/SourceFiles/data/data_document_good_thumbnail.h b/Telegram/SourceFiles/data/data_document_good_thumbnail.h
index 861102d21..58b53e384 100644
--- a/Telegram/SourceFiles/data/data_document_good_thumbnail.h
+++ b/Telegram/SourceFiles/data/data_document_good_thumbnail.h
@@ -17,13 +17,13 @@ class GoodThumbSource : public Images::Source {
 public:
 	explicit GoodThumbSource(not_null<DocumentData*> document);
 
-	void load(Data::FileOrigin origin) override;
-	void loadEvenCancelled(Data::FileOrigin origin) override;
+	void load(FileOrigin origin) override;
+	void loadEvenCancelled(FileOrigin origin) override;
 	QImage takeLoaded() override;
 	void unload() override;
 
 	void automaticLoad(
-		Data::FileOrigin origin,
+		FileOrigin origin,
 		const HistoryItem *item) override;
 	void automaticLoadSettingsChanged() override;
 
@@ -38,7 +38,7 @@ public:
 	std::optional<Storage::Cache::Key> cacheKey() override;
 	void setDelayedStorageLocation(
 		const StorageImageLocation &location) override;
-	void performDelayedLoad(Data::FileOrigin origin) override;
+	void performDelayedLoad(FileOrigin origin) override;
 	bool isDelayedStorageImage() const override;
 	void setImageBytes(const QByteArray &bytes) override;
 
diff --git a/Telegram/SourceFiles/data/data_file_origin.cpp b/Telegram/SourceFiles/data/data_file_origin.cpp
index 9ff88180c..b2932a5b9 100644
--- a/Telegram/SourceFiles/data/data_file_origin.cpp
+++ b/Telegram/SourceFiles/data/data_file_origin.cpp
@@ -51,6 +51,9 @@ struct FileReferenceAccumulator {
 			if (const auto document = data.vdocument()) {
 				push(*document);
 			}
+			if (const auto documents = data.vdocuments()) {
+				push(*documents);
+			}
 			if (const auto photo = data.vphoto()) {
 				push(*photo);
 			}
diff --git a/Telegram/SourceFiles/data/data_media_types.cpp b/Telegram/SourceFiles/data/data_media_types.cpp
index 7e49fdf9d..7c1c9636c 100644
--- a/Telegram/SourceFiles/data/data_media_types.cpp
+++ b/Telegram/SourceFiles/data/data_media_types.cpp
@@ -23,6 +23,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/view/media/history_view_call.h"
 #include "history/view/media/history_view_web_page.h"
 #include "history/view/media/history_view_poll.h"
+#include "history/view/media/history_view_theme_document.h"
 #include "ui/image/image.h"
 #include "ui/image/image_source.h"
 #include "ui/text_options.h"
@@ -779,6 +780,10 @@ std::unique_ptr<HistoryView::Media> MediaFile::createView(
 			message,
 			realParent,
 			_document);
+	} else if (_document->isTheme() && _document->hasThumbnail()) {
+		return std::make_unique<HistoryView::ThemeDocument>(
+			message,
+			_document);
 	}
 	return std::make_unique<HistoryView::Document>(message, _document);
 }
diff --git a/Telegram/SourceFiles/data/data_session.cpp b/Telegram/SourceFiles/data/data_session.cpp
index 30a4ad1ce..897ef57a6 100644
--- a/Telegram/SourceFiles/data/data_session.cpp
+++ b/Telegram/SourceFiles/data/data_session.cpp
@@ -2762,6 +2762,17 @@ void Session::webpageApplyFields(
 	const auto pendingTill = TimeId(0);
 	const auto photo = data.vphoto();
 	const auto document = data.vdocument();
+	const auto lookupThemeDocument = [&]() -> DocumentData* {
+		if (const auto documents = data.vdocuments()) {
+			for (const auto &document : documents->v) {
+				const auto processed = processDocument(document);
+				if (processed->isTheme()) {
+					return processed;
+				}
+			}
+		}
+		return nullptr;
+	};
 	webpageApplyFields(
 		page,
 		ParseWebPageType(data),
@@ -2771,7 +2782,7 @@ void Session::webpageApplyFields(
 		qs(data.vtitle().value_or_empty()),
 		description,
 		photo ? processPhoto(*photo).get() : nullptr,
-		document ? processDocument(*document).get() : nullptr,
+		document ? processDocument(*document).get() : lookupThemeDocument(),
 		WebPageCollage(data),
 		data.vduration().value_or_empty(),
 		qs(data.vauthor().value_or_empty()),
diff --git a/Telegram/SourceFiles/data/data_web_page.cpp b/Telegram/SourceFiles/data/data_web_page.cpp
index afc40f445..d4818683b 100644
--- a/Telegram/SourceFiles/data/data_web_page.cpp
+++ b/Telegram/SourceFiles/data/data_web_page.cpp
@@ -139,6 +139,8 @@ WebPageType ParseWebPageType(const MTPDwebPage &page) {
 		return WebPageType::Profile;
 	} else if (type == qstr("telegram_background")) {
 		return WebPageType::WallPaper;
+	} else if (type == qstr("telegram_theme")) {
+		return WebPageType::Theme;
 	} else if (page.vcached_page()) {
 		return WebPageType::ArticleWithIV;
 	} else {
diff --git a/Telegram/SourceFiles/data/data_web_page.h b/Telegram/SourceFiles/data/data_web_page.h
index 30fb70348..f3e6dfbae 100644
--- a/Telegram/SourceFiles/data/data_web_page.h
+++ b/Telegram/SourceFiles/data/data_web_page.h
@@ -15,6 +15,7 @@ enum class WebPageType {
 	Video,
 	Profile,
 	WallPaper,
+	Theme,
 	Article,
 	ArticleWithIV,
 };
diff --git a/Telegram/SourceFiles/history/history.style b/Telegram/SourceFiles/history/history.style
index 9bc5a7d7b..a5c3fc442 100644
--- a/Telegram/SourceFiles/history/history.style
+++ b/Telegram/SourceFiles/history/history.style
@@ -18,6 +18,7 @@ maxVideoMessageSize: 240px;
 maxSignatureSize: 144px;
 maxWallPaperWidth: 160px;
 maxWallPaperHeight: 240px;
+historyThemeSize: size(309px, 200px);
 
