diff --git a/src/librssguard/exceptions/feedrecognizedbutfailedexception.cpp b/src/librssguard/exceptions/feedrecognizedbutfailedexception.cpp
index 50762e80c..ae35cb720 100644
--- a/src/librssguard/exceptions/feedrecognizedbutfailedexception.cpp
+++ b/src/librssguard/exceptions/feedrecognizedbutfailedexception.cpp
@@ -2,4 +2,10 @@
 
 #include "exceptions/feedrecognizedbutfailedexception.h"
 
-FeedRecognizedButFailedException::FeedRecognizedButFailedException(const QString &message) : ApplicationException(message) {}
+FeedRecognizedButFailedException::FeedRecognizedButFailedException(const QString& message,
+                                                                   const QVariant& arbitrary_data)
+  : ApplicationException(message), m_arbitraryData(arbitrary_data) {}
+
+QVariant FeedRecognizedButFailedException::arbitraryData() const {
+  return m_arbitraryData;
+}
diff --git a/src/librssguard/exceptions/feedrecognizedbutfailedexception.h b/src/librssguard/exceptions/feedrecognizedbutfailedexception.h
index 71f8d65f5..af3228693 100644
--- a/src/librssguard/exceptions/feedrecognizedbutfailedexception.h
+++ b/src/librssguard/exceptions/feedrecognizedbutfailedexception.h
@@ -5,9 +5,16 @@
 
 #include "exceptions/applicationexception.h"
 
+#include <QVariant>
+
 class FeedRecognizedButFailedException : public ApplicationException {
   public:
-    explicit FeedRecognizedButFailedException(const QString& message = {});
+    explicit FeedRecognizedButFailedException(const QString& message = {}, const QVariant& arbitrary_data = {});
+
+    QVariant arbitraryData() const;
+
+  private:
+    QVariant m_arbitraryData;
 };
 
 #endif // UNRECOGNIZEDFEEDFORMATEXCEPTION_H
diff --git a/src/librssguard/network-web/basenetworkaccessmanager.cpp b/src/librssguard/network-web/basenetworkaccessmanager.cpp
index e1d18cd3a..7338c9c83 100644
--- a/src/librssguard/network-web/basenetworkaccessmanager.cpp
+++ b/src/librssguard/network-web/basenetworkaccessmanager.cpp
@@ -66,15 +66,18 @@ QNetworkReply* BaseNetworkAccessManager::createRequest(QNetworkAccessManager::Op
   // new_request.setMaximumRedirectsAllowed(0);
 
   new_request.setRawHeader(HTTP_HEADERS_COOKIE, QSL("JSESSIONID= ").toLocal8Bit());
+  /*
+    auto custom_ua = qApp->web()->customUserAgent();
 
-  auto custom_ua = qApp->web()->customUserAgent();
+    if (custom_ua.isEmpty()) {
+      new_request.setRawHeader(HTTP_HEADERS_USER_AGENT, HTTP_COMPLETE_USERAGENT);
+    }
+    else {
+      new_request.setRawHeader(HTTP_HEADERS_USER_AGENT, custom_ua.toLocal8Bit());
+    }
+  */
 
-  if (custom_ua.isEmpty()) {
-    new_request.setRawHeader(HTTP_HEADERS_USER_AGENT, HTTP_COMPLETE_USERAGENT);
-  }
-  else {
-    new_request.setRawHeader(HTTP_HEADERS_USER_AGENT, custom_ua.toLocal8Bit());
-  }
+  new_request.setRawHeader(HTTP_HEADERS_USER_AGENT, " ");
 
   auto reply = QNetworkAccessManager::createRequest(op, new_request, outgoingData);
   return reply;
diff --git a/src/librssguard/services/standard/definitions.h b/src/librssguard/services/standard/definitions.h
index ca83c539b..a35c27487 100644
--- a/src/librssguard/services/standard/definitions.h
+++ b/src/librssguard/services/standard/definitions.h
@@ -6,4 +6,17 @@
 #define FEED_INITIAL_OPML_PATTERN   "feeds-%1.opml"
 #define DEFAULT_ENCLOSURE_MIME_TYPE "image/jpg"
 
+#define ADVANCED_FEED_ADD_DIALOG_CODE 64
+
+#define RSS_REGEX_MATCHER      "<link[^>]+type=\"application\\/(?:rss\\+xml)\"[^>]*>"
+#define RSS_HREF_REGEX_MATCHER "href=\"([^\"]+)\""
+
+#define JSON_REGEX_MATCHER      "<link[^>]+type=\"application\\/(?:feed\\+json|json)\"[^>]*>"
+#define JSON_HREF_REGEX_MATCHER "href=\"([^\"]+)\""
+
+#define ATOM_REGEX_MATCHER      "<link[^>]+type=\"application\\/(?:atom\\+xml|rss\\+xml)\"[^>]*>"
+#define ATOM_HREF_REGEX_MATCHER "href=\"([^\"]+)\""
+
+#define GITHUB_URL_REGEX "github\\.com\\/(\\w+)\\/(\\w+)"
+
 #endif // STANDARD_DEFINITIONS_H
diff --git a/src/librssguard/services/standard/gui/formdiscoverfeeds.cpp b/src/librssguard/services/standard/gui/formdiscoverfeeds.cpp
index 778f68133..326b5573c 100644
--- a/src/librssguard/services/standard/gui/formdiscoverfeeds.cpp
+++ b/src/librssguard/services/standard/gui/formdiscoverfeeds.cpp
@@ -2,11 +2,13 @@
 
