diff --git a/CMakeLists.txt b/CMakeLists.txt
index 2069950..b4a39fb 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -37,11 +37,13 @@ target_sources(pineapple-notepad
 PRIVATE
     main.cpp
     mainwindow.cpp mainwindow.h
+    findreplacedialog.cpp findreplacedialog.h
     sciedit.cpp sciedit.h
     tabwidget.cpp tabwidget.h
     documentmanager.cpp documentmanager.h
     editorviewhelper.cpp editorviewhelper.h
     generalsettings.ui
+    findreplacedialog.ui
 
     appsettings.kcfg
 )
diff --git a/findreplacedialog.cpp b/findreplacedialog.cpp
new file mode 100644
index 0000000..177cf76
--- /dev/null
+++ b/findreplacedialog.cpp
@@ -0,0 +1,325 @@
+#include "findreplacedialog.h"
+
+#include "ui_findreplacedialog.h"
+
+#include <QCheckBox>
+#include <QCloseEvent>
+#include <QComboBox>
+#include <QLineEdit>
+#include <QPushButton>
+#include <QTabWidget>
+
+static QString decodeExtended(const QString &s)
+{
+    QString out;
+    out.reserve(s.size());
+
+    for (int i = 0; i < s.size(); ++i) {
+        const QChar c = s.at(i);
+        if (c != QLatin1Char('\\') || i + 1 >= s.size()) {
+            out.append(c);
+            continue;
+        }
+
+        const QChar n = s.at(i + 1);
+        if (n == QLatin1Char('n')) {
+            out.append(QLatin1Char('\n'));
+            ++i;
+        } else if (n == QLatin1Char('r')) {
+            out.append(QLatin1Char('\r'));
+            ++i;
+        } else if (n == QLatin1Char('t')) {
+            out.append(QLatin1Char('\t'));
+            ++i;
+        } else if (n == QLatin1Char('\\')) {
+            out.append(QLatin1Char('\\'));
+            ++i;
+        } else if (n == QLatin1Char('0')) {
+            out.append(QChar(0));
+            ++i;
+        } else if (n == QLatin1Char('x') && i + 3 < s.size()) {
+            bool ok = false;
+            const QString hex = s.mid(i + 2, 2);
+            const int code = hex.toInt(&ok, 16);
+            if (ok) {
+                out.append(QChar(code));
+                i += 3;
+            } else {
+                out.append(c);
+            }
+        } else {
+            out.append(n);
+            ++i;
+        }
+    }
+
+    return out;
+}
+
+FindReplaceDialog::FindReplaceDialog(QWidget *parent)
+    : QDialog(parent)
+    , ui(new Ui::FindReplaceDialog)
+{
+    ui->setupUi(this);
+    setModal(false);
+    setWindowFlags(windowFlags() | Qt::Tool);
+
+    initCombos();
+    initModeCombos();
+    initSync();
+
+    connect(ui->tabWidget, &QTabWidget::currentChanged, this, [this](int index) {
+        Q_UNUSED(index)
+        if (ui->tabWidget->currentWidget() == ui->findTab) {
+            syncFromReplaceTab();
+        } else {
+            syncFromFindTab();
+        }
+    });
+
+    connect(ui->findNextBtnFind, &QPushButton::clicked, this, [this]() {
+        commitHistory();
+        emit findRequested(true);
+    });
+    connect(ui->findPrevBtnFind, &QPushButton::clicked, this, [this]() {
+        commitHistory();
+        emit findRequested(false);
+    });
+    connect(ui->closeBtnFind, &QPushButton::clicked, this, &QDialog::hide);
+
+    connect(ui->findNextBtnReplace, &QPushButton::clicked, this, [this]() {
+        commitHistory();
+        emit findRequested(true);
+    });
+    connect(ui->replaceBtn, &QPushButton::clicked, this, [this]() {
+        commitHistory();
+        emit replaceRequested();
+    });
+    connect(ui->replaceAllBtn, &QPushButton::clicked, this, [this]() {
+        commitHistory();
+        emit replaceAllRequested();
+    });
+    connect(ui->closeBtnReplace, &QPushButton::clicked, this, &QDialog::hide);
+
+    resize(520, sizeHint().height());
+}
+
+FindReplaceDialog::~FindReplaceDialog()
+{
+    delete ui;
+}
+
+void FindReplaceDialog::initCombos()
+{
+    ui->findWhatComboFind->setInsertPolicy(QComboBox::NoInsert);
+    ui->findWhatComboReplace->setInsertPolicy(QComboBox::NoInsert);
+    ui->replaceWithComboReplace->setInsertPolicy(QComboBox::NoInsert);
+}
+
+void FindReplaceDialog::initModeCombos()
+{
+    ui->modeComboFind->addItem(QStringLiteral("Normal"), QVariant::fromValue(static_cast<int>(SearchMode::Normal)));
+    ui->modeComboFind->addItem(QStringLiteral("Extended (\\n, \\r, \\t, \\0, \\xNN)"), QVariant::fromValue(static_cast<int>(SearchMode::Extended)));
+    ui->modeComboFind->addItem(QStringLiteral("Regular expression"), QVariant::fromValue(static_cast<int>(SearchMode::Regex)));
