diff --git a/tests/auto/gui/text/CMakeLists.txt b/tests/auto/gui/text/CMakeLists.txt
index 30b35fb10a3..3283ae00970 100644
--- a/tests/auto/gui/text/CMakeLists.txt
+++ b/tests/auto/gui/text/CMakeLists.txt
@@ -4,6 +4,7 @@
 add_subdirectory(qabstracttextdocumentlayout)
 add_subdirectory(qfont)
 add_subdirectory(qfontdatabase)
+add_subdirectory(qfontengine)
 add_subdirectory(qfontmetrics)
 add_subdirectory(qglyphrun)
 add_subdirectory(qrawfont)
diff --git a/tests/auto/gui/text/qfontengine/CMakeLists.txt b/tests/auto/gui/text/qfontengine/CMakeLists.txt
new file mode 100644
index 00000000000..a68bc1148b8
--- /dev/null
+++ b/tests/auto/gui/text/qfontengine/CMakeLists.txt
@@ -0,0 +1,40 @@
+# Copyright (C) 2024 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+#####################################################################
+## tst_qfontengine Test:
+#####################################################################
+
+if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_BUILDING_QT)
+    cmake_minimum_required(VERSION 3.16)
+    project(tst_qfontengine LANGUAGES CXX)
+    find_package(Qt6BuildInternals REQUIRED COMPONENTS STANDALONE_TEST)
+endif()
+
+# Resources:
+set_source_files_properties("../../../shared/resources/test.ttf"
+    PROPERTIES QT_RESOURCE_ALIAS "test.ttf"
+)
+set_source_files_properties("../../../shared/resources/testfont.ttf"
+    PROPERTIES QT_RESOURCE_ALIAS "testfont.ttf"
+)
+set_source_files_properties("../../../shared/resources/testfont_variable.ttf"
+    PROPERTIES QT_RESOURCE_ALIAS "testfont_variable.ttf"
+)
+set(testfonts_resource_files
+    "../../../shared/resources/test.ttf"
+    "../../../shared/resources/testfont.ttf"
+    "../../../shared/resources/testfont_variable.ttf"
+)
+
+qt_internal_add_test(tst_qfontengine
+    SOURCES
+        tst_qfontengine.cpp
+    TESTDATA
+        ${testfonts_resource_files}
+    LIBRARIES
+        Qt::CorePrivate
+        Qt::Gui
+        Qt::GuiPrivate
+    BUILTIN_TESTDATA
+)
diff --git a/tests/auto/gui/text/qfontengine/tst_qfontengine.cpp b/tests/auto/gui/text/qfontengine/tst_qfontengine.cpp
new file mode 100644
index 00000000000..33b285f01dc
--- /dev/null
+++ b/tests/auto/gui/text/qfontengine/tst_qfontengine.cpp
@@ -0,0 +1,257 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#include <QTest>
+
+#include <QtGui/qfont.h>
+#include <QtGui/qfontdatabase.h>
+#include <QtGui/qfontinfo.h>
+#include <QtGui/private/qfont_p.h>
+#include <QtGui/private/qfontengine_p.h>
+
+using namespace Qt::StringLiterals;
+
+class tst_QFontEngine : public QObject
+{
+    Q_OBJECT
+
+    struct Candidate {
+        QLatin1StringView rowName;
+        int expectedGlyphCount;
+        int ucs4;
+        glyph_t expectedGlyphIndex;
+
+        QString familyName() const
+        {
+            const auto split = rowName.indexOf('@');
+            Q_ASSERT(split >= 0);
+            return QString::fromUtf8(rowName.mid(split + 1));
+        }
+
+        QFont font() const
+        {
+            QFont font(familyName());
+            font.setStyleStrategy(QFont::NoFontMerging);
+            return font;
+        }
+
+        bool isFontAvailable() const
+        {
+            QFont theFont(font());
+            return theFont.family() == QFontInfo(theFont).family();
+        }
+
+        QFontEngine *fontEngine() const
+        {
+            return QFontPrivate::get(font())->engineForScript(QChar::Script_Common);
+        }
+    };
+
+public:
+    tst_QFontEngine() = default;
+
+private slots:
+    void initTestCase_data();
+    void init();
+    void cleanup();
+
+    void glyphCount_data() { data(); }
+    void glyphCount();
+    void glyphIndex_data() { data(); }
+    void glyphIndex();
+
+private:
+    void setupApplication();
+    void data();
+
+    // member variables to keep the arguments data alive
+    QByteArray platformArgument;
+    QList<const char *> theArguments;
+    std::unique_ptr<QGuiApplication> theApp;
+
+    int QtsSpecialTestFont = -1;
+    int QtBidiTestFont = -1;
+    int QtTestVariableFont = -1;
+};
+
+// The tst_bench_QFontEngine benchmark project shares the test class declaration
+// and the common setup code here. The file is both compiled as part of the
+// project (moc needs to see it), and included (so that the benchmark code sees
+// the class declaration).
