diff --git a/src/Mod/Part/Gui/DlgExportStep.cpp b/src/Mod/Part/Gui/DlgExportStep.cpp
index 90b5f6ec87..295b0a2709 100644
--- a/src/Mod/Part/Gui/DlgExportStep.cpp
+++ b/src/Mod/Part/Gui/DlgExportStep.cpp
@@ -25,8 +25,8 @@
 #ifndef _PreComp_
 # include <QCheckBox>
 # include <QDialogButtonBox>
-# include <QRegExp>
-# include <QRegExpValidator>
+# include <QRegularExpression>
+# include <QRegularExpressionValidator>
 # include <QVBoxLayout>
 # include <Interface_Static.hxx>
 #endif
@@ -148,13 +148,13 @@ DlgExportHeaderStep::DlgExportHeaderStep(QWidget* parent)
 
     ui->lineEditProduct->setReadOnly(true);
 
-    QRegExp rx;
+    QRegularExpression rx;
     rx.setPattern(QString::fromLatin1("[\\x00-\\x7F]+"));
-    QRegExpValidator* companyValidator = new QRegExpValidator(ui->lineEditCompany);
-    companyValidator->setRegExp(rx);
+    QRegularExpressionValidator* companyValidator = new QRegularExpressionValidator(ui->lineEditCompany);
+    companyValidator->setRegularExpression(rx);
     ui->lineEditCompany->setValidator(companyValidator);
-    QRegExpValidator* authorValidator = new QRegExpValidator(ui->lineEditAuthor);
-    authorValidator->setRegExp(rx);
+    QRegularExpressionValidator* authorValidator = new QRegularExpressionValidator(ui->lineEditAuthor);
+    authorValidator->setRegularExpression(rx);
     ui->lineEditAuthor->setValidator(authorValidator);
 }
 
diff --git a/src/Mod/Part/Gui/DlgSettingsGeneral.cpp b/src/Mod/Part/Gui/DlgSettingsGeneral.cpp
index 5866363b88..d90753b05e 100644
--- a/src/Mod/Part/Gui/DlgSettingsGeneral.cpp
+++ b/src/Mod/Part/Gui/DlgSettingsGeneral.cpp
@@ -23,8 +23,8 @@
 #include "PreCompiled.h"
 #ifndef _PreComp_
 # include <QButtonGroup>
-# include <QRegExp>
-# include <QRegExpValidator>
+# include <QRegularExpression>
+# include <QRegularExpressionValidator>
 # include <QVBoxLayout>
 # include <Interface_Static.hxx>
 #endif
@@ -98,13 +98,13 @@ DlgImportExportIges::DlgImportExportIges(QWidget* parent)
     bg->addButton(ui->radioButtonBRepOff, 0);
     bg->addButton(ui->radioButtonBRepOn, 1);
 
-    QRegExp rx;
+    QRegularExpression rx;
     rx.setPattern(QString::fromLatin1("[\\x00-\\x7F]+"));
-    QRegExpValidator* companyValidator = new QRegExpValidator(ui->lineEditCompany);
-    companyValidator->setRegExp(rx);
+    QRegularExpressionValidator* companyValidator = new QRegularExpressionValidator(ui->lineEditCompany);
+    companyValidator->setRegularExpression(rx);
     ui->lineEditCompany->setValidator(companyValidator);
-    QRegExpValidator* authorValidator = new QRegExpValidator(ui->lineEditAuthor);
-    authorValidator->setRegExp(rx);
+    QRegularExpressionValidator* authorValidator = new QRegularExpressionValidator(ui->lineEditAuthor);
+    authorValidator->setRegularExpression(rx);
     ui->lineEditAuthor->setValidator(authorValidator);
 }
 
diff --git a/src/Mod/Part/Gui/Mirroring.cpp b/src/Mod/Part/Gui/Mirroring.cpp
index fbf77c417e..2b0e3fe108 100644
--- a/src/Mod/Part/Gui/Mirroring.cpp
+++ b/src/Mod/Part/Gui/Mirroring.cpp
@@ -31,7 +31,7 @@
 