+
+    ui->modeComboReplace->addItem(QStringLiteral("Normal"), QVariant::fromValue(static_cast<int>(SearchMode::Normal)));
+    ui->modeComboReplace->addItem(QStringLiteral("Extended (\\n, \\r, \\t, \\0, \\xNN)"), QVariant::fromValue(static_cast<int>(SearchMode::Extended)));
+    ui->modeComboReplace->addItem(QStringLiteral("Regular expression"), QVariant::fromValue(static_cast<int>(SearchMode::Regex)));
+}
+
+void FindReplaceDialog::initSync()
+{
+    if (ui->findWhatComboFind->lineEdit()) {
+        connect(ui->findWhatComboFind->lineEdit(), &QLineEdit::textEdited, this, [this]() { syncFromFindTab(); });
+    }
+    connect(ui->matchCaseCheckFind, &QCheckBox::toggled, this, [this]() { syncFromFindTab(); });
+    connect(ui->wholeWordCheckFind, &QCheckBox::toggled, this, [this]() { syncFromFindTab(); });
+    connect(ui->wrapAroundCheckFind, &QCheckBox::toggled, this, [this]() { syncFromFindTab(); });
+    connect(ui->inSelectionCheckFind, &QCheckBox::toggled, this, [this]() { syncFromFindTab(); });
+    connect(ui->modeComboFind, &QComboBox::currentIndexChanged, this, [this](int) { syncFromFindTab(); });
+
+    if (ui->findWhatComboReplace->lineEdit()) {
+        connect(ui->findWhatComboReplace->lineEdit(), &QLineEdit::textEdited, this, [this]() { syncFromReplaceTab(); });
+    }
+    if (ui->replaceWithComboReplace->lineEdit()) {
+        connect(ui->replaceWithComboReplace->lineEdit(), &QLineEdit::textEdited, this, [this]() { syncFromReplaceTab(); });
+    }
+    connect(ui->matchCaseCheckReplace, &QCheckBox::toggled, this, [this]() { syncFromReplaceTab(); });
+    connect(ui->wholeWordCheckReplace, &QCheckBox::toggled, this, [this]() { syncFromReplaceTab(); });
+    connect(ui->wrapAroundCheckReplace, &QCheckBox::toggled, this, [this]() { syncFromReplaceTab(); });
+    connect(ui->inSelectionCheckReplace, &QCheckBox::toggled, this, [this]() { syncFromReplaceTab(); });
+    connect(ui->modeComboReplace, &QComboBox::currentIndexChanged, this, [this](int) { syncFromReplaceTab(); });
+
+    syncFromFindTab();
+}
+
+void FindReplaceDialog::syncFromFindTab()
+{
+    if (m_syncing) {
+        return;
+    }
+    m_syncing = true;
+    ui->findWhatComboReplace->setCurrentText(ui->findWhatComboFind->currentText());
+    ui->matchCaseCheckReplace->setChecked(ui->matchCaseCheckFind->isChecked());
+    ui->wholeWordCheckReplace->setChecked(ui->wholeWordCheckFind->isChecked());
+    ui->wrapAroundCheckReplace->setChecked(ui->wrapAroundCheckFind->isChecked());
+    ui->inSelectionCheckReplace->setChecked(ui->inSelectionCheckFind->isChecked());
+    ui->modeComboReplace->setCurrentIndex(ui->modeComboFind->currentIndex());
+    m_syncing = false;
+}
+
+void FindReplaceDialog::syncFromReplaceTab()
+{
+    if (m_syncing) {
+        return;
+    }
+    m_syncing = true;
+    ui->findWhatComboFind->setCurrentText(ui->findWhatComboReplace->currentText());
+    ui->matchCaseCheckFind->setChecked(ui->matchCaseCheckReplace->isChecked());
+    ui->wholeWordCheckFind->setChecked(ui->wholeWordCheckReplace->isChecked());
+    ui->wrapAroundCheckFind->setChecked(ui->wrapAroundCheckReplace->isChecked());
+    ui->inSelectionCheckFind->setChecked(ui->inSelectionCheckReplace->isChecked());
+    ui->modeComboFind->setCurrentIndex(ui->modeComboReplace->currentIndex());
+    m_syncing = false;
+}
+
+void FindReplaceDialog::openFind()
+{
+    ui->tabWidget->setCurrentWidget(ui->findTab);
+    show();
+    raise();
+    activateWindow();
+    ui->findWhatComboFind->setFocus();
+    if (ui->findWhatComboFind->lineEdit()) {
+        ui->findWhatComboFind->lineEdit()->selectAll();
+    }
+}
+
+void FindReplaceDialog::openReplace()
+{
+    ui->tabWidget->setCurrentWidget(ui->replaceTab);
+    show();
+    raise();
+    activateWindow();
+    ui->findWhatComboReplace->setFocus();
+    if (ui->findWhatComboReplace->lineEdit()) {
+        ui->findWhatComboReplace->lineEdit()->selectAll();
+    }
+}
+
+QString FindReplaceDialog::findText() const
+{
+    if (ui->tabWidget->currentWidget() == ui->replaceTab) {
+        return ui->findWhatComboReplace->currentText();
+    }
+    return ui->findWhatComboFind->currentText();
+}
+
+QString FindReplaceDialog::replaceText() const
+{
+    return ui->replaceWithComboReplace->currentText();
+}
+
+QString FindReplaceDialog::findTextForSearch() const