 historyMinimalWidth: 380px;
 
diff --git a/Telegram/SourceFiles/history/view/media/history_view_media_common.cpp b/Telegram/SourceFiles/history/view/media/history_view_media_common.cpp
index cbf367390..8d16dcee4 100644
--- a/Telegram/SourceFiles/history/view/media/history_view_media_common.cpp
+++ b/Telegram/SourceFiles/history/view/media/history_view_media_common.cpp
@@ -16,7 +16,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "history/view/media/history_view_document.h"
 #include "history/view/media/history_view_sticker.h"
 #include "history/view/media/history_view_video.h"
-#include "history/view/media/history_view_wall_paper.h"
+#include "history/view/media/history_view_theme_document.h"
 #include "styles/style_history.h"
 
 namespace HistoryView {
@@ -80,8 +80,8 @@ std::unique_ptr<Media> CreateAttach(
 				parent,
 				parent->data(),
 				document);
-		} else if (document->isWallPaper()) {
-			return std::make_unique<WallPaper>(
+		} else if (document->isWallPaper() || document->isTheme()) {
+			return std::make_unique<ThemeDocument>(
 				parent,
 				document,
 				webpageUrl);
diff --git a/Telegram/SourceFiles/history/view/media/history_view_wall_paper.cpp b/Telegram/SourceFiles/history/view/media/history_view_theme_document.cpp
similarity index 84%
rename from Telegram/SourceFiles/history/view/media/history_view_wall_paper.cpp
rename to Telegram/SourceFiles/history/view/media/history_view_theme_document.cpp
index 0701101ac..c0265dfac 100644
--- a/Telegram/SourceFiles/history/view/media/history_view_wall_paper.cpp
+++ b/Telegram/SourceFiles/history/view/media/history_view_theme_document.cpp
@@ -5,7 +5,7 @@ the official desktop application for the Telegram messaging service.
 For license and copyright information please follow this link:
 https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 */
-#include "history/view/media/history_view_wall_paper.h"
+#include "history/view/media/history_view_theme_document.h"
 