 # include <cfloat>
 # include <QMessageBox>
-# include <QRegExp>
+# include <QRegularExpression>
 # include <QTreeWidget>
 #endif
 
@@ -142,7 +142,7 @@ bool Mirroring::accept()
     activeDoc->openTransaction("Mirroring");
 
     QString shape, label;
-    QRegExp rx(QString::fromLatin1(" \\(Mirror #\\d+\\)$"));
+    QRegularExpression rx(QString::fromLatin1(" \\(Mirror #\\d+\\)$"));
     QList<QTreeWidgetItem *> items = ui->shapes->selectedItems();
     float normx=0, normy=0, normz=0;
     int index = ui->comboBox->currentIndex();
diff --git a/src/Mod/Part/Gui/TaskAttacher.cpp b/src/Mod/Part/Gui/TaskAttacher.cpp
index e53a416f62..40cab985da 100644
--- a/src/Mod/Part/Gui/TaskAttacher.cpp
+++ b/src/Mod/Part/Gui/TaskAttacher.cpp
@@ -26,7 +26,8 @@
 #ifndef _PreComp_
 # include <sstream>
 # include <QMessageBox>
-# include <QRegExp>
+# include <QRegularExpression>
+# include <QRegularExpressionMatch>
 # include <Standard_Failure.hxx>
 #endif
 
@@ -616,34 +617,43 @@ void TaskAttacher::onRefName(const QString& text, unsigned idx)
     } else {
         // TODO: check validity of the text that was entered: Does subElement actually reference to an element on the obj?
 
-        // We must expect that "text" is the translation of "Face", "Edge" or "Vertex" followed by an ID.
-        QRegExp rx;
-        std::stringstream ss;
+        auto getSubshapeName = [](const QString& part) -> std::string {
+            // We must expect that "text" is the translation of "Face", "Edge" or "Vertex" followed by an ID.
+            QRegularExpression rx;
+            QRegularExpressionMatch match;
+            std::stringstream ss;
 
-        rx.setPattern(QString::fromLatin1("^") + tr("Face") + QString::fromLatin1("(\\d+)$"));
-        if (parts[1].indexOf(rx) >= 0) {
-            int faceId = rx.cap(1).toInt();
-            ss << "Face" << faceId;
-        } else {
-            rx.setPattern(QString::fromLatin1("^") + tr("Edge") + QString::fromLatin1("(\\d+)$"));
-            if (parts[1].indexOf(rx) >= 0) {
-                int lineId = rx.cap(1).toInt();
-                ss << "Edge" << lineId;
-            } else {
-                rx.setPattern(QString::fromLatin1("^") + tr("Vertex") + QString::fromLatin1("(\\d+)$"));
-                if (parts[1].indexOf(rx) >= 0) {
-                    int vertexId = rx.cap(1).toInt();
-                    ss << "Vertex" << vertexId;
-                } else {
-                    //none of Edge/Vertex/Face. May be empty string.
-                    //Feed in whatever user supplied, even if invalid.
-                    ss << parts[1].toLatin1().constData();
-                }
+            rx.setPattern(QString::fromLatin1("^") + tr("Face") + QString::fromLatin1("(\\d+)$"));
+            if (part.indexOf(rx, 0, &match) >= 0) {
+                int faceId = match.captured(1).toInt();
+                ss << "Face" << faceId;
+                return ss.str();
             }
-        }
 
-        line->setProperty("RefName", QByteArray(ss.str().c_str()));
-        subElement = ss.str();
+            rx.setPattern(QString::fromLatin1("^") + tr("Edge") + QString::fromLatin1("(\\d+)$"));
+            if (part.indexOf(rx, 0, &match) >= 0) {
+                int lineId = match.captured(1).toInt();
+                ss << "Edge" << lineId;
+                return ss.str();
+            }
+
+            rx.setPattern(QString::fromLatin1("^") + tr("Vertex") + QString::fromLatin1("(\\d+)$"));
+            if (part.indexOf(rx, 0, &match) >= 0) {
+                int vertexId = match.captured(1).toInt();
+                ss << "Vertex" << vertexId;
+                return ss.str();
+            }
+
+            //none of Edge/Vertex/Face. May be empty string.
+            //Feed in whatever user supplied, even if invalid.
+            ss << part.toLatin1().constData();
+            return ss.str();
+        };
+
+        auto name = getSubshapeName(parts[1]);
+
+        line->setProperty("RefName", QByteArray(name.c_str()));
+        subElement = name;
     }
 
