diff --git a/pom.xml b/pom.xml
index ffbab1e..c46daee 100644
--- a/pom.xml
+++ b/pom.xml
@@ -336,7 +336,7 @@
         <configuration>
           <executable>${java.home}/bin/java</executable>
           <workingDirectory>${project.basedir}</workingDirectory>
-          <commandlineArgs>-Djava.net.preferIPv6Addresses=true -Xmx512m --module-path target/dependency --add-modules ${javafx.modules} -cp target/classes:target/dependency/* ${app.main.class}</commandlineArgs>
+          <commandlineArgs>-Djava.net.preferIPv6Addresses=true -Xmx512m --sun-misc-unsafe-memory-access=allow --module-path target/dependency --add-modules ${javafx.modules} -cp target/classes:target/dependency/* ${app.main.class}</commandlineArgs>
         </configuration>
       </plugin>
 
@@ -613,6 +613,7 @@
                   <javaOptions>
                     <!--javaOption>-Djava.net.preferIPv6Addresses=true</javaOption-->
                     <javaOption>-Xmx512m</javaOption>
+                    <javaOption>--sun-misc-unsafe-memory-access=allow</javaOption>
                   </javaOptions>
 
                   <!-- Output directory -->
diff --git a/src/main/java/MarkNote.java b/src/main/java/MarkNote.java
index 1fe4316..f3ec1e2 100644
--- a/src/main/java/MarkNote.java
+++ b/src/main/java/MarkNote.java
@@ -31,7 +31,15 @@
 import ui.WelcomeTab;
 import ui.CommitDialog;
 import ui.AddRemoteDialog;
+import ui.UpdateDialog;
 import java.util.List;
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import services.UpdateChecker;
 import utils.Debouncer;
 import utils.DocumentService;
 import utils.GitService;
@@ -413,6 +421,7 @@ public void start(Stage stage) {
                 if (config.isOpenDocOnStart() && !config.isShowWelcomePage()) {
                     addNewDocument();
                 }
+                checkForUpdatesOnStartup();
             });
             splash.show();
         } else {
@@ -424,6 +433,7 @@ public void start(Stage stage) {
             if (config.isOpenDocOnStart() && !config.isShowWelcomePage()) {
                 addNewDocument();
             }
+            checkForUpdatesOnStartup();
         }
     }
 
@@ -545,7 +555,10 @@ private MenuBar createMenuBar() {
         MenuItem aboutItem = new MenuItem(messages.getString("menu.help.about"));
         aboutItem.setOnAction(e -> showAboutDialog());
 
-        helpMenu.getItems().addAll(optionsItem, new SeparatorMenuItem(), aboutItem);
+        MenuItem checkUpdateItem = new MenuItem(messages.getString("menu.help.checkUpdate"));
+        checkUpdateItem.setOnAction(e -> checkForUpdatesManual());
+
+        helpMenu.getItems().addAll(optionsItem, checkUpdateItem, new SeparatorMenuItem(), aboutItem);
 
         // == Menu Édition ==
         Menu editMenu = new Menu(messages.getString("menu.edit"));
@@ -1510,6 +1523,75 @@ private void showAboutDialog() {
         about.showAndWait();
     }
 