 #include "services/standard/gui/formdiscoverfeeds.h"
 
+#include "3rd-party/boolinq/boolinq.h"
 #include "gui/guiutilities.h"
 #include "miscellaneous/application.h"
 #include "miscellaneous/iconfactory.h"
 #include "services/abstract/category.h"
 #include "services/abstract/serviceroot.h"
+#include "services/standard/definitions.h"
 #include "services/standard/standardfeed.h"
 
 #include "services/standard/parsers/atomparser.h"
@@ -28,14 +30,20 @@ FormDiscoverFeeds::FormDiscoverFeeds(ServiceRoot* service_root,
 
   m_parsers = {new AtomParser({}), new RssParser({}), new RdfParser({}), new JsonParser({}), new SitemapParser({})};
 
+  m_btnGoAdvanced = m_ui.m_buttonBox->addButton(tr("Close && &advanced mode"), QDialogButtonBox::ButtonRole::NoRole);
   m_btnImportSelectedFeeds =
     m_ui.m_buttonBox->addButton(tr("Import selected feeds"), QDialogButtonBox::ButtonRole::ActionRole);
 
+  m_btnGoAdvanced
+    ->setToolTip(tr("Close this dialog and display dialog for adding individual feeds with advanced options."));
+
+  m_btnGoAdvanced->setIcon(qApp->icons()->fromTheme(QSL("system-upgrade")));
   m_btnImportSelectedFeeds->setIcon(qApp->icons()->fromTheme(QSL("document-import")));
   m_ui.m_btnDiscover->setIcon(qApp->icons()->fromTheme(QSL("system-search")));
 
   connect(m_ui.m_txtUrl->lineEdit(), &QLineEdit::textChanged, this, &FormDiscoverFeeds::onUrlChanged);
   connect(m_btnImportSelectedFeeds, &QPushButton::clicked, this, &FormDiscoverFeeds::importSelectedFeeds);
+  connect(m_btnGoAdvanced, &QPushButton::clicked, this, &FormDiscoverFeeds::userWantsAdvanced);
   connect(m_ui.m_btnDiscover, &QPushButton::clicked, this, &FormDiscoverFeeds::discoverFeeds);
 
   connect(&m_watcherLookup, &QFutureWatcher<QList<StandardFeed*>>::progressValueChanged, this, [=](int prog) {
@@ -145,6 +153,11 @@ void FormDiscoverFeeds::addSingleFeed(StandardFeed* feed) {
 
 void FormDiscoverFeeds::importSelectedFeeds() {}
 
+void FormDiscoverFeeds::userWantsAdvanced() {
+  setResult(ADVANCED_FEED_ADD_DIALOG_CODE);
+  close();
+}
+
 void FormDiscoverFeeds::loadDiscoveredFeeds(const QList<StandardFeed*>& feeds) {
   m_ui.m_pbDiscovery->setVisible(false);
   m_discoveredModel->setDiscoveredFeeds(feeds);
@@ -166,16 +179,27 @@ QVariant DiscoveredFeedsModel::data(const QModelIndex& index, int role) const {
   switch (role) {
     case Qt::ItemDataRole::DisplayRole: {
       if (index.column() == 0) {
-        return m_discoveredFeeds.at(index.row())->title();
+        return m_discoveredFeeds.at(index.row()).m_feed->title();
       }
       else {
-        return StandardFeed::typeToString(m_discoveredFeeds.at(index.row())->type());
+        return StandardFeed::typeToString(m_discoveredFeeds.at(index.row()).m_feed->type());
       }
     }
 
+    case Qt::ItemDataRole::CheckStateRole: {
+      if (index.column() == 0) {
+        return m_discoveredFeeds.at(index.row()).m_isChecked ? Qt::CheckState::Checked : Qt::CheckState::Unchecked;
+      }
+      else {
+        return {};
+      }
+
+      break;
+    }
+
     case Qt::ItemDataRole::DecorationRole: {
       if (index.column() == 0) {
-        return m_discoveredFeeds.at(index.row())->fullIcon();
+        return m_discoveredFeeds.at(index.row()).m_feed->fullIcon();
       }
     }
 
@@ -184,12 +208,18 @@ QVariant DiscoveredFeedsModel::data(const QModelIndex& index, int role) const {
   }
 }
 
-QList<StandardFeed*> DiscoveredFeedsModel::discoveredFeeds() const {
+QList<DiscoveredFeedsModel::FeedItem> DiscoveredFeedsModel::discoveredFeeds() const {
   return m_discoveredFeeds;
 }
 
