diff --git a/inc/graph/server/gui/mainwindow.h b/inc/graph/server/gui/mainwindow.h
index b85b88c..1272037 100644
--- a/inc/graph/server/gui/mainwindow.h
+++ b/inc/graph/server/gui/mainwindow.h
@@ -2,10 +2,12 @@
 
 #include <graph/server/gui/chart/chart.h>
 #include <graph/server/plugin.h>
+#include <qfiledialog.h>
 #include <QMainWindow>
 #include <QMenuBar>
 #include <QStatusBar>
 #include <QToolBar>
+#include <cstddef>
 #include <vector>
 
 namespace Ui {
@@ -33,9 +35,12 @@ class MainWindow : public QMainWindow {
   void on_action_Load_triggered();
 
  private:
+  static MainWindow* instance;
   Ui::MainWindow* ui;
 
   PluginModel* pluginModel;
   std::vector<ChartWidget*> charts;
+
+  QFileDialog* fileDialog;
 };
 } // namespace Graph::GUI
diff --git a/inc/graph/server/gui/specdialog/specdialog.h b/inc/graph/server/gui/specdialog/specdialog.h
index a1d2bbd..c2bbea3 100644
--- a/inc/graph/server/gui/specdialog/specdialog.h
+++ b/inc/graph/server/gui/specdialog/specdialog.h
@@ -11,14 +11,22 @@ class SpecDialog;
 namespace Graph::GUI {
 class SpecDialog : public QDialog {
   Q_OBJECT
- public:
+ private:
   explicit SpecDialog(QWidget* parent = nullptr);
+
+ public:
+  SpecDialog(SpecDialog& other) = delete;
+  void operator=(const SpecDialog&) = delete;
   ~SpecDialog();
 
+  static SpecDialog* getInstance();
+  static void close();
+
   QStringList getList() const { return series->stringList(); }
   chart_spec_t getSpec() const;
 
  private:
+  static SpecDialog* instance;
   Ui::SpecDialog* ui;
 
   QStringListModel* series;
diff --git a/src/graph/server/gui/mainwindow.cpp b/src/graph/server/gui/mainwindow.cpp
index 6d6700f..c6659f2 100644
--- a/src/graph/server/gui/mainwindow.cpp
+++ b/src/graph/server/gui/mainwindow.cpp
@@ -4,6 +4,7 @@
 #include <graph/server/plugin.h>
 #include <graph/server/spec.h>
 #include <graph/server/ui_mainwindow.h>
+#include <qfiledialog.h>
 #include <QFileDialog>
 #include <QMessageBox>
 #include <iostream>
@@ -13,7 +14,8 @@
 #define MAX(a, b) (a > b ? a : b)
 
 namespace Graph::GUI {
-MainWindow* instance = nullptr;
+
+MainWindow* MainWindow::instance = nullptr;
 
 MainWindow* MainWindow::getInstance() {
   if (!instance)
@@ -23,6 +25,7 @@ MainWindow* MainWindow::getInstance() {
 }
 
 void MainWindow::close() {
+  SpecDialog::close();
   if (instance)
     delete instance;
 }
@@ -82,6 +85,8 @@ MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent), ui(new Ui::MainWi
       ui->pluginsListView->doItemsLayout();
     }
   });
+
+  fileDialog = new QFileDialog(this, "Load plugin", "./plugins", "Plugin (*.so *.dll *.dlsym)");
 }
 
 MainWindow::~MainWindow() {
@@ -90,21 +95,22 @@ MainWindow::~MainWindow() {
   }
 
   delete pluginModel;
+  delete fileDialog;
 }
 
 void MainWindow::on_action_Add_triggered() {
-  SpecDialog dialog;
-  if (dialog.exec() == SpecDialog::Rejected)
+  SpecDialog* dialog = SpecDialog::getInstance();
+  if (dialog->exec() == SpecDialog::Rejected)
     return;
 
-  ChartWidget* chart = new ChartWidget(ui->graphsListWidget, dialog.getSpec());
+  ChartWidget* chart = new ChartWidget(ui->graphsListWidget, dialog->getSpec());
 
   charts.push_back(chart);
 
   ui->graphsListWidget->addItem(chart);
   ui->graphsListWidget->setItemWidget(chart, chart->getView());
 
-  for (QString title : dialog.getList()) {
+  for (QString title : dialog->getList()) {
     QLineSeries* series = new QLineSeries();
     series->setName(title);
     chart->getChart()->addSeries(series);
@@ -115,25 +121,25 @@ void MainWindow::on_action_Add_triggered() {
 }
 
 void MainWindow::on_action_Load_triggered() {
-  QString file = QFileDialog::getOpenFileName(this, "Load plugin", ".", "Plugins (*.so *.dll *.dylib)");
-
-  if (file.isEmpty())
+  if (!fileDialog->exec())
     return;
 
-  try {
-    Plugin* plugin = new Plugin(file.toStdString());
-    plugin->init(&Graph::GUI::addData);
-    pluginModel->add(plugin);
-  } catch (std::runtime_error e) {
-    std::cout << e.what() << std::endl;
-    QMessageBox::critical(this, "Error", "Failed to load plugin.", QMessageBox::StandardButton::Ignore);
-  }
+  for (QString file : fileDialog->selectedFiles()) {
+    try {
+      Plugin* plugin = new Plugin(file.toStdString());
+      plugin->init(&Graph::GUI::addData);
+      pluginModel->add(plugin);
+    } catch (std::runtime_error e) {
+      std::cout << e.what() << std::endl;
+      QMessageBox::critical(this, "Error", "Failed to load plugin:\n" + file, QMessageBox::StandardButton::Ignore);
+    }
 
-  int row = pluginModel->rowCount();
-  pluginModel->insertRow(row);
-  QModelIndex index = pluginModel->index(row);
-  ui->pluginsListView->doItemsLayout();
-  ui->pluginsListView->setCurrentIndex(index);
+    int row = pluginModel->rowCount();
+    pluginModel->insertRow(row);
+    QModelIndex index = pluginModel->index(row);
+    ui->pluginsListView->doItemsLayout();
+    ui->pluginsListView->setCurrentIndex(index);
+  }
 }
 
 } // namespace Graph::GUI
diff --git a/src/graph/server/gui/specdialog/specdialog.cpp b/src/graph/server/gui/specdialog/specdialog.cpp
index f065d3e..92f8ce1 100644
--- a/src/graph/server/gui/specdialog/specdialog.cpp
+++ b/src/graph/server/gui/specdialog/specdialog.cpp
@@ -3,6 +3,20 @@
 #include <graph/server/ui_specdialog.h>
 
 namespace Graph::GUI {
+SpecDialog* SpecDialog::instance = nullptr;
+
+SpecDialog* SpecDialog::getInstance() {
+  if (!instance)
+    instance = new SpecDialog();
+
+  return instance;
+}
+
+void SpecDialog::close() {
+  if(instance)
+    delete instance;
+}
+
 SpecDialog::SpecDialog(QWidget* parent) : QDialog(parent), ui(new Ui::SpecDialog) {
   ui->setupUi(this);