     Part::AttachExtension* pcAttach = ViewProvider->getObject()->getExtensionByType<Part::AttachExtension>();
diff --git a/src/Mod/PartDesign/Gui/TaskSketchBasedParameters.cpp b/src/Mod/PartDesign/Gui/TaskSketchBasedParameters.cpp
index cd1bc567fb..668fc3663f 100644
--- a/src/Mod/PartDesign/Gui/TaskSketchBasedParameters.cpp
+++ b/src/Mod/PartDesign/Gui/TaskSketchBasedParameters.cpp
@@ -25,7 +25,8 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
-# include <QRegExp>
+# include <QRegularExpression>
+# include <QRegularExpressionMatch>
 # include <QTextStream>
 #endif
 
@@ -158,16 +159,17 @@ QVariant TaskSketchBasedParameters::setUpToFace(const QString& text)
         QString name;
         QTextStream str(&name);
         str << "^" << tr("Face") << "(\\d+)$";
-        QRegExp rx(name);
-        if (parts[1].indexOf(rx) < 0) {
+        QRegularExpression rx(name);
+        QRegularExpressionMatch match;
+        if (parts[1].indexOf(rx, 0, &match) < 0) {
             return QVariant();
         }
 
-        int faceId = rx.cap(1).toInt();
+        int faceId = match.captured(1).toInt();
         std::stringstream ss;
         ss << "Face" << faceId;
 
-        std::vector<std::string> upToFaces(1,ss.str());
+        std::vector<std::string> upToFaces(1, ss.str());
         PartDesign::ProfileBased* pcSketchBased = static_cast<PartDesign::ProfileBased*>(vp->getObject());
         pcSketchBased->UpToFace.setValue(obj, upToFaces);
         recomputeFeature();
diff --git a/src/Mod/Path/Gui/TaskDlgPathCompound.cpp b/src/Mod/Path/Gui/TaskDlgPathCompound.cpp
index 66d1dc282b..a0b9f7aeaf 100644
--- a/src/Mod/Path/Gui/TaskDlgPathCompound.cpp
+++ b/src/Mod/Path/Gui/TaskDlgPathCompound.cpp
@@ -24,6 +24,7 @@
 #include "PreCompiled.h"
 
 #ifndef _PreComp_
+# include <QRegularExpression>
 #endif
 
 #include "TaskDlgPathCompound.h"
@@ -86,7 +87,7 @@ std::vector<std::string> TaskWidgetPathCompound::getList() const {
         QListWidgetItem* item = ui->PathsList->item(i);
         QString name = item->text();
         QStringList result;
-        result = name.split(QRegExp(QString::fromLatin1("\\s+")));
+        result = name.split(QRegularExpression(QString::fromLatin1("\\s+")));
         std::cout << result[0].toStdString() << std::endl;
         names.push_back(result[0].toStdString());
     }
diff --git a/src/Mod/Raytracing/Gui/PovrayHighlighter.cpp b/src/Mod/Raytracing/Gui/PovrayHighlighter.cpp
index c0c30b261c..d0eb7ceeca 100644
--- a/src/Mod/Raytracing/Gui/PovrayHighlighter.cpp
+++ b/src/Mod/Raytracing/Gui/PovrayHighlighter.cpp
@@ -23,7 +23,8 @@
 
 #include "PreCompiled.h"
 #ifndef _PreComp_
-# include <QRegExp>
+# include <QRegularExpression>
+# include <QRegularExpressionMatch>
 #endif
 