+{
+    const QString raw = findText();
+    if (searchMode() == SearchMode::Extended) {
+        return decodeExtended(raw);
+    }
+    return raw;
+}
+
+QString FindReplaceDialog::replaceTextForReplace() const
+{
+    const QString raw = replaceText();
+    if (searchMode() == SearchMode::Extended) {
+        return decodeExtended(raw);
+    }
+    return raw;
+}
+
+bool FindReplaceDialog::matchCase() const
+{
+    if (ui->tabWidget->currentWidget() == ui->replaceTab) {
+        return ui->matchCaseCheckReplace->isChecked();
+    }
+    return ui->matchCaseCheckFind->isChecked();
+}
+
+bool FindReplaceDialog::wholeWord() const
+{
+    if (ui->tabWidget->currentWidget() == ui->replaceTab) {
+        return ui->wholeWordCheckReplace->isChecked();
+    }
+    return ui->wholeWordCheckFind->isChecked();
+}
+
+bool FindReplaceDialog::wrapAround() const
+{
+    if (ui->tabWidget->currentWidget() == ui->replaceTab) {
+        return ui->wrapAroundCheckReplace->isChecked();
+    }
+    return ui->wrapAroundCheckFind->isChecked();
+}
+
+bool FindReplaceDialog::inSelection() const
+{
+    if (ui->tabWidget->currentWidget() == ui->replaceTab) {
+        return ui->inSelectionCheckReplace->isChecked();
+    }
+    return ui->inSelectionCheckFind->isChecked();
+}
+
+SearchMode FindReplaceDialog::searchMode() const
+{
+    const int v = (ui->tabWidget->currentWidget() == ui->replaceTab) ? ui->modeComboReplace->currentData().toInt()
+                                                                     : ui->modeComboFind->currentData().toInt();
+    return static_cast<SearchMode>(v);
+}
+
+void FindReplaceDialog::setFindTextIfNotEmpty(const QString &text)
+{
+    if (text.isEmpty()) {
+        return;
+    }
+    ui->findWhatComboFind->setCurrentText(text);
+    ui->findWhatComboReplace->setCurrentText(text);
+    if (ui->tabWidget->currentWidget() == ui->replaceTab) {
+        if (ui->findWhatComboReplace->lineEdit()) {
+            ui->findWhatComboReplace->lineEdit()->selectAll();
+        }
+    } else {
+        if (ui->findWhatComboFind->lineEdit()) {
+            ui->findWhatComboFind->lineEdit()->selectAll();
+        }
+    }
+}
+
+void FindReplaceDialog::commitHistory()
+{
+    const auto commit = [](QComboBox *combo) {
+        const QString v = combo->currentText();
+        if (v.isEmpty()) {
+            return;
+        }
+        const int idx = combo->findText(v);
+        if (idx >= 0) {
+            combo->removeItem(idx);
+        }
+        combo->insertItem(0, v);
+        combo->setCurrentIndex(0);
+        while (combo->count() > 20) {
+            combo->removeItem(combo->count() - 1);
+        }
+    };
+
+    commit(ui->findWhatComboFind);
+    commit(ui->findWhatComboReplace);
+    commit(ui->replaceWithComboReplace);
+}
+
+void FindReplaceDialog::closeEvent(QCloseEvent *event)
+{
+    hide();
+    event->ignore();
+}
diff --git a/findreplacedialog.h b/findreplacedialog.h
new file mode 100644
index 0000000..30066dd
--- /dev/null
+++ b/findreplacedialog.h
@@ -0,0 +1,57 @@
+#pragma once
+
+#include <QDialog>
+
+namespace Ui {
+class FindReplaceDialog;
+}
+
+enum class SearchMode {
+    Normal,
+    Extended,
+    Regex,
+};
+
+class FindReplaceDialog final : public QDialog
+{
+    Q_OBJECT
+
+public:
+    explicit FindReplaceDialog(QWidget *parent = nullptr);
+    ~FindReplaceDialog() override;
+
+    void openFind();
+    void openReplace();
+
+    QString findText() const;
+    QString replaceText() const;
+    QString findTextForSearch() const;
+    QString replaceTextForReplace() const;
+
+    bool matchCase() const;
+    bool wholeWord() const;
+    bool wrapAround() const;
+    bool inSelection() const;
+    SearchMode searchMode() const;
+
+    void setFindTextIfNotEmpty(const QString &text);
+    void commitHistory();
+
+signals:
+    void findRequested(bool forward);
+    void replaceRequested();
+    void replaceAllRequested();
+
+protected:
+    void closeEvent(QCloseEvent *event) override;
+
+private:
+    void initCombos();
+    void initModeCombos();
+    void initSync();
+    void syncFromFindTab();
+    void syncFromReplaceTab();
+
+    Ui::FindReplaceDialog *ui = nullptr;
+    bool m_syncing = false;
+};
diff --git a/findreplacedialog.ui b/findreplacedialog.ui
new file mode 100644
index 0000000..22598b5
--- /dev/null
