diff --git a/CMakeLists.txt b/CMakeLists.txt
index ea1e767..3eba63e 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -12,6 +12,8 @@ qt_add_executable(ImageBrowser
     mainwindow.h
     imagemodel.cpp
     imagemodel.h
+    thumbnailworker.cpp
+    thumbnailworker.h
 )
 
 target_link_libraries(ImageBrowser PRIVATE Qt6::Widgets)
\ No newline at end of file
diff --git a/imagemodel.cpp b/imagemodel.cpp
index f22f119..b6fd272 100644
--- a/imagemodel.cpp
+++ b/imagemodel.cpp
@@ -1,4 +1,5 @@
 #include "imagemodel.h"
+#include "thumbnailworker.h"
 
 #include <QDir>
 #include <QImageReader>
@@ -7,6 +8,16 @@
 ImageModel::ImageModel(QObject *parent)
     : QAbstractListModel(parent)
 {
+    m_threadPool.setMaxThreadCount(QThread::idealThreadCount());
+
+    // Simple gray placeholder
+    m_placeholder = QPixmap(128, 128);
+    m_placeholder.fill(Qt::lightGray);
+}
+
+ImageModel::~ImageModel()
+{
+    m_threadPool.waitForDone();
 }
 
 void ImageModel::setDirectory(const QString &path)
@@ -24,17 +35,23 @@ void ImageModel::setDirectory(const QString &path)
     dir.setNameFilters(filters);
     dir.setFilter(QDir::Files);
 
-    for (const QFileInfo &file : dir.entryInfoList())
+    const auto files = dir.entryInfoList();
+
+    int row = 0;
+    for (const QFileInfo &file : files)
     {
-        QImageReader reader(file.absoluteFilePath());
-        reader.setAutoTransform(true);
+        m_items.append({file.absoluteFilePath(), m_placeholder, false});
+
+        // Create worker
+        auto *worker = new ThumbnailWorker(file.absoluteFilePath(), row);
 
-        QImage image = reader.read();
-        QPixmap thumb = QPixmap::fromImage(
-            image.scaled(128, 128, Qt::KeepAspectRatio,
-                         Qt::SmoothTransformation));
+        connect(worker, &ThumbnailWorker::finished,
+                this, &ImageModel::thumbnailReady,
+                Qt::QueuedConnection);
 
-        m_items.append({file.absoluteFilePath(), thumb});
+        m_threadPool.start(worker);
+
+        row++;
     }
 
     endResetModel();
@@ -68,3 +85,15 @@ QVariant ImageModel::data(const QModelIndex &index, int role) const
 
     return {};
 }
+
+void ImageModel::thumbnailReady(int row, const QPixmap &pixmap)
+{
+    if (row < 0 || row >= m_items.size())
+        return;
+
+    m_items[row].thumbnail = pixmap;
+    m_items[row].loaded = true;
+
+    QModelIndex idx = index(row);
+    emit dataChanged(idx, idx, {Qt::DecorationRole});
+}
diff --git a/imagemodel.h b/imagemodel.h
index 3915a94..ab11e6d 100644
--- a/imagemodel.h
+++ b/imagemodel.h
@@ -3,6 +3,9 @@
 #include <QAbstractListModel>
 #include <QPixmap>
 #include <QVector>
+#include <QThreadPool>
+
+class ThumbnailWorker;
 
 class ImageModel : public QAbstractListModel
 {
@@ -10,6 +13,7 @@ class ImageModel : public QAbstractListModel
 
 public:
     explicit ImageModel(QObject *parent = nullptr);
+    ~ImageModel();
 
     void setDirectory(const QString &path);
     QString filePath(const QModelIndex &index) const;
@@ -17,12 +21,17 @@ public:
     int rowCount(const QModelIndex &parent = QModelIndex()) const override;
     QVariant data(const QModelIndex &index, int role) const override;
 
+    void thumbnailReady(int row, const QPixmap &pixmap);
+
 private:
     struct Item
     {
         QString path;
         QPixmap thumbnail;
+        bool loaded = false;
     };
 
     QVector<Item> m_items;
+    QThreadPool m_threadPool;
+    QPixmap m_placeholder;
 };
diff --git a/thumbnailworker.cpp b/thumbnailworker.cpp
new file mode 100644
index 0000000..f02d710
--- /dev/null
+++ b/thumbnailworker.cpp
@@ -0,0 +1,27 @@
+#include "thumbnailworker.h"
+#include <QImageReader>
+
+ThumbnailWorker::ThumbnailWorker(const QString &path, int row)
+    : m_path(path), m_row(row)
+{
+    setAutoDelete(true);
+}
+
+void ThumbnailWorker::run()
+{
+    QImageReader reader(m_path);
+    reader.setAutoTransform(true);
+
+    QImage image = reader.read();
+    QPixmap thumb;
+
+    if (!image.isNull())
+    {
+        thumb = QPixmap::fromImage(
+            image.scaled(128, 128,
+                         Qt::KeepAspectRatio,
+                         Qt::SmoothTransformation));
+    }
+
+    emit finished(m_row, thumb);
+}
diff --git a/thumbnailworker.h b/thumbnailworker.h
new file mode 100644
index 0000000..13df897
--- /dev/null
+++ b/thumbnailworker.h
@@ -0,0 +1,22 @@
+#pragma once
+
+#include <QRunnable>
+#include <QObject>
+#include <QPixmap>
+
+class ThumbnailWorker : public QObject, public QRunnable
+{
+    Q_OBJECT
+
+public:
+    ThumbnailWorker(const QString &path, int row);
+
+    void run() override;
+
+signals:
+    void finished(int row, const QPixmap &pixmap);
+
+private:
+    QString m_path;
+    int m_row;
+};