 #include "PovrayHighlighter.h"
@@ -95,12 +96,13 @@ void PovrayHighlighter::highlightBlock(const QString &text)
                 state = InsideCStyleComment;
             }
             else if (text.mid(i,1) == QLatin1String("#")) {
-                QRegExp rx(QLatin1String("#\\s*(\\w*)"));
-                int pos = text.indexOf(rx, i);
-                if (pos != -1) {
-                    if (d->keywords.contains(rx.cap(1)) != 0)
-                        setFormat(i, rx.matchedLength(), this->colorByType(SyntaxHighlighter::Keyword));
-                    i += rx.matchedLength();
+                QRegularExpression rx(QLatin1String("#\\s*(\\w*)"));
+                QRegularExpressionMatch match;
+                text.indexOf(rx, i, &match);
+                if (match.hasMatch()) {
+                    if (d->keywords.contains(match.captured(1)) != 0)
+                        setFormat(i, match.capturedLength(), this->colorByType(SyntaxHighlighter::Keyword));
+                    i += match.capturedLength();
                 }
             }
             else if (text[i] == QLatin1Char('"')) {
diff --git a/src/Mod/Sketcher/Gui/EditModeConstraintCoinManager.cpp b/src/Mod/Sketcher/Gui/EditModeConstraintCoinManager.cpp
index 0a3953d096..4ac6e54432 100644
--- a/src/Mod/Sketcher/Gui/EditModeConstraintCoinManager.cpp
+++ b/src/Mod/Sketcher/Gui/EditModeConstraintCoinManager.cpp
@@ -53,6 +53,8 @@
 # include <Inventor/SbVec3f.h>
 # include <Inventor/SbImage.h>
 
+# include <QRegularExpression>
+
 # include <memory>
 #endif  // #ifndef _PreComp_
 
@@ -1669,7 +1671,7 @@ QString EditModeConstraintCoinManager::getPresentationString(const Constraint *c
             if (QString::compare(baseUnitStr, unitStr)==0)
             {
                 // Example code from: Mod/TechDraw/App/DrawViewDimension.cpp:372
-                QRegExp rxUnits(QString::fromUtf8(" \\D*$"));  //space + any non digits at end of string
+                QRegularExpression rxUnits(QString::fromUtf8(" \\D*$"));  //space + any non digits at end of string
                 valueStr.remove(rxUnits);                      //getUserString(defaultDecimals) without units
             }
         }
diff --git a/src/Mod/Sketcher/Gui/TaskSketcherConstraints.cpp b/src/Mod/Sketcher/Gui/TaskSketcherConstraints.cpp
index 82e5ef65d4..df2a44c8f8 100644
--- a/src/Mod/Sketcher/Gui/TaskSketcherConstraints.cpp
+++ b/src/Mod/Sketcher/Gui/TaskSketcherConstraints.cpp
@@ -27,7 +27,8 @@
 # include <cmath>
 # include <QContextMenuEvent>
 # include <QMenu>
-# include <QRegExp>
+# include <QRegularExpression>
+# include <QRegularExpressionMatch>
 # include <QString>
 # include <QMessageBox>
 # include <QStyledItemDelegate>
@@ -976,12 +977,13 @@ void TaskSketcherConstraints::onSelectionChanged(const Gui::SelectionChanges& ms
         if (strcmp(msg.pDocName,sketchView->getSketchObject()->getDocument()->getName())==0 &&
             strcmp(msg.pObjectName,sketchView->getSketchObject()->getNameInDocument())== 0) {
             if (msg.pSubName) {
-                QRegExp rx(QString::fromLatin1("^Constraint(\\d+)$"));
+                QRegularExpression rx(QString::fromLatin1("^Constraint(\\d+)$"));
+                QRegularExpressionMatch match;
                 QString expr = QString::fromLatin1(msg.pSubName);
-                int pos = expr.indexOf(rx);
-                if (pos > -1) { // is a constraint
+                expr.indexOf(rx, 0, &match);
+                if (match.hasMatch()) { // is a constraint
                     bool ok;
-                    int ConstrId = rx.cap(1).toInt(&ok) - 1;
+                    int ConstrId = match.captured(1).toInt(&ok) - 1;
                     if (ok) {
                         int countItems = ui->listWidgetConstraints->count();
                         for (int i=0; i < countItems; i++) {
@@ -1025,25 +1027,26 @@ void TaskSketcherConstraints::onSelectionChanged(const Gui::SelectionChanges& ms
 
