diff --git a/app/src/androidTest/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivityTest.kt b/app/src/androidTest/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivityTest.kt
index da13ca8..62af7b7 100644
--- a/app/src/androidTest/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivityTest.kt
+++ b/app/src/androidTest/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivityTest.kt
@@ -32,7 +32,7 @@ class LoginActivityTest {
         onView(withId(R.id.button))
             .perform(click())
 
-        onView(withText("Riempire tutti i campi"))
+        onView(withText(R.string.login_empty_field))
             .inRoot(withDecorView(not(activityRule.activity.window.decorView)))
            .check(matches(isDisplayed()))
     }
@@ -40,13 +40,14 @@ class LoginActivityTest {
     @Test
     fun loginWithEmptyUsername() {
         onView(withId(R.id.instanceServer))
-            .perform(typeText("instanceServer"))
+            .perform(typeText("https://wekan.com"))
         onView(withId(R.id.password))
             .perform(typeText("password"))
         closeSoftKeyboard()
         onView(withId(R.id.button))
             .perform(click())
-        onView(withText("Riempire tutti i campi"))
+
+        onView(withText(R.string.login_empty_field))
             .inRoot(withDecorView(not(activityRule.activity.window.decorView)))
             .check(matches(isDisplayed()))
 
@@ -55,15 +56,32 @@ class LoginActivityTest {
     @Test
     fun loginWithEmptyPassword() {
         onView(withId(R.id.instanceServer))
-            .perform(typeText("instanceServer"))
+            .perform(typeText("https://wekan.com"))
         onView(withId(R.id.username))
             .perform(typeText("username"))
         closeSoftKeyboard()
         onView(withId(R.id.button))
             .perform(click())
-        onView(withText("Riempire tutti i campi"))
+
+        onView(withText(R.string.login_empty_field))
+            .inRoot(withDecorView(not(activityRule.activity.window.decorView)))
+            .check(matches(isDisplayed()))
+    }
+
+    @Test
+    fun loginWithUnformedInstance(){
+        onView(withId(R.id.instanceServer))
+            .perform(typeText("not an URL"))
+        onView(withId(R.id.username))
+            .perform(typeText("username"))
+        onView(withId(R.id.password))
+            .perform(typeText("password"))
+        closeSoftKeyboard()
+        onView(withId(R.id.button))
+            .perform(click())
+
+        onView(withText(R.string.login_unformed_instance))
             .inRoot(withDecorView(not(activityRule.activity.window.decorView)))
             .check(matches(isDisplayed()))
     }
-    
 }
\ No newline at end of file
diff --git a/app/src/main/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivity.kt b/app/src/main/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivity.kt
index 8e92d4f..811db1a 100644
--- a/app/src/main/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivity.kt
+++ b/app/src/main/java/it/unisannio/ding/ids/wedroid/app/view/LoginActivity.kt
@@ -3,6 +3,7 @@ package it.unisannio.ding.ids.wedroid.app.view
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import android.view.View
+import android.webkit.URLUtil
 import android.widget.Toast
 import it.unisannio.ding.ids.wedroid.app.R
 import it.unisannio.ding.ids.wedroid.app.util.SharedPreferenceHelper
@@ -32,17 +33,24 @@ class LoginActivity : AppCompatActivity() {
 
     fun loginButton(v: View) {
         if (username.text.isBlank() || instanceServer.text.isBlank() || password.text.isBlank()) {
-            Toast.makeText(this, "Riempire tutti i campi", Toast.LENGTH_LONG)
+            Toast.makeText(this, R.string.login_empty_field, Toast.LENGTH_LONG)
                 .show()
             return
         }
 
         val userNameText = username.text.toString()
         val passwordText = password.text.toString()
+        val instanceServerText = instanceServer.text.toString()
+
+        if (!URLUtil.isValidUrl(instanceServerText)){
+            Toast.makeText(this, R.string.login_unformed_instance, Toast.LENGTH_LONG)
+                .show()
+            return
+        }
 
         val service = Retrofit.Builder()
             .addConverterFactory(GsonConverterFactory.create())
-            .baseUrl(instanceServer.text.toString())
+            .baseUrl(instanceServerText)
             .build()
             .create(LoginService::class.java)
 
@@ -50,7 +58,7 @@ class LoginActivity : AppCompatActivity() {
             override fun onFailure(call: Call<UserPrototype>, t: Throwable) {
                 Toast.makeText(
                     applicationContext,
-                    "Controlla la tua connessione internet",
+                    R.string.login_network_error,
                     Toast.LENGTH_LONG
                 ).show()
             }
@@ -60,7 +68,7 @@ class LoginActivity : AppCompatActivity() {
                 if (response.code() != 200) {
                     Toast.makeText(
                         applicationContext,
-                        "Credenziali non corrette",
+                        R.string.login_wrong_field,
                         Toast.LENGTH_LONG
                     ).show()
                     return
@@ -72,7 +80,7 @@ class LoginActivity : AppCompatActivity() {
 
                 Toast.makeText(
                     applicationContext,
-                    "Login effettuato con successo",
+                    R.string.login_success,
                     Toast.LENGTH_LONG
                 ).show()
 
diff --git a/app/src/main/res/values/strings.xml b/app/src/main/res/values/strings.xml
index 4cb76fa..c916639 100644
--- a/app/src/main/res/values/strings.xml
+++ b/app/src/main/res/values/strings.xml
@@ -24,4 +24,9 @@
         <item>Relax</item>
         <item>Corteza</item>
     </string-array>
+    <string name="login_empty_field">Riempire tutti i campi</string>
+    <string name="login_unformed_instance">Formato URL non valido</string>
+    <string name="login_network_error">Controlla la tua connessione internet</string>
+    <string name="login_wrong_field">Credenziali non corrette</string>
+    <string name="login_success">Login effettuato con successo</string>
 </resources>