 #include "layout.h"
 #include "history/history_item.h"
@@ -19,22 +19,24 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 namespace HistoryView {
 
-WallPaper::WallPaper(
+ThemeDocument::ThemeDocument(
 	not_null<Element*> parent,
 	not_null<DocumentData*> document,
 	const QString &url)
 : File(parent, parent->data())
 , _data(document) {
-	Expects(_data->hasThumbnail());
+	Expects(_data->hasThumbnail() || _data->isTheme());
 
-	fillPatternFieldsFrom(url);
+	if (_data->isWallPaper()) {
+		fillPatternFieldsFrom(url);
+	}
 
-	_data->thumbnail()->load(parent->data()->fullId());
+	_data->loadThumbnail(_parent->data()->fullId());
 	setDocumentLinks(_data, parent->data());
 	setStatusSize(FileStatusSizeReady, _data->size, -1, 0);
 }
 
-void WallPaper::fillPatternFieldsFrom(const QString &url) {
+void ThemeDocument::fillPatternFieldsFrom(const QString &url) {
 	const auto paramsPosition = url.indexOf('?');
 	if (paramsPosition < 0) {
 		return;
@@ -49,7 +51,10 @@ void WallPaper::fillPatternFieldsFrom(const QString &url) {
 	_background = paper.backgroundColor().value_or(kDefaultBackground);
 }
 
-QSize WallPaper::countOptimalSize() {
+QSize ThemeDocument::countOptimalSize() {
+	if (_data->isTheme()) {
+		return st::historyThemeSize;
+	}
 	auto tw = ConvertScale(_data->thumbnail()->width());
 	auto th = ConvertScale(_data->thumbnail()->height());
 	if (!tw || !th) {
@@ -66,7 +71,12 @@ QSize WallPaper::countOptimalSize() {
 	return { maxWidth, minHeight };
 }
 
-QSize WallPaper::countCurrentSize(int newWidth) {
+QSize ThemeDocument::countCurrentSize(int newWidth) {
+	if (_data->isTheme()) {
+		_pixw = st::historyThemeSize.width();
+		_pixh = st::historyThemeSize.height();
+		return st::historyThemeSize;
+	}
 	auto tw = ConvertScale(_data->thumbnail()->width());
 	auto th = ConvertScale(_data->thumbnail()->height());
 	if (!tw || !th) {
@@ -86,7 +96,7 @@ QSize WallPaper::countCurrentSize(int newWidth) {
 	return { newWidth, newHeight };
 }
 
-void WallPaper::draw(Painter &p, const QRect &r, TextSelection selection, crl::time ms) const {
+void ThemeDocument::draw(Painter &p, const QRect &r, TextSelection selection, crl::time ms) const {
 	if (width() < st::msgPadding.left() + st::msgPadding.right() + 1) return;
 
 	_data->automaticLoad(_realParent->fullId(), _parent->data());
@@ -166,7 +176,7 @@ void WallPaper::draw(Painter &p, const QRect &r, TextSelection selection, crl::t
 	}
 }
 
-void WallPaper::validateThumbnail() const {
+void ThemeDocument::validateThumbnail() const {
 	if (_thumbnailGood > 0) {
 		return;
 	}
@@ -179,7 +189,7 @@ void WallPaper::validateThumbnail() const {
 			good->load({});
 		}
 	}
-	if (_thumbnailGood >= 0) {
+	if (_thumbnailGood >= 0 || !_data->thumbnail()) {
 		return;
 	}
 	if (_data->thumbnail()->loaded()) {
@@ -191,11 +201,12 @@ void WallPaper::validateThumbnail() const {
 	}
 }
 
-void WallPaper::prepareThumbnailFrom(
+void ThemeDocument::prepareThumbnailFrom(
 		not_null<Image*> image,
 		int good) const {
 	Expects(_thumbnailGood <= good);
 