+    private void checkForUpdatesOnStartup() {
+        if (!config.isAutoCheckUpdate()) return;
+        new Thread(() -> {
+            UpdateChecker.VersionInfo info =
+                    UpdateChecker.checkForUpdate(messages.getString("app.version"));
+            if (info == null) return;
+            if (info.tagName().equals(config.getSkipVersion())) return;
+            Platform.runLater(() -> showUpdateDialog(info));
+        }, "update-check").start();
+    }
+
+    private void checkForUpdatesManual() {
+        new Thread(() -> {
+            UpdateChecker.VersionInfo info =
+                    UpdateChecker.checkForUpdate(messages.getString("app.version"));
+            Platform.runLater(() -> {
+                if (info == null) {
+                    Alert a = new Alert(Alert.AlertType.INFORMATION);
+                    a.initOwner(primaryStage);
+                    a.setTitle(messages.getString("update.uptodate.title"));
+                    a.setContentText(messages.getString("update.uptodate.content")
+                            .replace("{0}", messages.getString("app.version")));
+                    a.showAndWait();
+                } else {
+                    showUpdateDialog(info);
+                }
+            });
+        }, "update-check-manual").start();
+    }
+
+    private void showUpdateDialog(UpdateChecker.VersionInfo info) {
+        UpdateDialog dlg = new UpdateDialog(messages, primaryStage, info,
+                messages.getString("app.version"));
+        UpdateDialog.UpdateResult result = dlg.showAndGet();
+        if (result == UpdateDialog.UpdateResult.SKIP) {
+            config.setSkipVersion(info.tagName());
+            config.save();
+        } else if (result == UpdateDialog.UpdateResult.UPDATE) {
+            downloadAndInstall(info);
+        }
+    }
+
+    private void downloadAndInstall(UpdateChecker.VersionInfo info) {
+        new Thread(() -> {
+            try {
+                String suffix = info.assetName()
+                        .substring(info.assetName().lastIndexOf('.'));
+                Path dest = Files.createTempFile("marknote-update-", suffix);
+                HttpClient client = HttpClient.newBuilder()
+                        .followRedirects(HttpClient.Redirect.ALWAYS)
+                        .build();
+                client.send(
+                        HttpRequest.newBuilder(URI.create(info.downloadUrl()))
+                                .header("Accept", "application/octet-stream")
+                                .build(),
+                        HttpResponse.BodyHandlers.ofFile(dest));
+                java.awt.Desktop.getDesktop().open(dest.toFile());
+            } catch (Exception e) {
+                Platform.runLater(() -> {
+                    Alert err = new Alert(Alert.AlertType.ERROR);
+                    err.initOwner(primaryStage);
+                    err.setTitle(messages.getString("update.error.title"));
+                    err.setContentText(e.getMessage());
+                    err.showAndWait();
+                });
+            }
+        }, "update-download").start();
+    }
+
     /**
      * Ouvre un fichier CSS de thème dans un ThemeTab.
      */
diff --git a/src/main/java/config/AppConfig.java b/src/main/java/config/AppConfig.java
index 013d586..4c7a268 100644
--- a/src/main/java/config/AppConfig.java
+++ b/src/main/java/config/AppConfig.java
@@ -39,6 +39,9 @@ public class AppConfig {
     private String gitUsername   = "token";
     private String gitToolbarMode = "standard";
 
+    private boolean autoCheckUpdate = true;
+    private String skipVersion = null;
+
     public record PanelState(boolean visible, boolean docked, String zone) {}
 
     /**
@@ -96,6 +99,11 @@ public void load() {
                     gitUsername = line.substring("gitUsername=".length()).trim();
                 } else if (line.startsWith("gitToolbarMode=")) {
                     gitToolbarMode = line.substring("gitToolbarMode=".length()).trim();
+                } else if (line.startsWith("autoCheckUpdate=")) {
+                    autoCheckUpdate = Boolean.parseBoolean(line.substring("autoCheckUpdate=".length()).trim());
+                } else if (line.startsWith("skipVersion=")) {
+                    String v = line.substring("skipVersion=".length()).trim();
+                    skipVersion = v.isEmpty() ? null : v;
                 } else if (line.startsWith("panelState=")) {
                     String raw = line.substring("panelState=".length()).trim();
                     String[] parts = raw.split("\\|", -1);
@@ -138,6 +146,8 @@ public void save() {
             lines.add("gitToken=" + gitToken);
             lines.add("gitUsername=" + gitUsername);
             lines.add("gitToolbarMode=" + gitToolbarMode);
+            lines.add("autoCheckUpdate=" + autoCheckUpdate);
+            lines.add("skipVersion=" + (skipVersion != null ? skipVersion : ""));
             for (Map.Entry<String, PanelState> entry : panelStates.entrySet()) {
                 PanelState state = entry.getValue();
                 lines.add("panelState=" + entry.getKey() + "|" + state.visible() + "|" + state.docked() + "|" + state.zone());
@@ -311,6 +321,12 @@ public void setReattachDiagramOnTabClose(boolean reattachDiagramOnTabClose) {
     public String getGitToolbarMode() { return gitToolbarMode; }
     public void setGitToolbarMode(String mode) { this.gitToolbarMode = (mode != null && !mode.isBlank()) ? mode : "standard"; }
 
