diff --git a/qmake/generators/xmloutput.cpp b/qmake/generators/xmloutput.cpp
index c43f8d810b1..78d6518dabc 100644
--- a/qmake/generators/xmloutput.cpp
+++ b/qmake/generators/xmloutput.cpp
@@ -103,7 +103,7 @@ void XmlOutput::decreaseIndent()
 
 QString XmlOutput::doConversion(const QString &text)
 {
-    if (!text.count())
+    if (!text.size())
         return QString();
     else if (conversion == NoConversion)
         return text;
@@ -112,10 +112,10 @@ QString XmlOutput::doConversion(const QString &text)
     if (conversion == XMLConversion) {
 
         // this is a way to escape characters that shouldn't be converted
-        for (int i=0; i<text.count(); ++i) {
+        for (int i=0; i<text.size(); ++i) {
             const QChar c = text.at(i);
             if (c == QLatin1Char('&')) {
-                if ( (i + 7) < text.count() &&
+                if ( (i + 7) < text.size() &&
                     text.at(i + 1) == QLatin1Char('#') &&
                     text.at(i + 2) == QLatin1Char('x') &&
                     text.at(i + 7) == QLatin1Char(';') ) {
@@ -184,9 +184,9 @@ XmlOutput& XmlOutput::operator<<(const xml_output& o)
         addRaw(QString("\n%1<Import %2=\"%3\" />").arg(currentIndent).arg(o.xo_text).arg(o.xo_value));
         break;
     case tCloseTag:
-        if (o.xo_value.count())
+        if (o.xo_value.size())
             closeAll();
-        else if (o.xo_text.count())
+        else if (o.xo_text.size())
             closeTo(o.xo_text);
         else
             closeTag();
@@ -201,7 +201,7 @@ XmlOutput& XmlOutput::operator<<(const xml_output& o)
         {
             // Special case to be able to close tag in normal
             // way ("</tag>", not "/>") without using addRaw()..
-            if (!o.xo_text.count()) {
+            if (!o.xo_text.size()) {
                 closeOpen();
                 break;
             }
@@ -230,14 +230,14 @@ XmlOutput& XmlOutput::operator<<(const xml_output& o)
 // Output functions ----------------------------------------------------------
 void XmlOutput::newTag(const QString &tag)
 {
-    Q_ASSERT_X(tag.count(), "XmlOutput", "Cannot open an empty tag");
+    Q_ASSERT_X(tag.size(), "XmlOutput", "Cannot open an empty tag");
     newTagOpen(tag);
     closeOpen();
 }
 
 void XmlOutput::newTagOpen(const QString &tag)
 {
-    Q_ASSERT_X(tag.count(), "XmlOutput", "Cannot open an empty tag");
+    Q_ASSERT_X(tag.size(), "XmlOutput", "Cannot open an empty tag");
     closeOpen();
 
     if (format == NewLine)
diff --git a/src/corelib/io/qloggingregistry.cpp b/src/corelib/io/qloggingregistry.cpp
index 73b98190a71..52d76d689a1 100644
--- a/src/corelib/io/qloggingregistry.cpp
+++ b/src/corelib/io/qloggingregistry.cpp
@@ -112,7 +112,7 @@ int QLoggingRule::pass(QLatin1String cat, QtMsgType msgType) const
                 return (enabled ? 1 : -1);
         } else if (flags == RightFilter) {
             // matches right
-            if (idx == (cat.size() - category.count()))
+            if (idx == (cat.size() - category.size()))
                 return (enabled ? 1 : -1);
         }
     }
diff --git a/src/corelib/text/qbytearray.cpp b/src/corelib/text/qbytearray.cpp
index 62c52bbca14..a3254c9a727 100644
--- a/src/corelib/text/qbytearray.cpp
+++ b/src/corelib/text/qbytearray.cpp
@@ -2659,12 +2659,14 @@ qsizetype QByteArray::count(char ch) const
     return static_cast<int>(countCharHelper(*this, ch));
 }
 
+#if QT_DEPRECATED_SINCE(6, 4)
 /*! \fn qsizetype QByteArray::count() const
-
+    \deprecated [6.4] Use size() or length() instead.
     \overload
 
     Same as size().
 */
+#endif
 
 /*!
     \fn int QByteArray::compare(QByteArrayView bv, Qt::CaseSensitivity cs = Qt::CaseSensitive) const
@@ -4481,7 +4483,7 @@ static void q_fromPercentEncoding(QByteArray *ba, char percent)
     const char *inputPtr = data;
 
     qsizetype i = 0;
-    qsizetype len = ba->count();
+    qsizetype len = ba->size();
     qsizetype outlen = 0;
     int a, b;
     char c;
@@ -4584,7 +4586,7 @@ static void q_toPercentEncoding(QByteArray *ba, const char *dontEncode, const ch
         return;
 
