diff --git a/src/ESPUI.cpp b/src/ESPUI.cpp
index 858d291..497937e 100644
--- a/src/ESPUI.cpp
+++ b/src/ESPUI.cpp
@@ -500,7 +500,7 @@ void onWsEvent(AsyncWebSocket *server, AsyncWebSocketClient *client, AwsEventTyp
   }
 }
 
-uint16_t ESPUIClass::addControl(ControlType type, const char *label, String value, ControlColor color, uint16_t parentControl,
+uint16_t ESPUIClass::addControl(ControlType type, const char *label, const String& value, ControlColor color, uint16_t parentControl,
                                 void (*callback)(Control *, int))
 {
   Control *control = new Control(type, label, callback, value, color, parentControl);
@@ -571,7 +571,7 @@ bool ESPUIClass::removeControl(uint16_t id, bool force_reload_ui)
   return false;
 }
 
-uint16_t ESPUIClass::label(const char *label, ControlColor color, String value) { return addControl(ControlType::Label, label, value, color); }
+uint16_t ESPUIClass::label(const char *label, ControlColor color, const String& value) { return addControl(ControlType::Label, label, value, color); }
 
 uint16_t ESPUIClass::graph(const char *label, ControlColor color) { return addControl(ControlType::Graph, label, "", color); }
 
@@ -584,7 +584,7 @@ uint16_t ESPUIClass::slider(const char *label, void (*callback)(Control *, int),
   return sliderId;
 }
 
-uint16_t ESPUIClass::button(const char *label, void (*callback)(Control *, int), ControlColor color, String value)
+uint16_t ESPUIClass::button(const char *label, void (*callback)(Control *, int), ControlColor color, const String& value)
 {
   return addControl(ControlType::Button, label, value, color, Control::noParent, callback);
 }
@@ -624,7 +624,7 @@ uint16_t ESPUIClass::accelerometer(const char *label, void (*callback)(Control *
   return addControl(ControlType::Accel, label, "", color, Control::noParent, callback);
 }
 
-uint16_t ESPUIClass::text(const char *label, void (*callback)(Control *, int), ControlColor color, String value)
+uint16_t ESPUIClass::text(const char *label, void (*callback)(Control *, int), ControlColor color, const String& value)
 {
   return addControl(ControlType::Text, label, value, color, Control::noParent, callback);
 }
@@ -713,7 +713,7 @@ void ESPUIClass::updateControl(uint16_t id, int clientId)
   updateControl(control, clientId);
 }
 
-void ESPUIClass::updateControlValue(Control *control, String value, int clientId)
+void ESPUIClass::updateControlValue(Control *control, const String& value, int clientId)
 {
   if (!control)
   {
@@ -724,7 +724,7 @@ void ESPUIClass::updateControlValue(Control *control, String value, int clientId
   updateControl(control, clientId);
 }
 
-void ESPUIClass::updateControlValue(uint16_t id, String value, int clientId)
+void ESPUIClass::updateControlValue(uint16_t id, const String& value, int clientId)
 {
   Control *control = getControl(id);
 
@@ -740,9 +740,9 @@ void ESPUIClass::updateControlValue(uint16_t id, String value, int clientId)
   updateControlValue(control, value, clientId);
 }
 
-void ESPUIClass::print(uint16_t id, String value) { updateControlValue(id, value); }
+void ESPUIClass::print(uint16_t id, const String& value) { updateControlValue(id, value); }
 
-void ESPUIClass::updateLabel(uint16_t id, String value) { updateControlValue(id, value); }
+void ESPUIClass::updateLabel(uint16_t id, const String& value) { updateControlValue(id, value); }
 
 void ESPUIClass::updateSlider(uint16_t id, int nValue, int clientId) { updateControlValue(id, String(nValue), clientId); }
 
@@ -750,9 +750,9 @@ void ESPUIClass::updateSwitcher(uint16_t id, bool nValue, int clientId) { update
 
 void ESPUIClass::updateNumber(uint16_t id, int number, int clientId) { updateControlValue(id, String(number), clientId); }
 
-void ESPUIClass::updateText(uint16_t id, String text, int clientId) { updateControlValue(id, text, clientId); }
+void ESPUIClass::updateText(uint16_t id, const String& text, int clientId) { updateControlValue(id, text, clientId); }
 