+    public boolean isAutoCheckUpdate() { return autoCheckUpdate; }
+    public void setAutoCheckUpdate(boolean autoCheckUpdate) { this.autoCheckUpdate = autoCheckUpdate; }
+
+    public String getSkipVersion() { return skipVersion; }
+    public void setSkipVersion(String version) { this.skipVersion = version; }
+
     /**
      * Supprime un fichier de la liste des récents.
      *
diff --git a/src/main/java/services/UpdateChecker.java b/src/main/java/services/UpdateChecker.java
new file mode 100644
index 0000000..3a0dd51
--- /dev/null
+++ b/src/main/java/services/UpdateChecker.java
@@ -0,0 +1,88 @@
+package services;
+
+import java.net.URI;
+import java.net.http.HttpClient;
+import java.net.http.HttpRequest;
+import java.net.http.HttpResponse;
+import java.time.Duration;
+
+import org.json.simple.JSONArray;
+import org.json.simple.JSONObject;
+import org.json.simple.parser.JSONParser;
+
+public class UpdateChecker {
+
+    private static final String API_URL =
+            "https://api.github.com/repos/mcgivrer/MarkNote/releases/latest";
+
+    public record VersionInfo(String tagName, String downloadUrl, String assetName) {}
+
+    public static VersionInfo checkForUpdate(String currentVersion) {
+        try {
+            HttpClient client = HttpClient.newBuilder()
+                    .connectTimeout(Duration.ofSeconds(10))
+                    .build();
+            HttpRequest req = HttpRequest.newBuilder(URI.create(API_URL))
+                    .header("Accept", "application/vnd.github+json")
+                    .header("X-GitHub-Api-Version", "2022-11-28")
+                    .build();
+            HttpResponse<String> resp = client.send(req, HttpResponse.BodyHandlers.ofString());
+            if (resp.statusCode() != 200) return null;
+
+            JSONObject json = (JSONObject) new JSONParser().parse(resp.body());
+            String tagName = (String) json.get("tag_name");
+            if (tagName == null || !isNewer(tagName, currentVersion)) return null;
+
+            JSONArray assets = (JSONArray) json.get("assets");
+            JSONObject asset = selectAsset(assets);
+            if (asset == null) return null;
+
+            return new VersionInfo(tagName,
+                    (String) asset.get("browser_download_url"),
+                    (String) asset.get("name"));
+        } catch (Exception e) {
+            return null;
+        }
+    }
+
+    private static boolean isNewer(String remote, String current) {
+        int[] r = parseParts(remote.startsWith("v") ? remote.substring(1) : remote);
+        int[] c = parseParts(current.startsWith("v") ? current.substring(1) : current);
+        int len = Math.max(r.length, c.length);
+        for (int i = 0; i < len; i++) {
+            int rv = i < r.length ? r[i] : 0;
+            int cv = i < c.length ? c[i] : 0;
+            if (rv > cv) return true;
+            if (rv < cv) return false;
+        }
+        return false;
+    }
+
+    private static int[] parseParts(String version) {
+        String[] parts = version.split("\\.");
+        int[] ints = new int[parts.length];
+        for (int i = 0; i < parts.length; i++) {
+            try {
+                ints[i] = Integer.parseInt(parts[i]);
+            } catch (NumberFormatException e) {
+                ints[i] = 0;
+            }
+        }
+        return ints;
+    }
+
+    private static JSONObject selectAsset(JSONArray assets) {
+        if (assets == null) return null;
+        String os = System.getProperty("os.name").toLowerCase();
+        String ext = os.contains("win") ? ".exe" : os.contains("mac") ? ".dmg" : ".deb";
+        for (Object o : assets) {
+            JSONObject a = (JSONObject) o;
+            String name = (String) a.get("name");
+            String state = (String) a.get("state");
+            if ("uploaded".equals(state) && name != null && name.endsWith(ext)) {
+                return a;
+            }
+        }
+        return null;
+    }
+}
diff --git a/src/main/java/ui/UpdateDialog.java b/src/main/java/ui/UpdateDialog.java
new file mode 100644
index 0000000..e989de1
--- /dev/null
+++ b/src/main/java/ui/UpdateDialog.java
@@ -0,0 +1,69 @@
+package ui;
+
+import java.util.ResourceBundle;
+
+import javafx.geometry.Insets;
+import javafx.geometry.Pos;
+import javafx.scene.Scene;
+import javafx.scene.control.Button;
+import javafx.scene.control.CheckBox;