+#if !defined(QFONTENGINE_BENCHMARK) || defined(QFONTENGINE_COMMON)
+
+void tst_QFontEngine::initTestCase_data()
+{
+    QTest::addColumn<QByteArray>("platform");
+    QTest::addColumn<QByteArray>("engine");
+    QTest::addColumn<QFontEngine::Type>("engineType");
+
+#if defined(Q_OS_WIN)
+    QTest::addRow("DirectWrite") << ""_ba << ""_ba << QFontEngine::DirectWrite;
+    QTest::addRow("GDI") << "windows"_ba << "gdi"_ba << QFontEngine::Win;
+    QTest::addRow("Freetype") << "windows"_ba << "freetype"_ba << QFontEngine::Freetype;
+#elif defined(Q_OS_DARWIN)
+    QTest::addRow("CoreText") << ""_ba << ""_ba << QFontEngine::Mac;
+    QTest::addRow("Freetype") << "cocoa"_ba << "freetype"_ba << QFontEngine::Freetype;
+#else
+    QTest::addRow("freetype") << ""_ba << ""_ba << QFontEngine::Freetype;
+#endif
+}
+
+void tst_QFontEngine::init()
+{
+    setupApplication();
+
+#if !defined(QFONTENGINE_BENCHMARK)
+    QtsSpecialTestFont = QFontDatabase::addApplicationFont(QFINDTESTDATA("test.ttf"));
+    QVERIFY(QtsSpecialTestFont >= 0);
+    QCOMPARE(QFontDatabase::applicationFontFamilies(QtsSpecialTestFont),
+             QStringList{u"QtsSpecialTestFont"_s});
+    QtBidiTestFont = QFontDatabase::addApplicationFont(QFINDTESTDATA("testfont.ttf"));
+    QVERIFY(QtBidiTestFont >= 0);
+    QCOMPARE(QFontDatabase::applicationFontFamilies(QtBidiTestFont),
+             QStringList{u"QtBidiTestFont"_s});
+    // This font comes with two font faces, so we get multiple entries (which
+    // might be a bug, esp since on macOS we get two, on Windows we get three
+    // identical families).
+    QtTestVariableFont = QFontDatabase::addApplicationFont(QFINDTESTDATA("testfont_variable.ttf"));
+    QVERIFY(QtTestVariableFont >= 0);
+    QVERIFY(QFontDatabase::applicationFontFamilies(QtTestVariableFont)
+                            .contains(u"QtTestVariableFont"_s));
+#endif
+}
+
+void tst_QFontEngine::cleanup()
+{
+#if !defined(QFONTENGINE_BENCHMARK)
+    QFontDatabase::removeApplicationFont(QtTestVariableFont);
+    QFontDatabase::removeApplicationFont(QtBidiTestFont);
+    QFontDatabase::removeApplicationFont(QtsSpecialTestFont);
+#endif
+
+    theApp.reset();
+    theArguments = {};
+}
+
+void tst_QFontEngine::setupApplication()
+{
+    if (theApp)
+        return;
+    QFETCH_GLOBAL(const QByteArray, platform);
+    QFETCH_GLOBAL(const QByteArray, engine);
+
+    QList<const char *> arguments = {"tst_qfontengine"};
+    if (!platform.isEmpty()) {
+        arguments += "-platform";
+        platformArgument = platform + ":fontengine=" + engine;
+        arguments += platformArgument.data();
+    }
+
+    theArguments = arguments;
+    int argc = arguments.size();
+    theApp = std::make_unique<QGuiApplication>(argc, const_cast<char **>(theArguments.data()));
+}
+
+// only called once per test function, even if the global data (i.e. font engine) changed!
+void tst_QFontEngine::data()
+{
+    QTest::addColumn<Candidate>("candidate");
+
+    const std::initializer_list<Candidate> candidates = {
+#if !defined(QFONTENGINE_BENCHMARK)
+        // our own testfonts
+        {
+            ".notdef@QtsSpecialTestFont"_L1,
+            6, 0x0000, 0,
+        },
+        {
+            "Dotty@QtsSpecialTestFont"_L1,
+            6, 0xe000, 1,
+        },
+        {
+            "A@QtsSpecialTestFont"_L1,
+            6, 0x0041, 2,
+        },
+        {
+            "one@QtsSpecialTestFont"_L1,
+            6, 0x0031, 3,
+        },
+        {
+            "uni200D@QtsSpecialTestFont"_L1,
+            6, 0x200d, 4,
+        },
+        {
+            "uniFFFC@QtsSpecialTestFont"_L1,
+            6, 0xfffc, 5,
+        },
+        {
+            "percent@QtBidiTestFont"_L1,
+            150, 0x0025, 13,
+        },
+        { // up arrow, beyond 0xFFFF
+            "u1034A@QtBidiTestFont"_L1,
+            150, 0x1034A, 149,
+        },
+        {
+            "peseta@QtTestVariableFont"_L1,
+            235, 0x20a7, 218,
+        },
+#else // some typical icon fonts that might be present on the system, but also change frequently
+        {   // early hit
+            "faucet@Font Awesome 6 Free"_L1,
+            1399, 0xe005, 51,
+        },
+        {   // last glyph in the font
+            "caravan@Font Awesome 6 Free"_L1,
+            1399, 0xf8ff, 1398,
+        },
+        {
+            "delete@Material Symbols Outlined"_L1,
+            5032, 0xe872, 1,
+        },
+        {   // the Segoe Fluent Icons font that comes with Windows 11
+            "gid1486@Segoe Fluent Icons"_L1, // voicemail
+            1529, 0xf47f, 1486,
+        },
+#endif // !defined(QFONTENGINE_BENCHMARK)
+    };
+
+    for (auto candidate : candidates)
+        QTest::addRow("%s", candidate.rowName.constData()) << candidate;
+}
+
+#include "tst_qfontengine.moc"
+QTEST_APPLESS_MAIN(tst_QFontEngine)
+
+#endif // !defined(QFONTENGINE_BENCHMARK) || defined(QFONTENGINE_COMMON)
+
+// The benchmark project implements the test functions differently.
