diff --git a/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.html b/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.html
index 6f90c11..9acb0a0 100644
--- a/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.html
+++ b/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.html
@@ -15,30 +15,48 @@
     <mat-form-field appearance="fill" class="full-width">
       <mat-label>{{ 'labelRole' | translate }}</mat-label>
       <mat-select formControlName="role" required>
-        <mat-option *ngFor="let group of userGroups" [value]="group['@id']">
-          {{ group.name }}
-        </mat-option>
+        @for (group of userGroups; track group['@id']) {
+          <mat-option [value]="group['@id']">
+            {{ group.name }}
+          </mat-option>
+        }
       </mat-select>
     </mat-form-field>
 
     <mat-form-field appearance="fill" class="full-width">
       <mat-label>{{ 'labelOrganizationalUnit' | translate }}</mat-label>
       <mat-select multiple formControlName="organizationalUnits">
-        <mat-option *ngFor="let unit of organizationalUnits" [value]="unit['@id']">
-          {{ unit.name }}
-        </mat-option>
+        @for (unit of organizationalUnits; track unit['@id']) {
+          <mat-option [value]="unit['@id']">
+            {{ unit.name }}
+          </mat-option>
+        }
       </mat-select>
     </mat-form-field>
 
     <mat-form-field appearance="fill" class="full-width">
       <mat-label>{{ 'cardView' | translate }}</mat-label>
       <mat-select formControlName="groupsView" required>
-        <mat-option *ngFor="let option of views" [value]="option.value">
-          {{ option.name }}
-        </mat-option>
+        @for (option of views; track option.value) {
+          <mat-option [value]="option.value">
+            {{ option.name }}
+          </mat-option>
+        }
       </mat-select>
     </mat-form-field>
 
+    <mat-form-field appearance="fill" class="full-width">
+      <mat-label>{{ 'userLanguage' | translate }}</mat-label>
+      <mat-select formControlName="language">
+        @for (lang of availableLanguages; track lang.code) {
+          <mat-option [value]="lang.code">
+            {{ lang.label }}
+          </mat-option>
+        }
+      </mat-select>
+      <mat-hint>{{ 'userLanguageHint' | translate }}</mat-hint>
+    </mat-form-field>
+
     <mat-form-field appearance="fill" class="full-width">
       <mat-label>{{ 'clientsPerPage' | translate }}</mat-label>
       <input matInput formControlName="clientsPerPage" type="number" min="1" [placeholder]="'default20' | translate">
diff --git a/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.ts b/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.ts
index 308da61..bceaa5b 100644
--- a/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.ts
+++ b/ogWebconsole/src/app/components/admin/users/users/add-user-modal/add-user-modal.component.ts
@@ -36,6 +36,8 @@ export class AddUserModalComponent implements OnInit {
     { value: 'list', name: 'Listado' },
   ];
 
+  readonly availableLanguages: { code: string; label: string }[];
+
   constructor(
     public dialogRef: MatDialogRef<AddUserModalComponent>,
     @Inject(MAT_DIALOG_DATA) public data: any,
@@ -46,12 +48,15 @@ export class AddUserModalComponent implements OnInit {
     private configService: ConfigService
   ) {
     this.baseUrl = this.configService.apiUrl;
+    const langs = this.configService.languages;
+    this.availableLanguages = Object.keys(langs).map(code => ({ code, label: langs[code] }));
     this.userForm = this.fb.group({
       username: ['', Validators.required],
       password: ['', Validators.required],
       role: ['', Validators.required],
       groupsView: ['card', Validators.required],
       clientsPerPage: [null, [Validators.min(1)]],
+      language: ['es'],
       organizationalUnits: [[]]
     });
 
@@ -87,7 +92,8 @@ export class AddUserModalComponent implements OnInit {
           role: response.userGroups.length > 0 ? response.userGroups[0]['@id'] : null,
           organizationalUnits: organizationalUnitIds,
           groupsView: response.groupsView,
-          clientsPerPage: response.clientsPerPage ?? null
+          clientsPerPage: response.clientsPerPage ?? null,
+          language: response.language ?? 'es'
         });
 
         this.userId = response['@id'];
@@ -114,7 +120,8 @@ export class AddUserModalComponent implements OnInit {
         enabled: true,
         userGroups: [this.userForm.value.role],
         groupsView: this.userForm.value.groupsView,
-        clientsPerPage: this.userForm.value.clientsPerPage || null
+        clientsPerPage: this.userForm.value.clientsPerPage || null,
+        language: this.userForm.value.language || null
       };
 