+++ b/findreplacedialog.ui
@@ -0,0 +1,317 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ui version="4.0">
+ <class>FindReplaceDialog</class>
+ <widget class="QDialog" name="FindReplaceDialog">
+  <property name="windowTitle">
+   <string>Find / Replace</string>
+  </property>
+  <layout class="QVBoxLayout" name="verticalLayout">
+   <item>
+    <widget class="QTabWidget" name="tabWidget">
+     <property name="currentIndex">
+      <number>0</number>
+     </property>
+     <widget class="QWidget" name="findTab">
+      <attribute name="title">
+       <string>Find</string>
+      </attribute>
+      <layout class="QHBoxLayout" name="findTabLayout">
+       <item>
+        <layout class="QVBoxLayout" name="findLeftLayout">
+         <item>
+          <layout class="QFormLayout" name="findFormLayout">
+           <item row="0" column="0">
+            <widget class="QLabel" name="findWhatLabelFind">
+             <property name="text">
+              <string>Find what:</string>
+             </property>
+            </widget>
+           </item>
+           <item row="0" column="1">
+            <widget class="QComboBox" name="findWhatComboFind">
+             <property name="editable">
+              <bool>true</bool>
+             </property>
+            </widget>
+           </item>
+          </layout>
+         </item>
+         <item>
+          <widget class="QGroupBox" name="optionsGroupFind">
+           <property name="title">
+            <string>Search options</string>
+           </property>
+           <layout class="QVBoxLayout" name="optionsLayoutFind">
+            <item>
+             <widget class="QCheckBox" name="matchCaseCheckFind">
+              <property name="text">
+               <string>Match case</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QCheckBox" name="wholeWordCheckFind">
+              <property name="text">
+               <string>Match whole word only</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QCheckBox" name="wrapAroundCheckFind">
+              <property name="text">
+               <string>Wrap around</string>
+              </property>
+              <property name="checked">
+               <bool>true</bool>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QCheckBox" name="inSelectionCheckFind">
+              <property name="text">
+               <string>In selection</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QLabel" name="modeLabelFind">
+              <property name="text">
+               <string>Search mode:</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QComboBox" name="modeComboFind"/>
+            </item>
+           </layout>
+          </widget>
+         </item>
+         <item>
+          <spacer name="verticalSpacerFind">
+           <property name="orientation">
+            <enum>Qt::Vertical</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>20</width>
+             <height>40</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
+       </item>
+       <item>
+        <widget class="QWidget" name="findButtonsWidget">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <layout class="QVBoxLayout" name="findButtonsLayout">
+          <item>
+           <widget class="QPushButton" name="findNextBtnFind">
+            <property name="text">
+             <string>Find Next</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QPushButton" name="findPrevBtnFind">
+            <property name="text">
+             <string>Find Previous</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <spacer name="verticalSpacerFindButtons">
+            <property name="orientation">
+             <enum>Qt::Vertical</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>20</width>
+              <height>40</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+          <item>
+           <widget class="QPushButton" name="closeBtnFind">
+            <property name="text">
+             <string>Close</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+     <widget class="QWidget" name="replaceTab">
+      <attribute name="title">
+       <string>Replace</string>
+      </attribute>
+      <layout class="QHBoxLayout" name="replaceTabLayout">
+       <item>
+        <layout class="QVBoxLayout" name="replaceLeftLayout">
+         <item>
+          <layout class="QFormLayout" name="replaceFormLayout">