+	const auto isTheme = _data->isTheme();
 	const auto isPattern = _data->isPatternWallPaper();
 	auto options = Images::Option::Smooth
 		| (good >= 0 ? Images::Option(0) : Images::Option::Blurred)
@@ -203,8 +214,8 @@ void WallPaper::prepareThumbnailFrom(
 			? Images::Option::TransparentBackground
 			: Images::Option(0));
 	auto original = image->original();
-	auto tw = ConvertScale(_data->thumbnail()->width());
-	auto th = ConvertScale(_data->thumbnail()->height());
+	auto tw = isTheme ? _pixw : ConvertScale(_data->thumbnail()->width());
+	auto th = isTheme ? _pixh : ConvertScale(_data->thumbnail()->height());
 	if (!tw || !th) {
 		tw = th = 1;
 	}
@@ -226,7 +237,7 @@ void WallPaper::prepareThumbnailFrom(
 	_thumbnailGood = good;
 }
 
-TextState WallPaper::textState(QPoint point, StateRequest request) const {
+TextState ThemeDocument::textState(QPoint point, StateRequest request) const {
 	auto result = TextState(_parent);
 
 	if (width() < st::msgPadding.left() + st::msgPadding.right() + 1) {
@@ -248,24 +259,24 @@ TextState WallPaper::textState(QPoint point, StateRequest request) const {
 	return result;
 }
 
-float64 WallPaper::dataProgress() const {
+float64 ThemeDocument::dataProgress() const {
 	return _data->progress();
 }
 
-bool WallPaper::dataFinished() const {
+bool ThemeDocument::dataFinished() const {
 	return !_data->loading()
 		&& (!_data->uploading() || _data->waitingForAlbum());
 }
 
-bool WallPaper::dataLoaded() const {
+bool ThemeDocument::dataLoaded() const {
 	return _data->loaded();
 }
 
-bool WallPaper::isReadyForOpen() const {
+bool ThemeDocument::isReadyForOpen() const {
 	return _data->loaded();
 }
 
-QString WallPaper::additionalInfoString() const {
+QString ThemeDocument::additionalInfoString() const {
 	// This will force message info (time) to be displayed below
 	// this attachment in WebPage media.
 	static auto result = QString(" ");
diff --git a/Telegram/SourceFiles/history/view/media/history_view_wall_paper.h b/Telegram/SourceFiles/history/view/media/history_view_theme_document.h
similarity index 94%
rename from Telegram/SourceFiles/history/view/media/history_view_wall_paper.h
rename to Telegram/SourceFiles/history/view/media/history_view_theme_document.h
index e61cea573..421280994 100644
--- a/Telegram/SourceFiles/history/view/media/history_view_wall_paper.h
+++ b/Telegram/SourceFiles/history/view/media/history_view_theme_document.h
@@ -11,9 +11,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 namespace HistoryView {
 
-class WallPaper : public File {
+class ThemeDocument : public File {
 public:
-	WallPaper(
+	ThemeDocument(
 		not_null<Element*> parent,
 		not_null<DocumentData*> document,
 		const QString &url = QString());
@@ -59,6 +59,8 @@ private:
 	int _pixh = 1;
 	mutable QPixmap _thumbnail;
 	mutable int _thumbnailGood = -1; // -1 inline, 0 thumbnail, 1 good
+
+	// For wallpaper documents.
 	QColor _background;
 	int _intensity = 0;
 