+import javafx.scene.control.Label;
+import javafx.scene.layout.HBox;
+import javafx.scene.layout.VBox;
+import javafx.stage.Modality;
+import javafx.stage.Stage;
+import javafx.stage.Window;
+
+import services.UpdateChecker.VersionInfo;
+
+public class UpdateDialog {
+
+    public enum UpdateResult { UPDATE, DECLINE, SKIP }
+
+    private final Stage dialog;
+    private UpdateResult result = UpdateResult.DECLINE;
+
+    public UpdateDialog(ResourceBundle messages, Window owner, VersionInfo info, String currentVersion) {
+        dialog = new Stage();
+        dialog.initModality(Modality.APPLICATION_MODAL);
+        dialog.initOwner(owner);
+        dialog.setTitle(messages.getString("update.available.title"));
+        dialog.setResizable(false);
+
+        Label headerLabel = new Label(
+                messages.getString("update.available.header").replace("{0}", info.tagName()));
+        headerLabel.setStyle("-fx-font-size: 14px; -fx-font-weight: bold;");
+
+        Label bodyLabel = new Label(
+                messages.getString("update.available.content").replace("{0}", currentVersion));
+
+        CheckBox skipBox = new CheckBox(messages.getString("update.skip"));
+
+        Button downloadBtn = new Button(messages.getString("update.download"));
+        downloadBtn.setDefaultButton(true);
+        downloadBtn.setOnAction(e -> {
+            result = UpdateResult.UPDATE;
+            dialog.close();
+        });
+
+        Button declineBtn = new Button(messages.getString("update.decline"));
+        declineBtn.setOnAction(e -> {
+            result = skipBox.isSelected() ? UpdateResult.SKIP : UpdateResult.DECLINE;
+            dialog.close();
+        });
+
+        HBox buttons = new HBox(10, downloadBtn, declineBtn);
+        buttons.setAlignment(Pos.CENTER_RIGHT);
+
+        VBox root = new VBox(12, headerLabel, bodyLabel, skipBox, buttons);
+        root.setPadding(new Insets(20));
+        root.setPrefWidth(420);
+
+        dialog.setScene(new Scene(root));
+    }
+
+    public UpdateResult showAndGet() {
+        dialog.showAndWait();
+        return result;
+    }
+}
diff --git a/src/main/resources/i18n/messages_de.properties b/src/main/resources/i18n/messages_de.properties
index 8659f20..09f8112 100644
--- a/src/main/resources/i18n/messages_de.properties
+++ b/src/main/resources/i18n/messages_de.properties
@@ -436,3 +436,16 @@ git.operation.fetch=Fetch\u2026
 # Lesemodus
 menu.view.readingMode=Lesemodus
 reading.mode.exit=Lesemodus beenden
+
+# Update-Prüfung
+menu.help.checkUpdate=Nach Updates suchen...
+update.available.title=Neue Version verfügbar
+update.available.header=MarkNote {0} ist verfügbar
+update.available.content=Sie verwenden derzeit Version {0}.
+update.skip=Diese Version überspringen
+update.download=Herunterladen und installieren
+update.decline=Später
+update.uptodate.title=Aktuell
+update.uptodate.content=Sie verwenden die neueste Version von MarkNote ({0}).
+update.error.title=Update-Prüfung fehlgeschlagen
+update.error.content=Updates konnten nicht geprüft werden. Bitte versuchen Sie es erneut.
diff --git a/src/main/resources/i18n/messages_en.properties b/src/main/resources/i18n/messages_en.properties
index d55647f..eb023c7 100644
--- a/src/main/resources/i18n/messages_en.properties
+++ b/src/main/resources/i18n/messages_en.properties
@@ -438,3 +438,16 @@ git.operation.fetch=Fetching\u2026
 # Reading mode
 menu.view.readingMode=Enter Reading Mode
 reading.mode.exit=Exit Reading Mode
+
+# Update check
+menu.help.checkUpdate=Check for New Version...
+update.available.title=New Version Available
+update.available.header=MarkNote {0} is available
+update.available.content=You are currently running version {0}.
+update.skip=Skip this version
+update.download=Download & Install
+update.decline=Later
+update.uptodate.title=Up to Date
+update.uptodate.content=You are running the latest version of MarkNote ({0}).
+update.error.title=Update Check Failed
+update.error.content=Unable to check for updates. Please try again later.
diff --git a/src/main/resources/i18n/messages_es.properties b/src/main/resources/i18n/messages_es.properties
index 6d0cc59..bfb4a2d 100644
--- a/src/main/resources/i18n/messages_es.properties
+++ b/src/main/resources/i18n/messages_es.properties
@@ -437,3 +437,16 @@ git.operation.fetch=Recuperando\u2026
 menu.view.readingMode=Modo lectura
 reading.mode.exit=Salir del modo lectura
 