+           <item row="0" column="0">
+            <widget class="QLabel" name="findWhatLabelReplace">
+             <property name="text">
+              <string>Find what:</string>
+             </property>
+            </widget>
+           </item>
+           <item row="0" column="1">
+            <widget class="QComboBox" name="findWhatComboReplace">
+             <property name="editable">
+              <bool>true</bool>
+             </property>
+            </widget>
+           </item>
+           <item row="1" column="0">
+            <widget class="QLabel" name="replaceWithLabelReplace">
+             <property name="text">
+              <string>Replace with:</string>
+             </property>
+            </widget>
+           </item>
+           <item row="1" column="1">
+            <widget class="QComboBox" name="replaceWithComboReplace">
+             <property name="editable">
+              <bool>true</bool>
+             </property>
+            </widget>
+           </item>
+          </layout>
+         </item>
+         <item>
+          <widget class="QGroupBox" name="optionsGroupReplace">
+           <property name="title">
+            <string>Search options</string>
+           </property>
+           <layout class="QVBoxLayout" name="optionsLayoutReplace">
+            <item>
+             <widget class="QCheckBox" name="matchCaseCheckReplace">
+              <property name="text">
+               <string>Match case</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QCheckBox" name="wholeWordCheckReplace">
+              <property name="text">
+               <string>Match whole word only</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QCheckBox" name="wrapAroundCheckReplace">
+              <property name="text">
+               <string>Wrap around</string>
+              </property>
+              <property name="checked">
+               <bool>true</bool>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QCheckBox" name="inSelectionCheckReplace">
+              <property name="text">
+               <string>In selection</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QLabel" name="modeLabelReplace">
+              <property name="text">
+               <string>Search mode:</string>
+              </property>
+             </widget>
+            </item>
+            <item>
+             <widget class="QComboBox" name="modeComboReplace"/>
+            </item>
+           </layout>
+          </widget>
+         </item>
+         <item>
+          <spacer name="verticalSpacerReplace">
+           <property name="orientation">
+            <enum>Qt::Vertical</enum>
+           </property>
+           <property name="sizeHint" stdset="0">
+            <size>
+             <width>20</width>
+             <height>40</height>
+            </size>
+           </property>
+          </spacer>
+         </item>
+        </layout>
+       </item>
+       <item>
+        <widget class="QWidget" name="replaceButtonsWidget">
+         <property name="sizePolicy">
+          <sizepolicy hsizetype="Fixed" vsizetype="Preferred">
+           <horstretch>0</horstretch>
+           <verstretch>0</verstretch>
+          </sizepolicy>
+         </property>
+         <layout class="QVBoxLayout" name="replaceButtonsLayout">
+          <item>
+           <widget class="QPushButton" name="findNextBtnReplace">
+            <property name="text">
+             <string>Find Next</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QPushButton" name="replaceBtn">
+            <property name="text">
+             <string>Replace</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <widget class="QPushButton" name="replaceAllBtn">
+            <property name="text">
+             <string>Replace All</string>
+            </property>
+           </widget>
+          </item>
+          <item>
+           <spacer name="verticalSpacerReplaceButtons">
+            <property name="orientation">
+             <enum>Qt::Vertical</enum>
+            </property>
+            <property name="sizeHint" stdset="0">
+             <size>
+              <width>20</width>
+              <height>40</height>
+             </size>
+            </property>
+           </spacer>
+          </item>
+          <item>
+           <widget class="QPushButton" name="closeBtnReplace">