-void DiscoveredFeedsModel::setDiscoveredFeeds(const QList<StandardFeed*>& newDiscoveredFeeds) {
-  m_discoveredFeeds = newDiscoveredFeeds;
+void DiscoveredFeedsModel::setDiscoveredFeeds(const QList<StandardFeed*>& feeds) {
+  auto std_feeds = boolinq::from(feeds)
+                     .select([](StandardFeed* fd) {
+                       return FeedItem{false, fd};
+                     })
+                     .toStdList();
+
+  m_discoveredFeeds = FROM_STD_LIST(QList<FeedItem>, std_feeds);
 
   emit layoutAboutToBeChanged();
   emit layoutChanged();
@@ -208,3 +238,17 @@ QVariant DiscoveredFeedsModel::headerData(int section, Qt::Orientation orientati
 
   return {};
 }
+
+Qt::ItemFlags DiscoveredFeedsModel::flags(const QModelIndex& index) const {
+  return index.column() == 0 ? Qt::ItemFlag::ItemIsUserCheckable | QAbstractListModel::flags(index)
+                             : QAbstractListModel::flags(index);
+}
+
+bool DiscoveredFeedsModel::setData(const QModelIndex& index, const QVariant& value, int role) {
+  if (role == Qt::ItemDataRole::CheckStateRole && index.column() == 0) {
+    m_discoveredFeeds[index.row()].m_isChecked = value.value<Qt::CheckState>() == Qt::CheckState::Checked;
+    return true;
+  }
+
+  return QAbstractListModel::setData(index, value, role);
+}
diff --git a/src/librssguard/services/standard/gui/formdiscoverfeeds.h b/src/librssguard/services/standard/gui/formdiscoverfeeds.h
index 2fdb1e98e..4d28b1beb 100644
--- a/src/librssguard/services/standard/gui/formdiscoverfeeds.h
+++ b/src/librssguard/services/standard/gui/formdiscoverfeeds.h
@@ -19,18 +19,25 @@ class DiscoveredFeedsModel : public QAbstractListModel {
     Q_OBJECT
 
   public:
+    struct FeedItem {
+        bool m_isChecked;
+        StandardFeed* m_feed;
+    };
+
     explicit DiscoveredFeedsModel(QObject* parent = {});
 
     virtual QVariant headerData(int section, Qt::Orientation orientation, int role) const;
     virtual int rowCount(const QModelIndex& parent) const;
     virtual int columnCount(const QModelIndex& parent) const;
     virtual QVariant data(const QModelIndex& index, int role) const;
+    virtual bool setData(const QModelIndex& index, const QVariant& value, int role);
+    virtual Qt::ItemFlags flags(const QModelIndex& index) const;
 
-    QList<StandardFeed*> discoveredFeeds() const;
-    void setDiscoveredFeeds(const QList<StandardFeed*>& newDiscoveredFeeds);
+    QList<FeedItem> discoveredFeeds() const;
+    void setDiscoveredFeeds(const QList<StandardFeed*>& feeds);
 
   private:
-    QList<StandardFeed*> m_discoveredFeeds;
+    QList<FeedItem> m_discoveredFeeds;
 };
 
 class FormDiscoverFeeds : public QDialog {
@@ -50,12 +57,14 @@ class FormDiscoverFeeds : public QDialog {
     void importSelectedFeeds();
 
   private:
+    void userWantsAdvanced();
     void loadDiscoveredFeeds(const QList<StandardFeed*>& feeds);
     void loadCategories(const QList<Category*>& categories, RootItem* root_item);
 
   private:
     Ui::FormDiscoverFeeds m_ui;
     QPushButton* m_btnImportSelectedFeeds;
+    QPushButton* m_btnGoAdvanced;
     ServiceRoot* m_serviceRoot;
     QList<FeedParser*> m_parsers;
     QFutureWatcher<QList<StandardFeed*>> m_watcherLookup;
diff --git a/src/librssguard/services/standard/gui/formdiscoverfeeds.ui b/src/librssguard/services/standard/gui/formdiscoverfeeds.ui
index 4d4e3f278..358fe774e 100644
--- a/src/librssguard/services/standard/gui/formdiscoverfeeds.ui
+++ b/src/librssguard/services/standard/gui/formdiscoverfeeds.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>406</width>
-    <height>334</height>
+    <width>513</width>
+    <height>360</height>
    </rect>
   </property>
   <property name="windowTitle">
diff --git a/src/librssguard/services/standard/parsers/atomparser.cpp b/src/librssguard/services/standard/parsers/atomparser.cpp
index e77602393..474709524 100644
--- a/src/librssguard/services/standard/parsers/atomparser.cpp
+++ b/src/librssguard/services/standard/parsers/atomparser.cpp
@@ -4,6 +4,8 @@
 
 #include "definitions/definitions.h"
 #include "exceptions/applicationexception.h"
+#include "miscellaneous/application.h"
+#include "miscellaneous/settings.h"
 #include "miscellaneous/textfactory.h"
 #include "services/standard/definitions.h"
 #include "services/standard/standardfeed.h"
@@ -24,7 +26,178 @@ AtomParser::AtomParser(const QString& data) : FeedParser(data) {
 AtomParser::~AtomParser() {}
 