     QByteArray input = *ba;
-    qsizetype len = input.count();
+    qsizetype len = input.size();
     const char *inputData = input.constData();
     char *output = nullptr;
     qsizetype length = 0;
diff --git a/src/corelib/text/qbytearray.h b/src/corelib/text/qbytearray.h
index d3b3c3ca6ec..bacc023cdfd 100644
--- a/src/corelib/text/qbytearray.h
+++ b/src/corelib/text/qbytearray.h
@@ -468,7 +468,10 @@ public:
     inline std::string toStdString() const;
 
     inline qsizetype size() const noexcept { return d->size; }
+#if QT_DEPRECATED_SINCE(6, 4)
+    QT_DEPRECATED_VERSION_X_6_4("Use size() or length() instead.")
     inline qsizetype count() const noexcept { return size(); }
+#endif
     inline qsizetype length() const noexcept { return size(); }
     bool isNull() const noexcept;
 
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp
index c0fed806a6d..1464763b058 100644
--- a/src/corelib/text/qstring.cpp
+++ b/src/corelib/text/qstring.cpp
@@ -4671,13 +4671,14 @@ qsizetype QString::count(const QRegularExpression &re) const
 }
 #endif // QT_CONFIG(regularexpression)
 
+#if QT_DEPRECATED_SINCE(6, 4)
 /*! \fn qsizetype QString::count() const
-
+    \deprecated [6.4] Use size() or length() instead.
     \overload count()
 
     Same as size().
 */
-
+#endif
 
 /*!
     \enum QString::SectionFlag
diff --git a/src/corelib/text/qstring.h b/src/corelib/text/qstring.h
index 7b494ec2e3b..b30f4ac981b 100644
--- a/src/corelib/text/qstring.h
+++ b/src/corelib/text/qstring.h
@@ -466,7 +466,10 @@ public:
     QT_MOVE_ASSIGNMENT_OPERATOR_IMPL_VIA_PURE_SWAP(QString)
     void swap(QString &other) noexcept { d.swap(other.d); }
     inline qsizetype size() const { return d.size; }
+#if QT_DEPRECATED_SINCE(6, 4)
+    QT_DEPRECATED_VERSION_X_6_4("Use size() or length() instead.")
     inline qsizetype count() const { return d.size; }
+#endif
     inline qsizetype length() const { return d.size; }
     inline bool isEmpty() const;
     void resize(qsizetype size);
diff --git a/src/tools/qdbuscpp2xml/qdbuscpp2xml.cpp b/src/tools/qdbuscpp2xml/qdbuscpp2xml.cpp
index 554ab0119e1..967f567a6da 100644
--- a/src/tools/qdbuscpp2xml/qdbuscpp2xml.cpp
+++ b/src/tools/qdbuscpp2xml/qdbuscpp2xml.cpp
@@ -367,7 +367,7 @@ static void parseCmdLine(QStringList &arguments)
         if (!arg.startsWith(QLatin1Char('-')))
             continue;
 
-        char c = arg.count() == 2 ? arg.at(1).toLatin1() : char(0);
+        char c = arg.size() == 2 ? arg.at(1).toLatin1() : char(0);
         switch (c) {
         case 'P':
             flags |= QDBusConnection::ExportNonScriptableProperties;
diff --git a/src/tools/qvkgen/qvkgen.cpp b/src/tools/qvkgen/qvkgen.cpp
index 8b59d8880c9..6b0e7520a71 100644
--- a/src/tools/qvkgen/qvkgen.cpp
+++ b/src/tools/qvkgen/qvkgen.cpp
@@ -586,10 +586,10 @@ bool genVulkanFunctionsPC(const QList<VkSpecParser::Command> &commands,
         devCmdWrapperStr += "#endif\n\n";
     }
 
-    if (devCmdNamesStr.count() > 2)
-        devCmdNamesStr = devCmdNamesStr.left(devCmdNamesStr.count() - 2);
-    if (instCmdNamesStr.count() > 2)
-        instCmdNamesStr = instCmdNamesStr.left(instCmdNamesStr.count() - 2);
+    if (devCmdNamesStr.size() > 2)
+        devCmdNamesStr.chop(2);
+    if (instCmdNamesStr.size() > 2)
+        instCmdNamesStr.chop(2);
 
     const QString str =
             QString::asprintf(s, preamble.get(licHeaderFn).constData(),
diff --git a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
index 37b9c90ab40..91611dd0b0f 100644
--- a/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
+++ b/tests/auto/corelib/text/qbytearray/tst_qbytearray.cpp
@@ -2515,7 +2515,12 @@ void tst_QByteArray::length()
 