+            <property name="text">
+             <string>Close</string>
+            </property>
+           </widget>
+          </item>
+         </layout>
+        </widget>
+       </item>
+      </layout>
+     </widget>
+    </widget>
+   </item>
+  </layout>
+ </widget>
+ <resources/>
+ <connections/>
+</ui>
diff --git a/mainwindow.cpp b/mainwindow.cpp
index a3cca80..efd21d6 100644
--- a/mainwindow.cpp
+++ b/mainwindow.cpp
@@ -5,12 +5,25 @@
 #include "documentmanager.h"
 #include "appsettings.h"
 #include "editorviewhelper.h"
+#include "findreplacedialog.h"
 
 #include <QActionGroup>
 #include <QApplication>
+#include <QCheckBox>
+#include <QCloseEvent>
+#include <QComboBox>
+#include <QDialog>
+#include <QFormLayout>
+#include <QGroupBox>
+#include <QHBoxLayout>
+#include <QLabel>
+#include <QLineEdit>
 #include <QMenu>
+#include <QPushButton>
 #include <QStringBuilder>
 #include <QStatusBar>
+#include <QTabWidget>
+#include <QVBoxLayout>
 #include <QFileDialog>
 #include <QMessageBox>
 
@@ -98,11 +111,18 @@ void MainWindow::setupActions()
     }, actionCollection());
 
     // "Search" menu
-    KStandardAction::find(this, [](){}, actionCollection());
-    KStandardAction::findNext(this, [](){}, actionCollection());
-    KStandardAction::findPrev(this, [](){}, actionCollection());
-    KStandardAction::replace(this, [](){}, actionCollection());
-    qDebug() << KStandardAction::name(KStandardAction::Replace);
+    KStandardAction::find(this, [this](){
+        showFindReplaceDialog(false);
+    }, actionCollection());
+    KStandardAction::findNext(this, [this](){
+        findNextInCurrentEditor(true, true);
+    }, actionCollection());
+    KStandardAction::findPrev(this, [this](){
+        findNextInCurrentEditor(false, true);
+    }, actionCollection());
+    KStandardAction::replace(this, [this](){
+        showFindReplaceDialog(true);
+    }, actionCollection());
     
     // "Language" menu
     QAction *lexerNoneAction = new QAction(this);
@@ -378,3 +398,326 @@ void MainWindow::updateActions()
         indentGuideAction->setChecked(m_indentGuidesEnabled);
     }
 }
+
+void MainWindow::showFindReplaceDialog(bool showReplace)
+{
+    if (!m_findReplaceDialog) {
+        m_findReplaceDialog = new FindReplaceDialog(this);
+        connect(m_findReplaceDialog, &FindReplaceDialog::findRequested, this, [this](bool forward) {
+            findNextInCurrentEditor(forward, true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceRequested, this, [this]() {
+            replaceOneInCurrentEditor(true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceAllRequested, this, [this]() {
+            replaceAllInCurrentEditor(true);
+        });
+    }
+
+    if (SciEdit *editor = m_tabWidget->currentEditor()) {
+        const int selStart = static_cast<int>(editor->selectionStart());
+        const int selEnd = static_cast<int>(editor->selectionEnd());
+        if (selStart != selEnd) {
+            const int start = qMin(selStart, selEnd);
+            const int end = qMax(selStart, selEnd);
+            const QByteArray selected = editor->textRange(start, end);
+            m_findReplaceDialog->setFindTextIfNotEmpty(QString::fromUtf8(selected));
+        }
+    }
+
+    if (showReplace) {
+        m_findReplaceDialog->openReplace();
+    } else {
+        m_findReplaceDialog->openFind();
+    }
+}
+
+static sptr_t buildSearchFlags(const FindReplaceDialog *dialog)
+{
+    sptr_t flags = 0;
+    if (dialog->matchCase()) {
+        flags |= SCFIND_MATCHCASE;
+    }
+    if (dialog->wholeWord()) {
+        flags |= SCFIND_WHOLEWORD;
+    }
+    if (dialog->searchMode() == SearchMode::Regex) {
+        flags |= SCFIND_REGEXP;
+    }
+    return flags;
+}
+
+static QString buildFindPattern(const FindReplaceDialog *dialog)
+{
+    return dialog->findTextForSearch();
+}
+
+static QString buildReplacementText(const FindReplaceDialog *dialog)
+{
+    return dialog->replaceTextForReplace();
+}
+
+bool MainWindow::findNextInCurrentEditor(bool forward, bool showNotFoundMessage)
+{
+    SciEdit *editor = m_tabWidget->currentEditor();
+    if (!editor) {
+        return false;
+    }
+
+    if (!m_findReplaceDialog) {
+        m_findReplaceDialog = new FindReplaceDialog(this);
+        connect(m_findReplaceDialog, &FindReplaceDialog::findRequested, this, [this](bool forward) {