 QList<StandardFeed*> AtomParser::discoverFeeds(ServiceRoot* root, const QUrl& url) const {
-  return {};
+  QString my_url = url.toString();
+  QList<StandardFeed*> feeds;
+
+  // 1. Test direct URL for a feed.
+  // 2. Test embedded ATOM feed links from HTML data.
+  // 3. Test "URL/feed" endpoint.
+  // 4. Test "URL/atom" endpoint.
+  // 5. If URL is Github repository, test for:
+  //    https://github.com/:owner/:repo/releases.atom
+  //    https://github.com/:owner/:repo/commits.atom
+  //    https://github.com/:user/:repo/tags.atom
+
+  // Download URL.
+  int timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();
+  QByteArray data;
+  auto res = NetworkFactory::performNetworkOperation(my_url,
+                                                     timeout,
+                                                     {},
+                                                     data,
+                                                     QNetworkAccessManager::Operation::GetOperation,
+                                                     {},
+                                                     {},
+                                                     {},
+                                                     {},
+                                                     root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      // 1.
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+
+      return {guessed_feed.first};
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+
+    // 2.
+    QRegularExpression rx(QSL(ATOM_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+    QRegularExpression rx_href(QSL(ATOM_HREF_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+
+    rx_href.optimize();
+
+    QRegularExpressionMatchIterator it_rx = rx.globalMatch(QString::fromUtf8(data));
+
+    while (it_rx.hasNext()) {
+      QRegularExpressionMatch mat_tx = it_rx.next();
+      QString link_tag = mat_tx.captured();
+      QString feed_link = rx_href.match(link_tag).captured(1);
+
+      if (feed_link.startsWith(QL1S("//"))) {
+        feed_link = QSL(URI_SCHEME_HTTP) + feed_link.mid(2);
+      }
+      else if (feed_link.startsWith(QL1C('/'))) {
+        feed_link = url.toString(QUrl::UrlFormattingOption::RemovePath | QUrl::UrlFormattingOption::RemoveQuery |
+                                 QUrl::UrlFormattingOption::StripTrailingSlash) +
+                    feed_link;
+      }
+
+      QByteArray data;
+      auto res = NetworkFactory::performNetworkOperation(feed_link,
+                                                         timeout,
+                                                         {},
+                                                         data,
+                                                         QNetworkAccessManager::Operation::GetOperation,
+                                                         {},
+                                                         {},
+                                                         {},
+                                                         {},
+                                                         root->networkProxy());
+
+      if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+        try {
+          auto guessed_feed = guessFeed(data, res.m_contentType);
+
+          guessed_feed.first->setSource(feed_link);
+          feeds.append(guessed_feed.first);
+        }
+        catch (const ApplicationException& ex) {
+          qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(feed_link)
+                   << " should be direct link to feed file but was not recognized:" << QUOTE_W_SPACE_DOT(ex.message());
+        }
+      }
+    }
+  }
+
+  // 3.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QSL("/feed");
+  res = NetworkFactory::performNetworkOperation(my_url,
+                                                timeout,
+                                                {},
+                                                data,
+                                                QNetworkAccessManager::Operation::GetOperation,
+                                                {},
+                                                {},
+                                                {},
+                                                {},
+                                                root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+      feeds.append(guessed_feed.first);
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+  }
+
+  // 4.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QSL("/atom");
+  res = NetworkFactory::performNetworkOperation(my_url,
+                                                timeout,
+                                                {},
+                                                data,
+                                                QNetworkAccessManager::Operation::GetOperation,
+                                                {},
+                                                {},
+                                                {},
+                                                {},
+                                                root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+      feeds.append(guessed_feed.first);
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+  }
+
+  // 5.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash);
+
+  if (QRegularExpression(QSL(GITHUB_URL_REGEX)).match(my_url).isValid()) {
+    QStringList github_feeds = {QSL("releases.atom"), QSL("commits.atom"), QSL("tags.atom")};
+
+    for (const QString& github_feed : github_feeds) {
+      my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QL1C('/') + github_feed;
+      res = NetworkFactory::performNetworkOperation(my_url,
+                                                    timeout,
+                                                    {},
+                                                    data,
+                                                    QNetworkAccessManager::Operation::GetOperation,
+                                                    {},
+                                                    {},
+                                                    {},
+                                                    {},
+                                                    root->networkProxy());
+
+      if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+        try {
+          auto guessed_feed = guessFeed(data, res.m_contentType);
+
+          guessed_feed.first->setSource(my_url);
+          feeds.append(guessed_feed.first);
+        }
+        catch (...) {
+          qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+        }
+      }
+    }
+  }
+
+  return feeds;
 }
 