diff --git a/Telegram/SourceFiles/history/view/media/history_view_web_page.cpp b/Telegram/SourceFiles/history/view/media/history_view_web_page.cpp
index 2bdbd2d6c..adb6d7ab2 100644
--- a/Telegram/SourceFiles/history/view/media/history_view_web_page.cpp
+++ b/Telegram/SourceFiles/history/view/media/history_view_web_page.cpp
@@ -129,7 +129,9 @@ QSize WebPage::countOptimalSize() {
 		_openl = previewOfHiddenUrl
 			? std::make_shared<HiddenUrlClickHandler>(_data->url)
 			: std::make_shared<UrlClickHandler>(_data->url, true);
-		if (_data->document && _data->document->isWallPaper()) {
+		if (_data->document
+			&& (_data->document->isWallPaper()
+				|| _data->document->isTheme())) {
 			_openl = std::make_shared<DocumentWrappedClickHandler>(
 				std::move(_openl),
 				_data->document,
@@ -652,7 +654,7 @@ ClickHandlerPtr WebPage::replaceAttachLink(
 		return link;
 	}
 	if (_data->document) {
-		if (_data->document->isWallPaper()) {
+		if (_data->document->isWallPaper() || _data->document->isTheme()) {
 			return _openl;
 		}
 	} else if (_data->photo) {
@@ -674,7 +676,7 @@ TextSelection WebPage::adjustSelection(TextSelection selection, TextSelectType t
 	if ((!_titleLines && !_descriptionLines) || selection.to <= _siteName.length()) {
 		return _siteName.adjustSelection(selection, type);
 	}
-	
+
 	auto titleSelection = _title.adjustSelection(toTitleSelection(selection), type);
 	if ((!_siteNameLines && !_descriptionLines) || (selection.from >= _siteName.length() && selection.to <= _description.length())) {
 		return fromTitleSelection(titleSelection);
@@ -708,7 +710,7 @@ void WebPage::clickHandlerPressedChanged(const ClickHandlerPtr &p, bool pressed)
 bool WebPage::enforceBubbleWidth() const {
 	return (_attach != nullptr)
 		&& (_data->document != nullptr)
-		&& _data->document->isWallPaper();
+		&& (_data->document->isWallPaper() || _data->document->isTheme());
 }
 
 void WebPage::playAnimation(bool autoplay) {
@@ -779,6 +781,8 @@ int WebPage::bottomInfoPadding() const {
 QString WebPage::displayedSiteName() const {
 	return (_data->document && _data->document->isWallPaper())
 		? tr::lng_media_chat_background(tr::now)
+		: (_data->document && _data->document->isWallPaper())
+		? tr::lng_media_color_theme(tr::now)
 		: _data->siteName;
 }
 
diff --git a/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp b/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp
index 06f3f7c2c..50d7ccf50 100644
--- a/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp
+++ b/Telegram/SourceFiles/media/view/media_view_overlay_widget.cpp
@@ -2251,7 +2251,12 @@ void OverlayWidget::initThemePreview() {
 	const auto id = _themePreviewId = rand_value<uint64>();
 	const auto weak = make_weak(this);
 	crl::async([=, data = std::move(current)]() mutable {
-		auto preview = GeneratePreview(bytes, path, fields, std::move(data));
+		auto preview = GeneratePreview(
+			bytes,
+			path,
+			fields,
+			std::move(data),
+			Window::Theme::PreviewType::Extended);
 		crl::on_main(weak, [=, result = std::move(preview)]() mutable {
 			if (id != _themePreviewId) {
 				return;
diff --git a/Telegram/SourceFiles/storage/localimageloader.cpp b/Telegram/SourceFiles/storage/localimageloader.cpp
index 0a94bdbd9..28da2fc8a 100644
--- a/Telegram/SourceFiles/storage/localimageloader.cpp
+++ b/Telegram/SourceFiles/storage/localimageloader.cpp
@@ -21,6 +21,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "lang/lang_keys.h"
 #include "storage/file_download.h"
 #include "storage/storage_media_prepare.h"
+#include "window/themes/window_theme_preview.h"
 #include "mainwidget.h"
 #include "mainwindow.h"
 #include "main/main_session.h"
@@ -78,13 +79,6 @@ PreparedFileThumbnail PrepareFileThumbnail(QImage &&original) {
 	return result;
 }
 
-PreparedFileThumbnail PrepareAnimatedStickerThumbnail(
-		const QString &file,
-		const QByteArray &bytes) {
-	return PrepareFileThumbnail(
-		Lottie::ReadThumbnail(Lottie::ReadContent(bytes, file)));
-}
-
 bool FileThumbnailUploadRequired(const QString &filemime, int32 filesize) {
 	constexpr auto kThumbnailUploadBySize = 5 * 1024 * 1024;
 	const auto kThumbnailKnownMimes = {
@@ -818,6 +812,15 @@ void FileLoadTask::process() {
 			}
 