+            findNextInCurrentEditor(forward, true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceRequested, this, [this]() {
+            replaceOneInCurrentEditor(true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceAllRequested, this, [this]() {
+            replaceAllInCurrentEditor(true);
+        });
+    }
+
+    const QString needle = buildFindPattern(m_findReplaceDialog);
+    if (needle.isEmpty()) {
+        return false;
+    }
+
+    const QByteArray needleBytes = needle.toUtf8();
+    const sptr_t flags = buildSearchFlags(m_findReplaceDialog);
+
+    const int docLen = static_cast<int>(editor->textLength());
+    int rangeStart = 0;
+    int rangeEnd = docLen;
+
+    if (m_findReplaceDialog->inSelection()) {
+        if (!m_findInSelectionEnabled) {
+            const int selStart = static_cast<int>(editor->selectionStart());
+            const int selEnd = static_cast<int>(editor->selectionEnd());
+            if (selStart != selEnd) {
+                m_findSelectionStart = qMin(selStart, selEnd);
+                m_findSelectionEnd = qMax(selStart, selEnd);
+                m_findInSelectionEnabled = true;
+            }
+        }
+    } else {
+        m_findInSelectionEnabled = false;
+    }
+
+    if (m_findInSelectionEnabled) {
+        rangeStart = qBound(0, m_findSelectionStart, docLen);
+        rangeEnd = qBound(0, m_findSelectionEnd, docLen);
+        if (rangeStart >= rangeEnd) {
+            m_findInSelectionEnabled = false;
+            rangeStart = 0;
+            rangeEnd = docLen;
+        }
+    }
+
+    const int selStartNow = static_cast<int>(editor->selectionStart());
+    const int selEndNow = static_cast<int>(editor->selectionEnd());
+    int caretBase = static_cast<int>(editor->currentPos());
+    if (forward && selStartNow != selEndNow) {
+        caretBase = qMax(selStartNow, selEndNow);
+    }
+    caretBase = qBound(rangeStart, caretBase, rangeEnd);
+
+    auto selectMatch = [&](int start, int end) {
+        editor->setSel(start, end);
+        editor->scrollCaret();
+    };
+
+    auto showNotFound = [&]() {
+        if (!showNotFoundMessage) {
+            return;
+        }
+        QMessageBox::information(this, QStringLiteral("Find"), QStringLiteral("Text not found."));
+    };
+
+    if (forward) {
+        const QPair<int, int> found = editor->findText(static_cast<int>(flags), needleBytes.constData(), caretBase, rangeEnd);
+        if (found.first >= 0) {
+            selectMatch(found.first, found.second);
+            return true;
+        }
+        if (m_findReplaceDialog->wrapAround()) {
+            const QPair<int, int> wrapped = editor->findText(static_cast<int>(flags), needleBytes.constData(), rangeStart, rangeEnd);
+            if (wrapped.first >= 0) {
+                selectMatch(wrapped.first, wrapped.second);
+                return true;
+            }
+        }
+        showNotFound();
+        return false;
+    }
+
+    auto findLastBefore = [&](int endExclusive) -> QPair<int, int> {
+        int bestStart = -1;
+        int bestEnd = -1;
+        int scanPos = rangeStart;
+        while (scanPos < endExclusive) {
+            const QPair<int, int> found = editor->findText(static_cast<int>(flags), needleBytes.constData(), scanPos, endExclusive);
+            if (found.first < 0 || found.first >= endExclusive) {
+                break;
+            }
+            bestStart = found.first;
+            bestEnd = found.second;
+            scanPos = found.first + 1;
+        }
+        return QPair<int, int>(bestStart, bestEnd);
+    };
+
+    QPair<int, int> found = findLastBefore(caretBase);
+    if (found.first >= 0) {
+        selectMatch(found.first, found.second);
+        return true;
+    }
+
+    if (m_findReplaceDialog->wrapAround()) {
+        found = findLastBefore(rangeEnd);
+        if (found.first >= 0) {
+            selectMatch(found.first, found.second);
+            return true;
+        }
+    }
+
+    showNotFound();
+    return false;
+}
+
+bool MainWindow::replaceOneInCurrentEditor(bool showNotFoundMessage)
+{
+    SciEdit *editor = m_tabWidget->currentEditor();
+    if (!editor) {
+        return false;
+    }
+    if (!m_findReplaceDialog) {
+        m_findReplaceDialog = new FindReplaceDialog(this);
+        connect(m_findReplaceDialog, &FindReplaceDialog::findRequested, this, [this](bool forward) {