 QPair<StandardFeed*, QList<IconLocation>> AtomParser::guessFeed(const QByteArray& content,
diff --git a/src/librssguard/services/standard/parsers/jsonparser.cpp b/src/librssguard/services/standard/parsers/jsonparser.cpp
index 539c0ec6c..08df7c872 100644
--- a/src/librssguard/services/standard/parsers/jsonparser.cpp
+++ b/src/librssguard/services/standard/parsers/jsonparser.cpp
@@ -6,6 +6,7 @@
 #include "definitions/typedefs.h"
 #include "exceptions/applicationexception.h"
 #include "exceptions/feedrecognizedbutfailedexception.h"
+#include "miscellaneous/settings.h"
 #include "miscellaneous/textfactory.h"
 #include "services/standard/definitions.h"
 #include "services/standard/standardfeed.h"
@@ -19,7 +20,89 @@ JsonParser::JsonParser(const QString& data) : FeedParser(data, false) {}
 JsonParser::~JsonParser() {}
 
 QList<StandardFeed*> JsonParser::discoverFeeds(ServiceRoot* root, const QUrl& url) const {
-  return {};
+  QString my_url = url.toString();
+  QList<StandardFeed*> feeds;
+
+  // 1. Test direct URL for a feed.
+  // 2. Test embedded JSON feed links from HTML data.
+
+  // Download URL.
+  int timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();
+  QByteArray data;
+  auto res = NetworkFactory::performNetworkOperation(my_url,
+                                                     timeout,
+                                                     {},
+                                                     data,
+                                                     QNetworkAccessManager::Operation::GetOperation,
+                                                     {},
+                                                     {},
+                                                     {},
+                                                     {},
+                                                     root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      // 1.
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+
+      return {guessed_feed.first};
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+
+    // 2.
+    QRegularExpression rx(QSL(JSON_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+    QRegularExpression rx_href(QSL(JSON_HREF_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+
+    rx_href.optimize();
+
+    QRegularExpressionMatchIterator it_rx = rx.globalMatch(QString::fromUtf8(data));
+
+    while (it_rx.hasNext()) {
+      QRegularExpressionMatch mat_tx = it_rx.next();
+      QString link_tag = mat_tx.captured();
+      QString feed_link = rx_href.match(link_tag).captured(1);
+
+      if (feed_link.startsWith(QL1S("//"))) {
+        feed_link = QSL(URI_SCHEME_HTTP) + feed_link.mid(2);
+      }
+      else if (feed_link.startsWith(QL1C('/'))) {
+        feed_link = url.toString(QUrl::UrlFormattingOption::RemovePath | QUrl::UrlFormattingOption::RemoveQuery |
+                                 QUrl::UrlFormattingOption::StripTrailingSlash) +
+                    feed_link;
+      }
+
+      QByteArray data;
+      auto res = NetworkFactory::performNetworkOperation(feed_link,
+                                                         timeout,
+                                                         {},
+                                                         data,
+                                                         QNetworkAccessManager::Operation::GetOperation,
+                                                         {},
+                                                         {},
+                                                         {},
+                                                         {},
+                                                         root->networkProxy());
+
+      if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+        try {
+          auto guessed_feed = guessFeed(data, res.m_contentType);
+
+          guessed_feed.first->setSource(feed_link);
+          feeds.append(guessed_feed.first);
+        }
+        catch (const ApplicationException& ex) {
+          qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(feed_link)
+                   << " should be direct link to feed file but was not recognized:" << QUOTE_W_SPACE_DOT(ex.message());
+        }
+      }
+    }
+  }
+
+  return feeds;
 }
 
 QPair<StandardFeed*, QList<IconLocation>> JsonParser::guessFeed(const QByteArray& content,
diff --git a/src/librssguard/services/standard/parsers/rdfparser.cpp b/src/librssguard/services/standard/parsers/rdfparser.cpp
index 1adcd9c3a..7a475b65a 100644
--- a/src/librssguard/services/standard/parsers/rdfparser.cpp
+++ b/src/librssguard/services/standard/parsers/rdfparser.cpp
@@ -3,6 +3,7 @@
 #include "services/standard/parsers/rdfparser.h"
 
 #include "exceptions/applicationexception.h"
+#include "miscellaneous/settings.h"
 #include "miscellaneous/textfactory.h"
 #include "services/standard/definitions.h"
 #include "services/standard/standardfeed.h"
@@ -18,7 +19,141 @@ RdfParser::RdfParser(const QString& data)
 RdfParser::~RdfParser() {}
 
