diff --git a/src/main/java/core/packetproxy/PacketProxy.java b/src/main/java/core/packetproxy/PacketProxy.java
index 31f61e0c..8ecf5ee3 100644
--- a/src/main/java/core/packetproxy/PacketProxy.java
+++ b/src/main/java/core/packetproxy/PacketProxy.java
@@ -18,7 +18,6 @@
 import java.io.File;
 import java.sql.SQLException;
 import javax.swing.*;
-import packetproxy.common.AppVersion;
 import packetproxy.common.I18nString;
 import packetproxy.common.Utils;
 import packetproxy.gui.GUIMain;
@@ -118,8 +117,7 @@ public void start() throws Exception {
 	}
 
 	private void startGUI() throws Exception {
-		var version = AppVersion.get();
-		gui = GUIMain.getInstance(String.format("PacketProxy %s", version));
+		gui = GUIMain.getInstance();
 		gui.setVisible(true);
 	}
 }
diff --git a/src/main/java/core/packetproxy/common/ProjectDisplayName.java b/src/main/java/core/packetproxy/common/ProjectDisplayName.java
new file mode 100644
index 00000000..c6c9d125
--- /dev/null
+++ b/src/main/java/core/packetproxy/common/ProjectDisplayName.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright 2026 DeNA Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package packetproxy.common;
+
+import org.apache.commons.io.FilenameUtils;
+import packetproxy.model.Database;
+
+public final class ProjectDisplayName {
+
+	private static final String UNKNOWN = "Unknown";
+	private static final String DEFAULT = "Default";
+	private static final String TEMPORARY = "Temporary";
+
+	private ProjectDisplayName() {
+	}
+
+	public static String get() {
+		try {
+			var dbPath = Database.getInstance().getDatabasePath();
+			if (dbPath == null) {
+
+				return UNKNOWN;
+			}
+			return fromFileName(dbPath.getFileName().toString());
+		} catch (Exception e) {
+
+			return UNKNOWN;
+		}
+	}
+
+	static String fromFileName(String fileName) {
+		if (fileName.equals("resources.sqlite3")) {
+
+			return DEFAULT;
+		}
+		if (fileName.equals("resources_temp.sqlite3")) {
+
+			return TEMPORARY;
+		}
+		if (fileName.startsWith("packetproxy-") && fileName.matches("packetproxy-\\d{8}-\\d{6}\\.sqlite3")) {
+
+			return TEMPORARY;
+		}
+		return FilenameUtils.removeExtension(fileName);
+	}
+}
diff --git a/src/main/java/core/packetproxy/gui/GUIMain.java b/src/main/java/core/packetproxy/gui/GUIMain.java
index f91cac5e..dadbecb0 100644
--- a/src/main/java/core/packetproxy/gui/GUIMain.java
+++ b/src/main/java/core/packetproxy/gui/GUIMain.java
@@ -30,9 +30,14 @@
 import javax.swing.text.DefaultEditorKit;
 import javax.swing.text.JTextComponent;
 import javax.swing.text.Keymap;
+import packetproxy.common.AppVersion;
 import packetproxy.common.FontManager;
 import packetproxy.common.I18nString;
+import packetproxy.common.ProjectDisplayName;
+import packetproxy.model.Database;
+import packetproxy.model.Database.DatabaseMessage;
 import packetproxy.model.InterceptModel;
+import packetproxy.model.PropertyChangeEventType;
 import packetproxy.util.PacketProxyUtility;
 
 public class GUIMain extends JFrame implements PropertyChangeListener {
@@ -55,18 +60,10 @@ public enum Panes {
 		HISTORY, INTERCEPT, RESENDER, VULCHECKHELPER, BULKSENDER, EXTENSIONS, OPTIONS, LOG
 	};
 
-	public static GUIMain getInstance(String title) throws Exception {
-		if (instance == null) {
-
-			instance = new GUIMain(title);
-		}
-		return instance;
-	}
-
 	public static GUIMain getInstance() throws Exception {
 		if (instance == null) {
 
-			throw new Exception("GUIMain instance not found.");
+			instance = new GUIMain();
 		}
 		return instance;
 	}
@@ -97,13 +94,18 @@ private String getPaneString(Panes num) {
 		return null;
 	}
 
-	private GUIMain(String title) {
+	private GUIMain() {
 		try {
-
 			setIcon();
 			gui_history = initProjectAndHistory();
 			setLookandFeel();
-			setTitle(title);
+
+			// Register for database events
+			Database.getInstance().addPropertyChangeListener(this);
+
+			// Set initial title with project name
+			updateTitle();
+
 			setBounds(10, 10, 1100, 850);
 			enableFullScreenForMac(this);
 
@@ -326,8 +328,14 @@ private void setInterceptDownLight() {
 		tabbedpane.repaint();
 	}
 
+	public void updateTitle() {
+		var titleText = String.format("PacketProxy %s - %s", AppVersion.get(), ProjectDisplayName.get());
+		setTitle(titleText);
+	}
+
 	@Override
 	public void propertyChange(PropertyChangeEvent evt) {
+		// Handle intercept model events
 		if (interceptModel.getData() == null) {
 
 			setInterceptDownLight();
@@ -335,5 +343,15 @@ public void propertyChange(PropertyChangeEvent evt) {
 
 			setInterceptHighLight();
 		}
+
+		// Handle database reconnection events to update title
+		if (PropertyChangeEventType.DATABASE_MESSAGE.matches(evt)) {
+			if (evt.getNewValue() instanceof DatabaseMessage) {
+				DatabaseMessage msg = (DatabaseMessage) evt.getNewValue();
+				if (msg == DatabaseMessage.RECONNECT) {
+					SwingUtilities.invokeLater(this::updateTitle);
+				}
+			}
+		}
 	}
 }
diff --git a/src/test/java/packetproxy/common/ProjectDisplayNameTest.java b/src/test/java/packetproxy/common/ProjectDisplayNameTest.java
new file mode 100644
index 00000000..9c5db1c6
--- /dev/null
+++ b/src/test/java/packetproxy/common/ProjectDisplayNameTest.java
@@ -0,0 +1,43 @@
+/*
+ * Copyright 2026 DeNA Co., Ltd.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package packetproxy.common;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+public class ProjectDisplayNameTest {
+
+	@Test
+	public void fromFileName_defaultDatabase() {
+		assertEquals("Default", ProjectDisplayName.fromFileName("resources.sqlite3"));
+	}
+
+	@Test
+	public void fromFileName_namedProject() {
+		assertEquals("myproject", ProjectDisplayName.fromFileName("myproject.sqlite3"));
+	}
+
+	@Test
+	public void fromFileName_temporaryTimestampedProject() {
+		assertEquals("Temporary", ProjectDisplayName.fromFileName("packetproxy-20260409-193537.sqlite3"));
+	}
+
+	@Test
+	public void fromFileName_resourcesTemp() {
+		assertEquals("Temporary", ProjectDisplayName.fromFileName("resources_temp.sqlite3"));
+	}
+}