 void TaskSketcherConstraints::getSelectionGeoId(QString expr, int & geoid, Sketcher::PointPos & pointpos)
 {
-    QRegExp rxEdge(QString::fromLatin1("^Edge(\\d+)$"));
-    int pos = expr.indexOf(rxEdge);
+    QRegularExpression rxEdge(QString::fromLatin1("^Edge(\\d+)$"));
+    QRegularExpressionMatch match;
+    expr.indexOf(rxEdge, 0, &match);
     geoid = Sketcher::GeoEnum::GeoUndef;
     pointpos = Sketcher::PointPos::none;
 
-    if (pos > -1) {
+    if (match.hasMatch()) {
         bool ok;
-        int edgeId = rxEdge.cap(1).toInt(&ok) - 1;
+        int edgeId = match.captured(1).toInt(&ok) - 1;
         if (ok) {
             geoid = edgeId;
         }
     }
     else {
-        QRegExp rxVertex(QString::fromLatin1("^Vertex(\\d+)$"));
-        pos = expr.indexOf(rxVertex);
+        QRegularExpression rxVertex(QString::fromLatin1("^Vertex(\\d+)$"));
+        expr.indexOf(rxVertex, 0, &match);
 
-        if (pos > -1) {
+        if (match.hasMatch()) {
             bool ok;
-            int vertexId = rxVertex.cap(1).toInt(&ok) - 1;
+            int vertexId = match.captured(1).toInt(&ok) - 1;
             if (ok) {
                 const Sketcher::SketchObject * sketch = sketchView->getSketchObject();
                 sketch->getGeoVertexIndex(vertexId, geoid, pointpos);
diff --git a/src/Mod/Sketcher/Gui/TaskSketcherElements.cpp b/src/Mod/Sketcher/Gui/TaskSketcherElements.cpp
index 04cf55605c..b10ed786eb 100644
--- a/src/Mod/Sketcher/Gui/TaskSketcherElements.cpp
+++ b/src/Mod/Sketcher/Gui/TaskSketcherElements.cpp
@@ -26,7 +26,8 @@
 #ifndef _PreComp_
 # include <QContextMenuEvent>
 # include <QMenu>
-# include <QRegExp>
+# include <QRegularExpression>
+# include <QRegularExpressionMatch>
 # include <QShortcut>
 # include <QString>
 # include <QImage>
@@ -360,11 +361,12 @@ void TaskSketcherElements::onSelectionChanged(const Gui::SelectionChanges& msg)
                 std::string shapetype(msg.pSubName);
                 // if-else edge vertex
                 if (shapetype.size() > 4 && shapetype.substr(0,4) == "Edge") {
-                    QRegExp rx(QString::fromLatin1("^Edge(\\d+)$"));
-                    int pos = expr.indexOf(rx);
-                    if (pos > -1) {
+                    QRegularExpression rx(QString::fromLatin1("^Edge(\\d+)$"));
+                    QRegularExpressionMatch match;
+                    expr.indexOf(rx, 0, &match);
+                    if (match.hasMatch()) {
                         bool ok;
-                        int ElementId = rx.cap(1).toInt(&ok) - 1;
+                        int ElementId = match.captured(1).toInt(&ok) - 1;
                         if (ok) {
                             int countItems = ui->listWidgetElements->count();
                             for (int i=0; i < countItems; i++) {
@@ -379,11 +381,12 @@ void TaskSketcherElements::onSelectionChanged(const Gui::SelectionChanges& msg)
                     }
                 }
                 else if (shapetype.size() > 6 && shapetype.substr(0,6) == "Vertex"){
-                    QRegExp rx(QString::fromLatin1("^Vertex(\\d+)$"));
-                    int pos = expr.indexOf(rx);
-                    if (pos > -1) {
+                    QRegularExpression rx(QString::fromLatin1("^Vertex(\\d+)$"));
+                    QRegularExpressionMatch match;
+                    expr.indexOf(rx, 0, &match);
+                    if (match.hasMatch()) {
                         bool ok;
-                        int ElementId = rx.cap(1).toInt(&ok) - 1;
+                        int ElementId = match.captured(1).toInt(&ok) - 1;
                         if (ok) {
                             // Get the GeoID&Pos
                             int GeoId;
diff --git a/src/Mod/TechDraw/App/DrawUtil.cpp b/src/Mod/TechDraw/App/DrawUtil.cpp
index cd1ff4feeb..ea05e0458a 100644
--- a/src/Mod/TechDraw/App/DrawUtil.cpp
+++ b/src/Mod/TechDraw/App/DrawUtil.cpp
@@ -32,7 +32,6 @@
 #include <boost/regex.hpp>
 #include <QString>
 #include <QStringList>
-#include <QRegExp>
 #include <QChar>
 #include <QPointF>
 