 QList<StandardFeed*> RdfParser::discoverFeeds(ServiceRoot* root, const QUrl& url) const {
-  return {};
+  QString my_url = url.toString();
+  QList<StandardFeed*> feeds;
+
+  // 1. Test direct URL for a feed.
+  // 2. Test embedded RDF feed links from HTML data.
+  // 3. Test "URL/feed" endpoint.
+  // 4. Test "URL/rdf" endpoint.
+
+  // Download URL.
+  int timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();
+  QByteArray data;
+  auto res = NetworkFactory::performNetworkOperation(my_url,
+                                                     timeout,
+                                                     {},
+                                                     data,
+                                                     QNetworkAccessManager::Operation::GetOperation,
+                                                     {},
+                                                     {},
+                                                     {},
+                                                     {},
+                                                     root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      // 1.
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+
+      return {guessed_feed.first};
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+
+    // 2.
+    QRegularExpression rx(QSL(RSS_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+    QRegularExpression rx_href(QSL(RSS_HREF_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+
+    rx_href.optimize();
+
+    QRegularExpressionMatchIterator it_rx = rx.globalMatch(QString::fromUtf8(data));
+
+    while (it_rx.hasNext()) {
+      QRegularExpressionMatch mat_tx = it_rx.next();
+      QString link_tag = mat_tx.captured();
+      QString feed_link = rx_href.match(link_tag).captured(1);
+
+      if (feed_link.startsWith(QL1S("//"))) {
+        feed_link = QSL(URI_SCHEME_HTTP) + feed_link.mid(2);
+      }
+      else if (feed_link.startsWith(QL1C('/'))) {
+        feed_link = url.toString(QUrl::UrlFormattingOption::RemovePath | QUrl::UrlFormattingOption::RemoveQuery |
+                                 QUrl::UrlFormattingOption::StripTrailingSlash) +
+                    feed_link;
+      }
+
+      QByteArray data;
+      auto res = NetworkFactory::performNetworkOperation(feed_link,
+                                                         timeout,
+                                                         {},
+                                                         data,
+                                                         QNetworkAccessManager::Operation::GetOperation,
+                                                         {},
+                                                         {},
+                                                         {},
+                                                         {},
+                                                         root->networkProxy());
+
+      if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+        try {
+          auto guessed_feed = guessFeed(data, res.m_contentType);
+
+          guessed_feed.first->setSource(feed_link);
+          feeds.append(guessed_feed.first);
+        }
+        catch (const ApplicationException& ex) {
+          qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(feed_link)
+                   << " should be direct link to feed file but was not recognized:" << QUOTE_W_SPACE_DOT(ex.message());
+        }
+      }
+    }
+  }
+
+  // 3.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QSL("/feed");
+  res = NetworkFactory::performNetworkOperation(my_url,
+                                                timeout,
+                                                {},
+                                                data,
+                                                QNetworkAccessManager::Operation::GetOperation,
+                                                {},
+                                                {},
+                                                {},
+                                                {},
+                                                root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+      feeds.append(guessed_feed.first);
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+  }
+
+  // 4.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QSL("/rdf");
+  res = NetworkFactory::performNetworkOperation(my_url,
+                                                timeout,
+                                                {},
+                                                data,
+                                                QNetworkAccessManager::Operation::GetOperation,
+                                                {},
+                                                {},
+                                                {},
+                                                {},
+                                                root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+      feeds.append(guessed_feed.first);
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+  }
+
+  return feeds;
 }
 
 QPair<StandardFeed*, QList<IconLocation>> RdfParser::guessFeed(const QByteArray& content,
diff --git a/src/librssguard/services/standard/parsers/rssparser.cpp b/src/librssguard/services/standard/parsers/rssparser.cpp
index faa2f7aba..8bfce44e8 100644
--- a/src/librssguard/services/standard/parsers/rssparser.cpp
+++ b/src/librssguard/services/standard/parsers/rssparser.cpp
@@ -19,12 +19,18 @@ RssParser::RssParser(const QString& data) : FeedParser(data) {}
 RssParser::~RssParser() {}
 
 QList<StandardFeed*> RssParser::discoverFeeds(ServiceRoot* root, const QUrl& url) const {
+  QString my_url = url.toString();
   QList<StandardFeed*> feeds;
 
+  // 1. Test direct URL for a feed.
+  // 2. Test embedded RSS feed links from HTML data.
+  // 3. Test "URL/feed" endpoint.
+  // 4. Test "URL/rss" endpoint.
+
   // Download URL.
   int timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();
   QByteArray data;
-  auto res = NetworkFactory::performNetworkOperation(url.toString(),
+  auto res = NetworkFactory::performNetworkOperation(my_url,
                                                      timeout,
                                                      {},
                                                      data,
@@ -36,20 +42,21 @@ QList<StandardFeed*> RssParser::discoverFeeds(ServiceRoot* root, const QUrl& url
                                                      root->networkProxy());
 
   if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
-    // Parse result, might be HTML or directly the feed file.
     try {
+      // 1.
       auto guessed_feed = guessFeed(data, res.m_contentType);
 
-      guessed_feed.first->setSource(url.toString());
+      guessed_feed.first->setSource(my_url);
 
       return {guessed_feed.first};
     }
     catch (...) {
-      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(url) << "is not a direct feed file.";
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
     }
 
-    QRegularExpression rx(QSL(FEED_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
-    QRegularExpression rx_href(QSL(FEED_HREF_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+    // 2.
+    QRegularExpression rx(QSL(RSS_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
+    QRegularExpression rx_href(QSL(RSS_HREF_REGEX_MATCHER), QRegularExpression::PatternOption::CaseInsensitiveOption);
 
     rx_href.optimize();
 
@@ -82,22 +89,70 @@ QList<StandardFeed*> RssParser::discoverFeeds(ServiceRoot* root, const QUrl& url
                                                          root->networkProxy());
 
       if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
-        // Parse result, might be HTML or directly the feed file.
         try {
           auto guessed_feed = guessFeed(data, res.m_contentType);
 