+
+#if !defined(QFONTENGINE_BENCHMARK)
+
+void tst_QFontEngine::glyphCount()
+{
+    QFETCH_GLOBAL(const QFontEngine::Type, engineType);
+    QFETCH(const Candidate, candidate);
+    if (!candidate.isFontAvailable())
+        QSKIP("Font is not available");
+
+    const auto fontEngine = candidate.fontEngine();
+    QCOMPARE(fontEngine->type(), engineType);
+    QCOMPARE(fontEngine->glyphCount(), candidate.expectedGlyphCount);
+}
+
+void tst_QFontEngine::glyphIndex()
+{
+    QFETCH_GLOBAL(const QFontEngine::Type, engineType);
+    QFETCH(const Candidate, candidate);
+    if (!candidate.isFontAvailable())
+        QSKIP("Font is not available");
+
+    const auto fontEngine = candidate.fontEngine();
+    QCOMPARE(fontEngine->type(), engineType);
+    QCOMPARE(fontEngine->glyphIndex(candidate.ucs4), candidate.expectedGlyphIndex);
+}
+
+#endif // !define(QFONTENGINE_BENCHMARK)
+
diff --git a/tests/benchmarks/gui/text/CMakeLists.txt b/tests/benchmarks/gui/text/CMakeLists.txt
index 052d49e03c2..05e4b873079 100644
--- a/tests/benchmarks/gui/text/CMakeLists.txt
+++ b/tests/benchmarks/gui/text/CMakeLists.txt
@@ -1,6 +1,7 @@
 # Copyright (C) 2022 The Qt Company Ltd.
 # SPDX-License-Identifier: BSD-3-Clause
 
+add_subdirectory(qfontengine)
 add_subdirectory(qfontmetrics)
 add_subdirectory(qtext)
 add_subdirectory(qtextdocument)
diff --git a/tests/benchmarks/gui/text/qfontengine/CMakeLists.txt b/tests/benchmarks/gui/text/qfontengine/CMakeLists.txt
new file mode 100644
index 00000000000..ddd3797a661
--- /dev/null
+++ b/tests/benchmarks/gui/text/qfontengine/CMakeLists.txt
@@ -0,0 +1,18 @@
+# Copyright (C) 2024 The Qt Company Ltd.
+# SPDX-License-Identifier: BSD-3-Clause
+
+#####################################################################
+## tst_bench_QFontEngine Binary:
+#####################################################################
+
+qt_internal_add_benchmark(tst_bench_QFontEngine
+    SOURCES
+        ../../../../auto/gui/text/qfontengine/tst_qfontengine.cpp
+        tst_qfontengine.cpp
+    DEFINES
+        QFONTENGINE_BENCHMARK
+    LIBRARIES
+        Qt::Gui
+        Qt::GuiPrivate
+        Qt::Test
+)
diff --git a/tests/benchmarks/gui/text/qfontengine/tst_qfontengine.cpp b/tests/benchmarks/gui/text/qfontengine/tst_qfontengine.cpp
new file mode 100644
index 00000000000..15236d4c596
--- /dev/null
+++ b/tests/benchmarks/gui/text/qfontengine/tst_qfontengine.cpp
@@ -0,0 +1,33 @@
+// Copyright (C) 2024 The Qt Company Ltd.
+// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR GPL-3.0-only
+
+#define QFONTENGINE_COMMON
+#include "../../../../auto/gui/text/qfontengine/tst_qfontengine.cpp"
+
+using namespace Qt::StringLiterals;
+
+void tst_QFontEngine::glyphCount()
+{
+    QFETCH(const Candidate, candidate);
+    if (!candidate.isFontAvailable())
+        QSKIP("Font is not available");
+
+    const auto fontEngine = candidate.fontEngine();
+
+    QBENCHMARK {
+        fontEngine->glyphCount();
+    }
+}
+
+void tst_QFontEngine::glyphIndex()
+{
+    QFETCH(const Candidate, candidate);
+    if (!candidate.isFontAvailable())
+        QSKIP("Font is not available");
+
+    const auto fontEngine = candidate.fontEngine();
+
+    QBENCHMARK {
+        fontEngine->glyphIndex(candidate.ucs4);
+    }
+}