diff --git a/selfdrive/ui/qt/api.cc b/selfdrive/ui/qt/api.cc
index 1c997874e3..7c998d57a9 100644
--- a/selfdrive/ui/qt/api.cc
+++ b/selfdrive/ui/qt/api.cc
@@ -72,7 +72,7 @@ QString CommaApi::create_jwt(QVector<QPair<QString, QJsonValue>> payloads, int e
 }
 
 
-HttpRequest::HttpRequest(QObject *parent, QString requestURL, const QString &cache_key, bool create_jwt_) : cache_key(cache_key), create_jwt(create_jwt_), QObject(parent) {
+HttpRequest::HttpRequest(QObject *parent, const QString &requestURL, const QString &cache_key, bool create_jwt_) : cache_key(cache_key), create_jwt(create_jwt_), QObject(parent) {
   networkAccessManager = new QNetworkAccessManager(this);
   reply = NULL;
 
@@ -90,7 +90,7 @@ HttpRequest::HttpRequest(QObject *parent, QString requestURL, const QString &cac
   }
 }
 
-void HttpRequest::sendRequest(QString requestURL){
+void HttpRequest::sendRequest(const QString &requestURL){
   QString token;
   if(create_jwt) {
     token = CommaApi::create_jwt();
diff --git a/selfdrive/ui/qt/api.hpp b/selfdrive/ui/qt/api.hpp
index 347e12f784..0ec8f8b4b4 100644
--- a/selfdrive/ui/qt/api.hpp
+++ b/selfdrive/ui/qt/api.hpp
@@ -33,9 +33,9 @@ class HttpRequest : public QObject {
   Q_OBJECT
 
 public:
-  explicit HttpRequest(QObject* parent, QString requestURL, const QString &cache_key = "", bool create_jwt_ = true);
+  explicit HttpRequest(QObject* parent, const QString &requestURL, const QString &cache_key = "", bool create_jwt_ = true);
   QNetworkReply *reply;
-  void sendRequest(QString requestURL);
+  void sendRequest(const QString &requestURL);
 
 private:
   QNetworkAccessManager *networkAccessManager;
@@ -48,7 +48,7 @@ private slots:
   void requestFinished();
 
 signals:
-  void receivedResponse(QString response);
-  void failedResponse(QString errorString);
-  void timeoutResponse(QString errorString);
+  void receivedResponse(const QString &response);
+  void failedResponse(const QString &errorString);
+  void timeoutResponse(const QString &errorString);
 };
diff --git a/selfdrive/ui/qt/request_repeater.cc b/selfdrive/ui/qt/request_repeater.cc
index a0d4569954..651efd18bb 100644
--- a/selfdrive/ui/qt/request_repeater.cc
+++ b/selfdrive/ui/qt/request_repeater.cc
@@ -1,6 +1,6 @@
 #include "request_repeater.hpp"
 
-RequestRepeater::RequestRepeater(QObject *parent, QString requestURL, const QString &cacheKey,
+RequestRepeater::RequestRepeater(QObject *parent, const QString &requestURL, const QString &cacheKey,
                                  int period) : HttpRequest(parent, requestURL, cacheKey) {
   timer = new QTimer(this);
   timer->setTimerType(Qt::VeryCoarseTimer);
diff --git a/selfdrive/ui/qt/request_repeater.hpp b/selfdrive/ui/qt/request_repeater.hpp
index c0a0a787ec..ab4489c3dc 100644
--- a/selfdrive/ui/qt/request_repeater.hpp
+++ b/selfdrive/ui/qt/request_repeater.hpp
@@ -3,7 +3,7 @@
 
 class RequestRepeater : public HttpRequest {
 public:
-  RequestRepeater(QObject *parent, QString requestURL, const QString &cacheKey = "", int period = 0);
+  RequestRepeater(QObject *parent, const QString &requestURL, const QString &cacheKey = "", int period = 0);
 
 private:
   QTimer *timer;
diff --git a/selfdrive/ui/qt/widgets/drive_stats.cc b/selfdrive/ui/qt/widgets/drive_stats.cc
index 5db55d7b8f..6f810765a5 100644
--- a/selfdrive/ui/qt/widgets/drive_stats.cc
+++ b/selfdrive/ui/qt/widgets/drive_stats.cc
@@ -22,9 +22,8 @@ static QLayout* build_stat_layout(QLabel** metric, const QString& name) {
   return layout;
 }
 