-          guessed_feed.first->setSource(url.toString());
-
+          guessed_feed.first->setSource(feed_link);
           feeds.append(guessed_feed.first);
         }
         catch (const ApplicationException& ex) {
-          qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(url)
+          qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(feed_link)
                    << " should be direct link to feed file but was not recognized:" << QUOTE_W_SPACE_DOT(ex.message());
         }
       }
     }
   }
 
+  // 3.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QSL("/feed");
+  res = NetworkFactory::performNetworkOperation(my_url,
+                                                timeout,
+                                                {},
+                                                data,
+                                                QNetworkAccessManager::Operation::GetOperation,
+                                                {},
+                                                {},
+                                                {},
+                                                {},
+                                                root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+      feeds.append(guessed_feed.first);
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+  }
+
+  // 4.
+  my_url = url.toString(QUrl::UrlFormattingOption::StripTrailingSlash) + QSL("/rss");
+  res = NetworkFactory::performNetworkOperation(my_url,
+                                                timeout,
+                                                {},
+                                                data,
+                                                QNetworkAccessManager::Operation::GetOperation,
+                                                {},
+                                                {},
+                                                {},
+                                                {},
+                                                root->networkProxy());
+
+  if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+    try {
+      auto guessed_feed = guessFeed(data, res.m_contentType);
+
+      guessed_feed.first->setSource(my_url);
+      feeds.append(guessed_feed.first);
+    }
+    catch (...) {
+      qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct feed file.";
+    }
+  }
+
   return feeds;
 }
 
diff --git a/src/librssguard/services/standard/parsers/sitemapparser.cpp b/src/librssguard/services/standard/parsers/sitemapparser.cpp
index 79dbdd3de..4d3ec78b8 100644
--- a/src/librssguard/services/standard/parsers/sitemapparser.cpp
+++ b/src/librssguard/services/standard/parsers/sitemapparser.cpp
@@ -9,6 +9,7 @@
 #include "definitions/definitions.h"
 #include "exceptions/applicationexception.h"
 #include "exceptions/feedrecognizedbutfailedexception.h"
+#include "miscellaneous/settings.h"
 #include "miscellaneous/textfactory.h"
 #include "services/standard/definitions.h"
 
@@ -21,7 +22,108 @@ SitemapParser::SitemapParser(const QString& data) : FeedParser(data) {}
 SitemapParser::~SitemapParser() {}
 
 QList<StandardFeed*> SitemapParser::discoverFeeds(ServiceRoot* root, const QUrl& url) const {
-  return {};
+  QHash<QString, StandardFeed*> feeds;
+  QStringList to_process_sitemaps;
+
+  // 1. Process "URL/robots.txt" file.
+  // 2. Process "URLHOST/robots.txt" file.
+  // 3. Direct URL test. If sitemap index, process its children.
+  // 4. Test "URL/sitemap.xml" endpoint.
+  // 5. Test "URL/sitemap.xml.gz" endpoint.
+
+  // 1.
+  // 2.
+  QStringList to_process_robots = {
+    url.toString(QUrl::UrlFormattingOption::StripTrailingSlash).replace(QRegularExpression(QSL("\\/$")), QString()) +
+      QSL("/robots.txt"),
+    url.toString(QUrl::UrlFormattingOption::RemovePath | QUrl::UrlFormattingOption::RemoveQuery) + QSL("/robots.txt")};
+
+  to_process_robots.removeDuplicates();
+
+  for (const QString& robots_url : to_process_robots) {
+    // Download URL.
+    int timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();
+    QByteArray data;
+    auto res = NetworkFactory::performNetworkOperation(robots_url,
+                                                       timeout,
+                                                       {},
+                                                       data,
+                                                       QNetworkAccessManager::Operation::GetOperation,
+                                                       {},
+                                                       {},
+                                                       {},
+                                                       {},
+                                                       root->networkProxy());
+
+    if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+      QRegularExpression rx(QSL("Sitemap: ?([^\\r\\n]+)"),
+                            QRegularExpression::PatternOption::CaseInsensitiveOption |
+                              QRegularExpression::PatternOption::MultilineOption);
+      QRegularExpressionMatchIterator it_rx = rx.globalMatch(QString::fromUtf8(data));
+
+      while (it_rx.hasNext()) {
+        QString sitemap_link = it_rx.next().captured(1);
+
+        to_process_sitemaps.append(sitemap_link);
+      }
+    }
+  }
+
+  // 3.
+  to_process_sitemaps.append(url.toString());
+
+  // 4.
+  to_process_sitemaps.append(url.toString(QUrl::UrlFormattingOption::StripTrailingSlash)
+                               .replace(QRegularExpression(QSL("\\/$")), QString()) +
+                             QSL("/sitemap.xml"));
+
+  // 5.
+  to_process_sitemaps.append(url.toString(QUrl::UrlFormattingOption::StripTrailingSlash)
+                               .replace(QRegularExpression(QSL("\\/$")), QString()) +
+                             QSL("/sitemap.xml.gz"));
+
+  while (!to_process_sitemaps.isEmpty()) {
+    to_process_sitemaps.removeDuplicates();
+
+    QString my_url = to_process_sitemaps.takeFirst();
+
+    if (feeds.contains(my_url)) {
+      continue;
+    }
+
+    // Download URL.
+    int timeout = qApp->settings()->value(GROUP(Feeds), SETTING(Feeds::UpdateTimeout)).toInt();
+    QByteArray data;
+    auto res = NetworkFactory::performNetworkOperation(my_url,
+                                                       timeout,
+                                                       {},
+                                                       data,
+                                                       QNetworkAccessManager::Operation::GetOperation,
+                                                       {},
+                                                       {},
+                                                       {},
+                                                       {},
+                                                       root->networkProxy());
+
+    if (res.m_networkError == QNetworkReply::NetworkError::NoError) {
+      try {
+        // 1.
+        auto guessed_feed = guessFeed(data, res.m_contentType);
+
+        guessed_feed.first->setSource(my_url);
+        feeds.insert(my_url, guessed_feed.first);
+      }
+      catch (const FeedRecognizedButFailedException& ex) {
+        // This is index.
+        to_process_sitemaps.append(ex.arbitraryData().toStringList());
+      }
+      catch (const ApplicationException&) {
+        qDebugNN << LOGSEC_CORE << QUOTE_W_SPACE(my_url) << "is not a direct sitemap file.";
+      }
+    }
+  }
+
+  return feeds.values();
 }
 