+# Comprobación de actualizaciones
+menu.help.checkUpdate=Buscar nueva versión...
+update.available.title=Nueva versión disponible
+update.available.header=MarkNote {0} está disponible
+update.available.content=Está utilizando actualmente la versión {0}.
+update.skip=Omitir esta versión
+update.download=Descargar e instalar
+update.decline=Más tarde
+update.uptodate.title=Actualizado
+update.uptodate.content=Está utilizando la última versión de MarkNote ({0}).
+update.error.title=Error al comprobar actualizaciones
+update.error.content=No se pudo comprobar si hay actualizaciones. Inténtelo de nuevo.
+
diff --git a/src/main/resources/i18n/messages_fr.properties b/src/main/resources/i18n/messages_fr.properties
index 4cf0adb..91c5dac 100644
--- a/src/main/resources/i18n/messages_fr.properties
+++ b/src/main/resources/i18n/messages_fr.properties
@@ -439,3 +439,16 @@ git.operation.fetch=R\u00e9cup\u00e9rer\u2026
 # Mode lecture
 menu.view.readingMode=Mode lecture
 reading.mode.exit=Quitter le mode lecture
+
+# Vérification de mise à jour
+menu.help.checkUpdate=Vérifier les mises à jour...
+update.available.title=Nouvelle version disponible
+update.available.header=MarkNote {0} est disponible
+update.available.content=Vous utilisez actuellement la version {0}.
+update.skip=Ignorer cette version
+update.download=Télécharger et installer
+update.decline=Plus tard
+update.uptodate.title=À jour
+update.uptodate.content=Vous utilisez la dernière version de MarkNote ({0}).
+update.error.title=Échec de la vérification
+update.error.content=Impossible de vérifier les mises à jour. Veuillez réessayer.
diff --git a/src/main/resources/i18n/messages_it.properties b/src/main/resources/i18n/messages_it.properties
index 26ba6dd..4525866 100644
--- a/src/main/resources/i18n/messages_it.properties
+++ b/src/main/resources/i18n/messages_it.properties
@@ -436,3 +436,16 @@ git.operation.fetch=Aggiornamento in corso\u2026
 menu.view.readingMode=Modalit\u00e0 lettura
 reading.mode.exit=Esci dalla modalit\u00e0 lettura
 
+# Controllo aggiornamenti
+menu.help.checkUpdate=Verifica nuova versione...
+update.available.title=Nuova versione disponibile
+update.available.header=MarkNote {0} \u00e8 disponibile
+update.available.content=Stai attualmente usando la versione {0}.
+update.skip=Ignora questa versione
+update.download=Scarica e installa
+update.decline=Pi\u00f9 tardi
+update.uptodate.title=Aggiornato
+update.uptodate.content=Stai usando l'ultima versione di MarkNote ({0}).
+update.error.title=Verifica aggiornamenti fallita
+update.error.content=Impossibile verificare gli aggiornamenti. Riprova pi\u00f9 tardi.
+