diff --git a/imageviewwidget.cpp b/imageviewwidget.cpp
index 98b3538..ef7238c 100644
--- a/imageviewwidget.cpp
+++ b/imageviewwidget.cpp
@@ -3,6 +3,7 @@
 #include <QPainter>
 #include <QKeyEvent>
 #include <QImageReader>
+#include <algorithm>
 
 ImageViewWidget::ImageViewWidget(QWidget *parent)
     : QWidget(parent)
@@ -22,6 +23,8 @@ void ImageViewWidget::setImage(const QString &path)
     else
         m_pixmap = QPixmap();
 
+    m_zoomMode = FitToScreen;
+    m_zoomFactor = 1.0;
     update();
 }
 
@@ -31,10 +34,26 @@ void ImageViewWidget::paintEvent(QPaintEvent *)
         return;
 
     QPainter painter(this);
-    QPixmap scaled = m_pixmap.scaled(size(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
-    int x = (width()  - scaled.width())  / 2;
-    int y = (height() - scaled.height()) / 2;
-    painter.drawPixmap(x, y, scaled);
+    QPixmap drawn;
+
+    switch (m_zoomMode) {
+    case FitToScreen:
+        drawn = m_pixmap.scaled(size(), Qt::KeepAspectRatio, Qt::SmoothTransformation);
+        break;
+    case OriginalSize:
+        drawn = m_pixmap;
+        break;
+    case CustomZoom: {
+        QSize target(static_cast<int>(m_pixmap.width() * m_zoomFactor),
+                     static_cast<int>(m_pixmap.height() * m_zoomFactor));
+        drawn = m_pixmap.scaled(target, Qt::KeepAspectRatio, Qt::SmoothTransformation);
+        break;
+    }
+    }
+
+    int x = (width()  - drawn.width())  / 2;
+    int y = (height() - drawn.height()) / 2;
+    painter.drawPixmap(x, y, drawn);
 }
 
 void ImageViewWidget::keyPressEvent(QKeyEvent *event)
@@ -60,5 +79,73 @@ void ImageViewWidget::keyPressEvent(QKeyEvent *event)
         return;
     }
 
+    if (event->key() == Qt::Key_Slash)
+    {
+        zoomOriginal();
+        event->accept();
+        return;
+    }
+
+    if (event->key() == Qt::Key_Asterisk)
+    {
+        zoomFitToScreen();
+        event->accept();
+        return;
+    }
+
+    if (event->key() == Qt::Key_Plus)
+    {
+        zoomIn();
+        event->accept();
+        return;
+    }
+
+    if (event->key() == Qt::Key_Minus)
+    {
+        zoomOut();
+        event->accept();
+        return;
+    }
+
     QWidget::keyPressEvent(event);
 }
+
+void ImageViewWidget::zoomIn()
+{
+    if (m_zoomMode == FitToScreen) {
+        // Calculate the current effective scale so zooming feels continuous
+        double sx = static_cast<double>(width()) / m_pixmap.width();
+        double sy = static_cast<double>(height()) / m_pixmap.height();
+        m_zoomFactor = std::min(sx, sy);
+    }
+    m_zoomFactor *= 1.25;
+    m_zoomMode = CustomZoom;
+    update();
+}
+
+void ImageViewWidget::zoomOut()
+{
+    if (m_zoomMode == FitToScreen) {
+        double sx = static_cast<double>(width()) / m_pixmap.width();
+        double sy = static_cast<double>(height()) / m_pixmap.height();
+        m_zoomFactor = std::min(sx, sy);
+    }
+    m_zoomFactor /= 1.25;
+    if (m_zoomFactor < 0.01)
+        m_zoomFactor = 0.01;
+    m_zoomMode = CustomZoom;
+    update();
+}
+
+void ImageViewWidget::zoomOriginal()
+{
+    m_zoomMode = OriginalSize;
+    m_zoomFactor = 1.0;
+    update();
+}
+
+void ImageViewWidget::zoomFitToScreen()
+{
+    m_zoomMode = FitToScreen;
+    update();
+}
diff --git a/imageviewwidget.h b/imageviewwidget.h
index c6f5d3c..af2935a 100644
--- a/imageviewwidget.h
+++ b/imageviewwidget.h
@@ -10,9 +10,15 @@ class ImageViewWidget : public QWidget
     Q_OBJECT
 
 public:
+    enum ZoomMode { FitToScreen, OriginalSize, CustomZoom };
+
     explicit ImageViewWidget(QWidget *parent = nullptr);
 
     void setImage(const QString &path);
+    void zoomIn();
+    void zoomOut();
+    void zoomOriginal();
+    void zoomFitToScreen();
 
 signals:
     void closeRequested();
@@ -25,4 +31,6 @@ protected:
 
 private:
     QPixmap m_pixmap;
+    ZoomMode m_zoomMode = FitToScreen;
+    double m_zoomFactor = 1.0;
 };