 			thumbnail = PrepareFileThumbnail(std::move(video->thumbnail));
+		} else if (filemime == qstr("application/x-tdesktop-theme")
+			|| filemime == qstr("application/x-tgtheme-tdesktop")) {
+			goodThumbnail = Window::Theme::GeneratePreview(_content, _filepath);
+			if (!goodThumbnail.isNull()) {
+				QBuffer buffer(&goodThumbnailBytes);
+				goodThumbnail.save(&buffer, "JPG", kThumbnailQuality);
+
+				thumbnail = PrepareFileThumbnail(base::duplicate(goodThumbnail));
+			}
 		}
 	}
 
diff --git a/Telegram/SourceFiles/window/themes/window_theme_editor_box.cpp b/Telegram/SourceFiles/window/themes/window_theme_editor_box.cpp
index ed14ff72d..c9c952322 100644
--- a/Telegram/SourceFiles/window/themes/window_theme_editor_box.cpp
+++ b/Telegram/SourceFiles/window/themes/window_theme_editor_box.cpp
@@ -465,15 +465,26 @@ SendMediaReady PrepareThemeMedia(
 	PreparedPhotoThumbs thumbnails;
 	QVector<MTPPhotoSize> sizes;
 
-	//const auto push = [&](const char *type, QImage &&image) {
-	//	sizes.push_back(MTP_photoSize(
-	//		MTP_string(type),
-	//		MTP_fileLocationToBeDeprecated(MTP_long(0), MTP_int(0)),
-	//		MTP_int(image.width()),
-	//		MTP_int(image.height()), MTP_int(0)));
-	//	thumbnails.emplace(type[0], std::move(image));
-	//};
-	//push("s", scaled(320));
+	auto thumbnail = GeneratePreview(content, QString()).scaled(
+		320,
+		320,
+		Qt::KeepAspectRatio,
+		Qt::SmoothTransformation);
+	auto thumbnailBytes = QByteArray();
+	{
+		QBuffer buffer(&thumbnailBytes);
+		thumbnail.save(&buffer, "JPG", 87);
+	}
+
+	const auto push = [&](const char *type, QImage &&image) {
+		sizes.push_back(MTP_photoSize(
+			MTP_string(type),
+			MTP_fileLocationToBeDeprecated(MTP_long(0), MTP_int(0)),
+			MTP_int(image.width()),
+			MTP_int(image.height()), MTP_int(0)));
+		thumbnails.emplace(type[0], std::move(image));
+	};
+	push("s", std::move(thumbnail));
 
 	const auto filename = File::NameFromUserString(name)
 		+ qsl(".tdesktop-theme");
@@ -506,7 +517,7 @@ SendMediaReady PrepareThemeMedia(
 		MTP_photoEmpty(MTP_long(0)),
 		thumbnails,
 		document,
-		QByteArray(),
+		thumbnailBytes,
 		0);
 }
 
@@ -520,7 +531,7 @@ Fn<void()> SavePreparedTheme(
 		Fn<void(SaveErrorType,QString)> fail) {
 	Expects(window->account().sessionExists());
 
-	using Storage::UploadedDocument;
+	using Storage::UploadedThumbDocument;
 	struct State {
 		FullMsgId id;
 		bool generating = false;
@@ -539,6 +550,7 @@ Fn<void()> SavePreparedTheme(
 
 	const auto creating = !fields.id
 		|| (fields.createdBy != session->userId());
+	const auto oldDocumentId = creating ? 0 : fields.documentId;
 	const auto changed = (parsed.background != originalParsed.background)
 		|| (parsed.tiled != originalParsed.tiled)
 		|| PaletteChanged(parsed.palette, originalParsed.palette, fields);
@@ -602,11 +614,11 @@ Fn<void()> SavePreparedTheme(
 		}).send();
 	};
 