     QCOMPARE(src.length(), res);
     QCOMPARE(src.size(), res);
+#if QT_DEPRECATED_SINCE(6, 4)
+QT_WARNING_PUSH
+QT_WARNING_DISABLE_DEPRECATED
     QCOMPARE(src.count(), res);
+QT_WARNING_POP
+#endif
 }
 
 void tst_QByteArray::length_data()
diff --git a/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp b/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
index 32a0374fcd3..921c6d46f24 100644
--- a/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
+++ b/tests/auto/gui/text/qtextlayout/tst_qtextlayout.cpp
@@ -1084,7 +1084,7 @@ void tst_QTextLayout::defaultWordSeparators_data()
 
     QString separators(".,:;-<>[](){}=/+%&^*");
     separators += QLatin1String("!?");
-    for (int i = 0; i < separators.count(); ++i) {
+    for (int i = 0; i < separators.size(); ++i) {
         QTest::newRow(QString::number(i).toLatin1().data())
             << QString::fromLatin1("abcd") + separators.at(i) + QString::fromLatin1("efgh")
             <<  0 << 4;
diff --git a/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp b/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
index 23c4ed87729..a39e04e58e5 100644
--- a/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
+++ b/tests/auto/network/access/qnetworkreply/tst_qnetworkreply.cpp
@@ -2724,8 +2724,8 @@ void tst_QNetworkReply::postToHttpMultipart()
 
     QCOMPARE(reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt(), 200); // 200 Ok
 
-    QVERIFY(multiPart->boundary().count() > 20); // check that there is randomness after the "boundary_.oOo._" string
-    QVERIFY(multiPart->boundary().count() < 70);
+    QVERIFY(multiPart->boundary().size() > 20); // check that there is randomness after the "boundary_.oOo._" string
+    QVERIFY(multiPart->boundary().size() < 70);
     QByteArray replyData = reply->readAll();
 
     expectedReplyData.prepend("content type: multipart/" + contentType + "; boundary=\"" + multiPart->boundary() + "\"\n");
@@ -2812,8 +2812,8 @@ void tst_QNetworkReply::putToHttpMultipart()
 
     QCOMPARE(reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt(), 200); // 200 Ok
 
-    QVERIFY(multiPart->boundary().count() > 20); // check that there is randomness after the "boundary_.oOo._" string
-    QVERIFY(multiPart->boundary().count() < 70);
+    QVERIFY(multiPart->boundary().size() > 20); // check that there is randomness after the "boundary_.oOo._" string
+    QVERIFY(multiPart->boundary().size() < 70);
     QByteArray replyData = reply->readAll();
 
     expectedReplyData.prepend("content type: multipart/" + contentType + "; boundary=\"" + multiPart->boundary() + "\"\n");
@@ -3030,8 +3030,8 @@ void tst_QNetworkReply::postToHttpsMultipart()
 
     QCOMPARE(reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt(), 200); // 200 Ok
 
-    QVERIFY(multiPart->boundary().count() > 20); // check that there is randomness after the "boundary_.oOo._" string
-    QVERIFY(multiPart->boundary().count() < 70);
+    QVERIFY(multiPart->boundary().size() > 20); // check that there is randomness after the "boundary_.oOo._" string
+    QVERIFY(multiPart->boundary().size() < 70);
     QByteArray replyData = reply->readAll();
 
     expectedReplyData.prepend("content type: multipart/" + contentType + "; boundary=\"" + multiPart->boundary() + "\"\n");
@@ -9013,8 +9013,8 @@ void tst_QNetworkReply::ioHttpRedirectMultipartPost()
 
     QCOMPARE(reply->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt(), 200); // 200 OK
 
-    QVERIFY(multiPart->boundary().count() > 20); // check that there is randomness after the "boundary_.oOo._" string
-    QVERIFY(multiPart->boundary().count() < 70);
+    QVERIFY(multiPart->boundary().size() > 20); // check that there is randomness after the "boundary_.oOo._" string
+    QVERIFY(multiPart->boundary().size() < 70);
     QByteArray replyData = reply->readAll();
 
     expectedReplyData.prepend("content type: multipart/" + contentType + "; boundary=\"" + multiPart->boundary() + "\"\n");
@@ -9179,7 +9179,7 @@ public slots:
         }
         if (m_receivedData.length() > 0 && !m_expectedData.startsWith(m_receivedData)) {
             // We had received some data but it is corrupt!
-            qDebug() << "CORRUPT" << m_receivedData.count();
+            qDebug() << "CORRUPT" << m_receivedData.size();
 