 QPair<StandardFeed*, QList<IconLocation>> SitemapParser::guessFeed(const QByteArray& content,
@@ -73,7 +175,14 @@ QPair<StandardFeed*, QList<IconLocation>> SitemapParser::guessFeed(const QByteAr
   QDomElement root_element = xml_document.documentElement();
 
   if (root_element.tagName() == QSL("sitemapindex")) {
-    throw FeedRecognizedButFailedException(QObject::tr("sitemap indices are not supported"));
+    QStringList locs;
+    int i = 0;
+
+    for (QDomNodeList ndl = root_element.elementsByTagNameNS(sitemapNamespace(), QSL("loc")); i < ndl.size(); i++) {
+      locs << ndl.at(i).toElement().text();
+    }
+
+    throw FeedRecognizedButFailedException(QObject::tr("sitemap indices are not supported"), locs);
   }
 
   if (root_element.tagName() != QSL("urlset")) {
@@ -180,5 +289,5 @@ QList<Enclosure> SitemapParser::xmlMessageEnclosures(const QDomElement& msg_elem
 }
 
 bool SitemapParser::isGzip(const QByteArray& content) {
-  return ((content[0] & 0xFF) == 0x1f) && ((content[1] & 0xFF) == 0x8b);
+  return content.size() >= 2 && ((content[0] & 0xFF) == 0x1f) && ((content[1] & 0xFF) == 0x8b);
 }
diff --git a/src/librssguard/services/standard/standardserviceroot.cpp b/src/librssguard/services/standard/standardserviceroot.cpp
index c1754d2f2..22e8bc855 100644
--- a/src/librssguard/services/standard/standardserviceroot.cpp
+++ b/src/librssguard/services/standard/standardserviceroot.cpp
@@ -140,16 +140,14 @@ void StandardServiceRoot::addNewFeed(RootItem* selected_item, const QString& url
                                                                         url,
                                                                         qApp->mainFormWidget()));
 
-  form_discover->exec();
+  if (form_discover->exec() == ADVANCED_FEED_ADD_DIALOG_CODE) {
+    QScopedPointer<FormStandardFeedDetails> form_pointer(new FormStandardFeedDetails(this,
+                                                                                     selected_item,
+                                                                                     url,
+                                                                                     qApp->mainFormWidget()));
 
-  /*
-  QScopedPointer<FormStandardFeedDetails> form_pointer(new FormStandardFeedDetails(this,
-                                                                                   selected_item,
-                                                                                   url,
-                                                                                   qApp->mainFormWidget()));
-
-  form_pointer->addEditFeed<StandardFeed>();
-  */
+    form_pointer->addEditFeed<StandardFeed>();
+  }
 
   qApp->feedUpdateLock()->unlock();
 }
diff --git a/src/librssguard/services/standard/standardserviceroot.h b/src/librssguard/services/standard/standardserviceroot.h
index 35e03868b..be9a8f2a6 100644
--- a/src/librssguard/services/standard/standardserviceroot.h
+++ b/src/librssguard/services/standard/standardserviceroot.h
@@ -15,10 +15,10 @@ class FeedsImportExportModel;
 class QMenu;
 
 class StandardServiceRoot : public ServiceRoot {
-  Q_OBJECT
+    Q_OBJECT
 
-  friend class FormStandardFeedDetails;
-  friend class FormStandardImportExport;
+    friend class FormStandardFeedDetails;
+    friend class FormStandardImportExport;
 
   public:
     explicit StandardServiceRoot(RootItem* parent = nullptr);
@@ -48,7 +48,6 @@ class StandardServiceRoot : public ServiceRoot {
     void exportFeeds();
 
   private:
-
     // Takes structure residing under given root item and adds feeds/categories from
     // it to active structure.
     // NOTE: This is used for import/export of the model.