-	const auto uploadTheme = [=](const UploadedDocument &data) {
+	const auto uploadTheme = [=](const UploadedThumbDocument &data) {
 		state->requestId = api->request(MTPaccount_UploadTheme(
-			MTP_flags(0),
+			MTP_flags(MTPaccount_UploadTheme::Flag::f_thumb),
 			data.file,
-			MTPInputFile(), // thumb
+			data.thumb,
 			MTP_string(state->filename),
 			MTP_string("application/x-tgtheme-tdesktop")
 		)).done([=](const MTPDocument &result) {
@@ -625,10 +637,10 @@ Fn<void()> SavePreparedTheme(
 		state->filename = media.filename;
 		state->themeContent = theme;
 
-		session->uploader().documentReady(
-		) | rpl::filter([=](const UploadedDocument &data) {
+		session->uploader().thumbDocumentReady(
+		) | rpl::filter([=](const UploadedThumbDocument &data) {
 			return data.fullId == state->id;
-		}) | rpl::start_with_next([=](const UploadedDocument &data) {
+		}) | rpl::start_with_next([=](const UploadedThumbDocument &data) {
 			uploadTheme(data);
 		}, state->lifetime);
 
diff --git a/Telegram/SourceFiles/window/themes/window_theme_preview.cpp b/Telegram/SourceFiles/window/themes/window_theme_preview.cpp
index 56eb4979d..c72fa7049 100644
--- a/Telegram/SourceFiles/window/themes/window_theme_preview.cpp
+++ b/Telegram/SourceFiles/window/themes/window_theme_preview.cpp
@@ -83,9 +83,12 @@ QString fillLetters(const QString &name) {
 
 class Generator {
 public:
-	Generator(const Instance &theme, CurrentData &&current);
+	Generator(
+		const Instance &theme,
+		CurrentData &&current,
+		PreviewType type);
 
-	QImage generate();
+	[[nodiscard]] QImage generate();
 
 private:
 	enum class Status {
@@ -131,6 +134,7 @@ private:
 		Ui::Text::String replyText = { st::msgMinWidth };
 	};
 
+	[[nodiscard]] bool extended() const;
 	void prepare();
 
 	void addRow(QString name, int peerIndex, QString date, QString text);
@@ -162,7 +166,8 @@ private:
 
 	const Instance &_theme;
 	const style::palette &_palette;
-	CurrentData _current;
+	const CurrentData _current;
+	const PreviewType _type;
 	Painter *_p = nullptr;
 
 	QRect _rect;
@@ -188,10 +193,19 @@ private:
 
 };
 
+bool Generator::extended() const {
+	return (_type == PreviewType::Extended);
+}
+
 void Generator::prepare() {
-	_rect = QRect(0, 0, st::themePreviewMargin.left() + st::themePreviewSize.width() + st::themePreviewMargin.right(), st::themePreviewMargin.top() + st::themePreviewSize.height() + st::themePreviewMargin.bottom());
-	_inner = _rect.marginsRemoved(st::themePreviewMargin);
-	_body = _inner.marginsRemoved(QMargins(0, Platform::PreviewTitleHeight(), 0, 0));
+	const auto size = extended()
+		? QRect(
+			QPoint(),
+			st::themePreviewSize).marginsAdded(st::themePreviewMargin).size()
+		: st::themePreviewSize;
+	_rect = QRect(QPoint(), size);
+	_inner = extended() ? _rect.marginsRemoved(st::themePreviewMargin) : _rect;
+	_body = extended() ? _inner.marginsRemoved(QMargins(0, Platform::PreviewTitleHeight(), 0, 0)) : _inner;
 	_dialogs = QRect(_body.x(), _body.y(), st::themePreviewDialogsWidth, _body.height());
 	_dialogsList = _dialogs.marginsRemoved(QMargins(0, st::dialogsFilterPadding.y() + st::dialogsMenuToggle.height + st::dialogsFilterPadding.y(), 0, st::dialogsPadding.y()));
 	_topBar = QRect(_dialogs.x() + _dialogs.width(), _dialogs.y(), _body.width() - _dialogs.width(), st::topBarHeight);
@@ -339,10 +353,14 @@ void Generator::generateData() {
 	_bubbles.back().replyText.setText(st::messageTextStyle, "Mark Twain said that " + QString() + QChar(9757) + QChar(55356) + QChar(57339), Ui::DialogTextOptions());
 }
 