       if (!this.userId && this.userForm.value.password) {
diff --git a/ogWebconsole/src/app/layout/header/header.component.ts b/ogWebconsole/src/app/layout/header/header.component.ts
index 4196b4f..4ef3bd3 100644
--- a/ogWebconsole/src/app/layout/header/header.component.ts
+++ b/ogWebconsole/src/app/layout/header/header.component.ts
@@ -34,7 +34,14 @@ export class HeaderComponent implements OnInit {
   ngOnInit(): void {
     this.breakpointObserver.observe(['(max-width: 576px)']).subscribe((result) => {
       this.isSmallScreen = result.matches;
-    })
+    });
+
+    // Aplicar idioma guardado: el del JWT (servidor) tiene prioridad sobre localStorage
+    const jwtLang = this.auth.language;
+    const localLang = localStorage.getItem('language');
+    const langToApply = jwtLang || localLang || 'es';
+    this.translate.use(langToApply);
+    localStorage.setItem('language', langToApply);
   }
 
   get availableLanguages() {
diff --git a/ogWebconsole/src/app/services/auth.service.ts b/ogWebconsole/src/app/services/auth.service.ts
index 3c18231..c88d1b0 100644
--- a/ogWebconsole/src/app/services/auth.service.ts
+++ b/ogWebconsole/src/app/services/auth.service.ts
@@ -18,6 +18,7 @@ interface JwtPayload {
   uuid: string;
   groupsView: string;
   clientsPerPage: number | null;
+  language: string | null;
 }
 
 @Injectable({ providedIn: 'root' })
@@ -103,6 +104,11 @@ export class AuthService {
     return this.tokenPayload?.clientsPerPage ?? null;
   }
 
+  /** Idioma preferido del usuario */
+  get language(): string | null {
+    return this.tokenPayload?.language ?? null;
+  }
+
   /**
  * Devuelve el rol principal del usuario según prioridad.
  */
diff --git a/ogWebconsole/src/locale/cat.json b/ogWebconsole/src/locale/cat.json
index 973cc78..76153a0 100644
--- a/ogWebconsole/src/locale/cat.json
+++ b/ogWebconsole/src/locale/cat.json
@@ -238,6 +238,8 @@
     "clientSelectStepText": "Selecciona un client per veure les traces associades.",
     "clientsPerPage": "Clients per pàgina",
     "clientsPerPageHint": "Nombre de clients mostrats per pàgina al llistat",
+    "userLanguage": "Idioma preferit",
+    "userLanguageHint": "Idioma de la interfície per a aquest usuari",
     "clientSuccessfullyRemovedFromThe": "Client eliminat de la xarxa correctament",
     "clientsViewStepText": "Visualització dels clients de la unitat organitzativa seleccionada",
     "clientUpdatedSuccessfully": "Client actualitzat correctament",
diff --git a/ogWebconsole/src/locale/en.json b/ogWebconsole/src/locale/en.json
index 8afc28a..c87fbce 100644
--- a/ogWebconsole/src/locale/en.json
+++ b/ogWebconsole/src/locale/en.json
@@ -238,6 +238,8 @@
     "clientSelectStepText": "Select a client to see the associated traces.",
     "clientsPerPage": "Clients per page",
     "clientsPerPageHint": "Number of clients shown per page in the list",
+    "userLanguage": "Preferred language",
+    "userLanguageHint": "Interface language for this user",
     "clientSuccessfullyRemovedFromThe": "Client successfully removed from the network",
     "clientsViewStepText": "Display of the selected organizational unit's clients",
     "clientUpdatedSuccessfully": "Client updated successfully",
diff --git a/ogWebconsole/src/locale/es.json b/ogWebconsole/src/locale/es.json
index a476d54..61dd482 100644
--- a/ogWebconsole/src/locale/es.json
+++ b/ogWebconsole/src/locale/es.json
@@ -238,6 +238,8 @@
     "clientSelectStepText": "Selecciona un cliente para ver las trazas asociadas.",
     "clientsPerPage": "Clientes por página",
     "clientsPerPageHint": "Número de clientes mostrados por página en el listado",
+    "userLanguage": "Idioma preferido",
+    "userLanguageHint": "Idioma de la interfaz para este usuario",
     "clientSuccessfullyRemovedFromThe": "Cliente eliminado de la red con éxito",
     "clientsViewStepText": "Visualización de los clientes de la unidad organizativa seleccionada",
     "clientUpdatedSuccessfully": "Cliente actualizado con éxito",