-void ESPUIClass::updateSelect(uint16_t id, String text, int clientId) { updateControlValue(id, text, clientId); }
+void ESPUIClass::updateSelect(uint16_t id, const String& text, int clientId) { updateControlValue(id, text, clientId); }
 
 void ESPUIClass::updateGauge(uint16_t id, int number, int clientId) { updateControlValue(id, String(number), clientId); }
 
diff --git a/src/ESPUI.h b/src/ESPUI.h
index a491330..0487439 100644
--- a/src/ESPUI.h
+++ b/src/ESPUI.h
@@ -140,7 +140,7 @@ public:
 
   static constexpr uint16_t noParent = 0xffff;
 
-  Control(ControlType type, const char *label, void (*callback)(Control *, int), String value, ControlColor color,
+  Control(ControlType type, const char *label, void (*callback)(Control *, int), const String& value, ControlColor color,
           uint16_t parentControl = Control::noParent)
       : type(type), label(label), callback(callback), value(value), color(color), parentControl(parentControl), next(nullptr)
   {
@@ -206,11 +206,11 @@ public:
   void prepareFileSystem(); // Initially preps the filesystem and loads a lot of stuff into SPIFFS
   void list();              // Lists SPIFFS directory
 
-  uint16_t addControl(ControlType type, const char *label, String value = String(""), ControlColor color = ControlColor::Turquoise, uint16_t parentControl = Control::noParent, void (*callback)(Control *, int) = nullptr);
+  uint16_t addControl(ControlType type, const char *label, const String& value = String(""), ControlColor color = ControlColor::Turquoise, uint16_t parentControl = Control::noParent, void (*callback)(Control *, int) = nullptr);
   bool removeControl(uint16_t id, bool force_reload_ui = false);
 
   // create Elements
-  uint16_t button(const char *label, void (*callback)(Control *, int), ControlColor color, String value = "");         // Create Event Button
+  uint16_t button(const char *label, void (*callback)(Control *, int), ControlColor color, const String& value = "");         // Create Event Button
   uint16_t switcher(const char *label, void (*callback)(Control *, int), ControlColor color, bool startState = false); // Create Toggle Button
   uint16_t pad(const char *label, void (*callback)(Control *, int), ControlColor color);                               // Create Pad Control
   uint16_t padWithCenter(const char *label, void (*callback)(Control *, int), ControlColor color);                     // Create Pad Control with Centerbutton
@@ -219,10 +219,10 @@ public:
                   int max = 100); // Create Slider Control
   uint16_t number(const char *label, void (*callback)(Control *, int), ControlColor color, int value, int min = 0,
                   int max = 100);                                                                            // Create a Number Input Control
-  uint16_t text(const char *label, void (*callback)(Control *, int), ControlColor color, String value = ""); // Create a Text Input Control
+  uint16_t text(const char *label, void (*callback)(Control *, int), ControlColor color, const String& value = ""); // Create a Text Input Control
 
   // Output only
-  uint16_t label(const char *label, ControlColor color, String value = "");                     // Create Label
+  uint16_t label(const char *label, ControlColor color, const String& value = "");                     // Create Label
   uint16_t graph(const char *label, ControlColor color);                                        // Create Graph display
   uint16_t gauge(const char *label, ControlColor color, int value, int min = 0, int max = 100); // Create Gauge display
 
@@ -234,19 +234,19 @@ public:
   Control *getControl(uint16_t id);
 
   // Update Elements
-  void updateControlValue(uint16_t id, String value, int clientId = -1);
-  void updateControlValue(Control *control, String value, int clientId = -1);
+  void updateControlValue(uint16_t id, const String& value, int clientId = -1);
+  void updateControlValue(Control *control, const String& value, int clientId = -1);
 
   void updateControl(uint16_t id, int clientId = -1);
   void updateControl(Control *control, int clientId = -1);
 
-  void print(uint16_t id, String value);
-  void updateLabel(uint16_t id, String value);
+  void print(uint16_t id, const String& value);
+  void updateLabel(uint16_t id, const String& value);
   void updateSwitcher(uint16_t id, bool nValue, int clientId = -1);
   void updateSlider(uint16_t id, int nValue, int clientId = -1);
   void updateNumber(uint16_t id, int nValue, int clientId = -1);
-  void updateText(uint16_t id, String nValue, int clientId = -1);
-  void updateSelect(uint16_t id, String nValue, int clientId = -1);
+  void updateText(uint16_t id, const String& nValue, int clientId = -1);
+  void updateSelect(uint16_t id, const String& nValue, int clientId = -1);
   void updateGauge(uint16_t id, int number, int clientId);
 
   void clearGraph(uint16_t id, int clientId = -1);