-Generator::Generator(const Instance &theme, CurrentData &&current)
+Generator::Generator(
+	const Instance &theme,
+	CurrentData &&current,
+	PreviewType type)
 : _theme(theme)
 , _palette(_theme.palette)
-, _current(std::move(current)) {
+, _current(std::move(current))
+, _type(type) {
 }
 
 QImage Generator::generate() {
@@ -368,7 +386,9 @@ QImage Generator::generate() {
 		paintDialogs();
 		paintHistoryShadows();
 	}
-	Platform::PreviewWindowFramePaint(result, _palette, _body, _rect.width());
+	if (extended()) {
+		Platform::PreviewWindowFramePaint(result, _palette, _body, _rect.width());
+	}
 
 	return result;
 }
@@ -944,18 +964,32 @@ std::unique_ptr<Preview> GeneratePreview(
 		const QByteArray &bytes,
 		const QString &filepath,
 		const Data::CloudTheme &cloud,
-		CurrentData &&data) {
+		CurrentData &&data,
+		PreviewType type) {
 	auto result = PreviewFromFile(bytes, filepath, cloud);
 	if (!result) {
 		return nullptr;
 	}
 	result->preview = Generator(
 		result->instance,
-		std::move(data)
+		std::move(data),
+		type
 	).generate();
 	return result;
 }
 
+QImage GeneratePreview(
+		const QByteArray &bytes,
+		const QString &filepath) {
+	const auto preview = GeneratePreview(
+		bytes,
+		filepath,
+		Data::CloudTheme(),
+		CurrentData{ Data::ThemeWallPaper().id() },
+		PreviewType::Normal);
+	return preview ? preview->preview : QImage();
+}
+
 int DefaultPreviewTitleHeight() {
 	return st::titleHeight;
 }
diff --git a/Telegram/SourceFiles/window/themes/window_theme_preview.h b/Telegram/SourceFiles/window/themes/window_theme_preview.h
index 0ab28e503..008763286 100644
--- a/Telegram/SourceFiles/window/themes/window_theme_preview.h
+++ b/Telegram/SourceFiles/window/themes/window_theme_preview.h
@@ -17,11 +17,16 @@ namespace Window {
 namespace Theme {
 
 struct CurrentData {
-	int32 backgroundId = 0;
+	WallPaperId backgroundId = 0;
 	QImage backgroundImage;
 	bool backgroundTiled = false;
 };
 
+enum class PreviewType {
+	Normal,
+	Extended,
+};
+
 [[nodiscard]] QString CachedThemePath(uint64 documentId);
 
 std::unique_ptr<Preview> PreviewFromFile(
@@ -32,7 +37,11 @@ std::unique_ptr<Preview> GeneratePreview(
 	const QByteArray &bytes,
 	const QString &filepath,
 	const Data::CloudTheme &cloud,
-	CurrentData &&data);
+	CurrentData &&data,
+	PreviewType type);
+QImage GeneratePreview(
+	const QByteArray &bytes,
+	const QString &filepath);
 
 int DefaultPreviewTitleHeight();
 void DefaultPreviewWindowFramePaint(
diff --git a/Telegram/gyp/telegram_sources.txt b/Telegram/gyp/telegram_sources.txt
index 047385623..4be242198 100644
--- a/Telegram/gyp/telegram_sources.txt
+++ b/Telegram/gyp/telegram_sources.txt
@@ -316,10 +316,10 @@
 <(src_loc)/history/view/media/history_view_poll.cpp
 <(src_loc)/history/view/media/history_view_sticker.h
 <(src_loc)/history/view/media/history_view_sticker.cpp
+<(src_loc)/history/view/media/history_view_theme_document.h
+<(src_loc)/history/view/media/history_view_theme_document.cpp
 <(src_loc)/history/view/media/history_view_video.h
 <(src_loc)/history/view/media/history_view_video.cpp
-<(src_loc)/history/view/media/history_view_wall_paper.h
-<(src_loc)/history/view/media/history_view_wall_paper.cpp
 <(src_loc)/history/view/media/history_view_web_page.h
 <(src_loc)/history/view/media/history_view_web_page.cpp
 <(src_loc)/history/view/history_view_compose_controls.cpp