-void DriveStats::parseResponse(QString response) {
-  response = response.trimmed();
-  QJsonDocument doc = QJsonDocument::fromJson(response.toUtf8());
+void DriveStats::parseResponse(const QString& response) {
+  QJsonDocument doc = QJsonDocument::fromJson(response.trimmed().toUtf8());
   if (doc.isNull()) {
     qDebug() << "JSON Parse failed on getting past drives statistics";
     return;
@@ -66,5 +65,5 @@ DriveStats::DriveStats(QWidget* parent) : QWidget(parent) {
   QString dongleId = QString::fromStdString(Params().get("DongleId"));
   QString url = "https://api.commadotai.com/v1.1/devices/" + dongleId + "/stats";
   RequestRepeater *repeater = new RequestRepeater(this, url, "ApiCache_DriveStats", 13);
-  QObject::connect(repeater, SIGNAL(receivedResponse(QString)), this, SLOT(parseResponse(QString)));
+  QObject::connect(repeater, &RequestRepeater::receivedResponse, this, &DriveStats::parseResponse);
 }
diff --git a/selfdrive/ui/qt/widgets/drive_stats.hpp b/selfdrive/ui/qt/widgets/drive_stats.hpp
index 64b93cfe73..d90e296b41 100644
--- a/selfdrive/ui/qt/widgets/drive_stats.hpp
+++ b/selfdrive/ui/qt/widgets/drive_stats.hpp
@@ -14,5 +14,5 @@ private:
   } all_, week_;
 
 private slots:
-  void parseResponse(QString response);
+  void parseResponse(const QString &response);
 };
diff --git a/selfdrive/ui/qt/widgets/setup.cc b/selfdrive/ui/qt/widgets/setup.cc
index a0480ed1a7..b5702c4c81 100644
--- a/selfdrive/ui/qt/widgets/setup.cc
+++ b/selfdrive/ui/qt/widgets/setup.cc
@@ -105,10 +105,10 @@ PrimeUserWidget::PrimeUserWidget(QWidget* parent) : QWidget(parent) {
 
   QString url = "https://api.commadotai.com/v1/devices/" + dongleId + "/owner";
   RequestRepeater *repeater = new RequestRepeater(this, url, "ApiCache_Owner", 6);
-  QObject::connect(repeater, SIGNAL(receivedResponse(QString)), this, SLOT(replyFinished(QString)));
+  QObject::connect(repeater, &RequestRepeater::receivedResponse, this, &PrimeUserWidget::replyFinished);
 }
 
-void PrimeUserWidget::replyFinished(QString response) {
+void PrimeUserWidget::replyFinished(const QString &response) {
   QJsonDocument doc = QJsonDocument::fromJson(response.toUtf8());
   if (doc.isNull()) {
     qDebug() << "JSON Parse failed on getting username and points";
@@ -238,12 +238,12 @@ SetupWidget::SetupWidget(QWidget* parent) : QFrame(parent) {
   QString url = "https://api.commadotai.com/v1.1/devices/" + dongleId + "/";
   RequestRepeater* repeater = new RequestRepeater(this, url, "ApiCache_Device", 5);
 
-  QObject::connect(repeater, SIGNAL(receivedResponse(QString)), this, SLOT(replyFinished(QString)));
-  QObject::connect(repeater, SIGNAL(failedResponse(QString)), this, SLOT(parseError(QString)));
+  QObject::connect(repeater, &RequestRepeater::receivedResponse, this, &SetupWidget::replyFinished);
+  QObject::connect(repeater, &RequestRepeater::failedResponse, this, &SetupWidget::parseError);
   hide(); // Only show when first request comes back
 }
 
-void SetupWidget::parseError(QString response) {
+void SetupWidget::parseError(const QString &response) {
   show();
   showQr = false;
   mainLayout->setCurrentIndex(0);
@@ -254,7 +254,7 @@ void SetupWidget::showQrCode(){
   mainLayout->setCurrentIndex(1);
 }
 
-void SetupWidget::replyFinished(QString response) {
+void SetupWidget::replyFinished(const QString &response) {
   show();
   QJsonDocument doc = QJsonDocument::fromJson(response.toUtf8());
   if (doc.isNull()) {
diff --git a/selfdrive/ui/qt/widgets/setup.hpp b/selfdrive/ui/qt/widgets/setup.hpp
index 0479db8f95..2c5f51bcc9 100644
--- a/selfdrive/ui/qt/widgets/setup.hpp
+++ b/selfdrive/ui/qt/widgets/setup.hpp
@@ -33,7 +33,7 @@ private:
   CommaApi* api;
 
 private slots:
-  void replyFinished(QString response);
+  void replyFinished(const QString &response);
 };
 
 class PrimeAdWidget : public QWidget {
@@ -56,7 +56,7 @@ private:
   bool showQr = false;
 
 private slots:
-  void parseError(QString response);
-  void replyFinished(QString response);
+  void parseError(const QString &response);
+  void replyFinished(const QString &response);
   void showQrCode();
 };