 #if 0 // Use this to track down the pattern of the corruption and conclude the source
             QFile a("/tmp/corrupt");
diff --git a/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp b/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp
index 5b7b8f312b7..d10396b941a 100644
--- a/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp
+++ b/tests/auto/sql/kernel/qsqlquery/tst_qsqlquery.cpp
@@ -844,9 +844,9 @@ void tst_QSqlQuery::oraClob()
 
     QVERIFY_SQL(q, exec(QLatin1String("select bl, cl from %1 where id = 3").arg(clobby)));
     QVERIFY(q.next());
-    QCOMPARE(q.value(0).toString().count(), loong.count());
+    QCOMPARE(q.value(0).toString().size(), loong.size());
     QVERIFY(q.value(0).toString() == loong); // Deliberately not QCOMPARE() as too long
-    QCOMPARE(q.value(1).toByteArray().count(), loong.toLatin1().count());
+    QCOMPARE(q.value(1).toByteArray().size(), loong.toLatin1().size());
     QVERIFY(q.value(1).toByteArray() == loong.toLatin1()); // ditto
 }
 
@@ -868,7 +868,7 @@ void tst_QSqlQuery::oraClobBatch()
 
     QVERIFY_SQL(q, exec("select cl from " + clobBatch));
     QVERIFY(q.next());
-    QCOMPARE(q.value(0).toString().count(), longString.size());
+    QCOMPARE(q.value(0).toString().size(), longString.size());
     QVERIFY(q.value(0).toString() == longString); // As above. deliberately not QCOMPARE().
 }
 
diff --git a/tests/auto/tools/moc/tst_moc.cpp b/tests/auto/tools/moc/tst_moc.cpp
index 7f4b431c81f..5a129e78eb2 100644
--- a/tests/auto/tools/moc/tst_moc.cpp
+++ b/tests/auto/tools/moc/tst_moc.cpp
@@ -1288,9 +1288,9 @@ void tst_Moc::winNewline()
     QVERIFY(f.open(QIODevice::ReadOnly)); // no QIODevice::Text!
     QByteArray data = f.readAll();
     f.close();
-    for (int i = 0; i < data.count(); ++i) {
+    for (int i = 0; i < data.size(); ++i) {
         if (data.at(i) == QLatin1Char('\r')) {
-            QVERIFY(i < data.count() - 1);
+            QVERIFY(i < data.size() - 1);
             ++i;
             QCOMPARE(data.at(i), '\n');
         } else {
diff --git a/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp b/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
index 877c61fb645..e1833a37163 100644
--- a/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
+++ b/tests/auto/widgets/dialogs/qfiledialog/tst_qfiledialog.cpp
@@ -530,7 +530,7 @@ void tst_QFiledialog::completer()
     }
 
     // press 'keys' for the input
-    for (int i = 0; i < input.count(); ++i)
+    for (int i = 0; i < input.size(); ++i)
         QTest::keyPress(lineEdit, input[i].toLatin1());
 
     QStringList expectedFiles;
diff --git a/tests/auto/widgets/dialogs/qfiledialog2/tst_qfiledialog2.cpp b/tests/auto/widgets/dialogs/qfiledialog2/tst_qfiledialog2.cpp
index 8261bd85d61..3c6c80a1e3b 100644
--- a/tests/auto/widgets/dialogs/qfiledialog2/tst_qfiledialog2.cpp
+++ b/tests/auto/widgets/dialogs/qfiledialog2/tst_qfiledialog2.cpp
@@ -825,7 +825,7 @@ void tst_QFileDialog2::task203703_returnProperSeparator()
     QVERIFY(button);
     QTest::keyClick(button, Qt::Key_Return);
     QString result = fd.selectedFiles().first();
-    QVERIFY(result.at(result.count() - 1) != '/');
+    QVERIFY(result.at(result.size() - 1) != '/');
     QVERIFY(!result.contains('\\'));
     current.rmdir("aaaaaaaaaaaaaaaaaa");
 }
diff --git a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
index b9675b1c0d8..ea0d5e8871f 100644
--- a/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
+++ b/tests/auto/widgets/kernel/qwidget/tst_qwidget.cpp
@@ -4019,7 +4019,7 @@ void tst_QWidget::restoreVersion1Geometry()
     QVERIFY(f.exists());
     f.open(QIODevice::ReadOnly);
     const QByteArray savedGeometry = f.readAll();
-    QCOMPARE(savedGeometry.count(), 46);
+    QCOMPARE(savedGeometry.size(), 46);
     f.close();
 
     QWidget widget;