diff --git a/src/Mod/TechDraw/Gui/Command.cpp b/src/Mod/TechDraw/Gui/Command.cpp
index 8c9e2a8ae6..07f5df34d8 100644
--- a/src/Mod/TechDraw/Gui/Command.cpp
+++ b/src/Mod/TechDraw/Gui/Command.cpp
@@ -29,7 +29,6 @@
 #include <QGraphicsView>
 #include <QMessageBox>
 #include <QPainter>
-#include <QRegExp>
 #include <QStringBuilder>
 #include <QSvgGenerator>
 #include <QSvgRenderer>
diff --git a/src/Mod/TechDraw/Gui/DrawGuiUtil.cpp b/src/Mod/TechDraw/Gui/DrawGuiUtil.cpp
index ec7c7179b9..f75f97a614 100644
--- a/src/Mod/TechDraw/Gui/DrawGuiUtil.cpp
+++ b/src/Mod/TechDraw/Gui/DrawGuiUtil.cpp
@@ -31,7 +31,6 @@
 # include <QComboBox>
 # include <QString>
 # include <QStringList>
-# include <QRegExp>
 # include <QMessageBox>
 # include <QRectF>
 # include <QPointF>
diff --git a/src/Mod/Web/Gui/BrowserView.cpp b/src/Mod/Web/Gui/BrowserView.cpp
index 40ef609db4..3b41889264 100644
--- a/src/Mod/Web/Gui/BrowserView.cpp
+++ b/src/Mod/Web/Gui/BrowserView.cpp
@@ -32,7 +32,8 @@
 # include <QMessageBox>
 # include <QMouseEvent>
 # include <QNetworkRequest>
-# include <QRegExp>
+# include <QRegularExpression>
+# include <QRegularExpressionMatch>
 # include <QScreen>
 # include <QSignalMapper>
 # include <QStatusBar>
@@ -97,11 +98,12 @@ public:
         if (info.navigationType() == QWebEngineUrlRequestInfo::NavigationTypeLink) {
             // wash out windows file:///C:/something ->file://C:/something
             QUrl url = info.requestUrl();
-            QRegExp re(QLatin1String("^/([a-zA-Z]\\:.*)")); // match & catch drive letter forward
+            QRegularExpression re(QLatin1String("^/([a-zA-Z]\\:.*)")); // match & catch drive letter forward
+            QRegularExpressionMatch match = re.match(url.path());
 
-            if (url.host().isEmpty() && url.isLocalFile() && re.exactMatch(url.path()))
+            if (url.host().isEmpty() && url.isLocalFile() && match.hasMatch())
                 // clip / in file urs ie /C:/something -> C:/something
-                url.setPath(re.cap(1));
+                url.setPath(match.captured(1));
 
             // invoke thread safe.
             QMetaObject::invokeMethod(m_parent, "urlFilter", Q_ARG(QUrl, url));