+            findNextInCurrentEditor(forward, true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceRequested, this, [this]() {
+            replaceOneInCurrentEditor(true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceAllRequested, this, [this]() {
+            replaceAllInCurrentEditor(true);
+        });
+    }
+
+    const QString needle = buildFindPattern(m_findReplaceDialog);
+    if (needle.isEmpty()) {
+        return false;
+    }
+
+    if (!findNextInCurrentEditor(true, showNotFoundMessage)) {
+        return false;
+    }
+
+    const QString replacement = buildReplacementText(m_findReplaceDialog);
+    const QByteArray replacementBytes = replacement.toUtf8();
+
+    editor->targetFromSelection();
+    if (m_findReplaceDialog->searchMode() == SearchMode::Regex) {
+        editor->replaceTargetRE(replacementBytes.size(), replacementBytes.constData());
+    } else {
+        editor->replaceTarget(replacementBytes.size(), replacementBytes.constData());
+    }
+
+    findNextInCurrentEditor(true, false);
+    return true;
+}
+
+int MainWindow::replaceAllInCurrentEditor(bool showNotFoundMessage)
+{
+    SciEdit *editor = m_tabWidget->currentEditor();
+    if (!editor) {
+        return 0;
+    }
+    if (!m_findReplaceDialog) {
+        m_findReplaceDialog = new FindReplaceDialog(this);
+        connect(m_findReplaceDialog, &FindReplaceDialog::findRequested, this, [this](bool forward) {
+            findNextInCurrentEditor(forward, true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceRequested, this, [this]() {
+            replaceOneInCurrentEditor(true);
+        });
+        connect(m_findReplaceDialog, &FindReplaceDialog::replaceAllRequested, this, [this]() {
+            replaceAllInCurrentEditor(true);
+        });
+    }
+
+    const QString needle = buildFindPattern(m_findReplaceDialog);
+    if (needle.isEmpty()) {
+        return 0;
+    }
+
+    const QByteArray needleBytes = needle.toUtf8();
+    const QString replacement = buildReplacementText(m_findReplaceDialog);
+    const QByteArray replacementBytes = replacement.toUtf8();
+    const sptr_t flags = buildSearchFlags(m_findReplaceDialog);
+
+    const int docLen = static_cast<int>(editor->textLength());
+    int rangeStart = 0;
+    int rangeEnd = docLen;
+
+    if (m_findReplaceDialog->inSelection()) {
+        if (!m_findInSelectionEnabled) {
+            const int selStart = static_cast<int>(editor->selectionStart());
+            const int selEnd = static_cast<int>(editor->selectionEnd());
+            if (selStart != selEnd) {
+                m_findSelectionStart = qMin(selStart, selEnd);
+                m_findSelectionEnd = qMax(selStart, selEnd);
+                m_findInSelectionEnabled = true;
+            }
+        }
+    } else {
+        m_findInSelectionEnabled = false;
+    }
+
+    if (m_findInSelectionEnabled) {
+        rangeStart = qBound(0, m_findSelectionStart, docLen);
+        rangeEnd = qBound(0, m_findSelectionEnd, docLen);
+        if (rangeStart >= rangeEnd) {
+            m_findInSelectionEnabled = false;
+            rangeStart = 0;
+            rangeEnd = docLen;
+        }
+    }
+
+    editor->setSearchFlags(flags);
+
+    int replacedCount = 0;
+    int start = rangeStart;
+    int end = rangeEnd;
+
+    editor->beginUndoAction();
+    while (start <= end) {
+        editor->setTargetRange(start, end);
+        const sptr_t pos = editor->searchInTarget(needleBytes.size(), needleBytes.constData());
+        if (pos < 0) {
+            break;
+        }
+
+        const int matchStart = static_cast<int>(editor->targetStart());
+        const int matchEnd = static_cast<int>(editor->targetEnd());
+        const int matchLen = matchEnd - matchStart;
+
+        sptr_t replacedLen = 0;
+        if (m_findReplaceDialog->searchMode() == SearchMode::Regex) {
+            replacedLen = editor->replaceTargetRE(replacementBytes.size(), replacementBytes.constData());
+        } else {
+            replacedLen = editor->replaceTarget(replacementBytes.size(), replacementBytes.constData());
+        }
+
+        ++replacedCount;
+        const int delta = static_cast<int>(replacedLen) - matchLen;
+        end += delta;
+        start = matchStart + static_cast<int>(replacedLen);
+    }
+    editor->endUndoAction();
+
+    if (replacedCount == 0 && showNotFoundMessage) {
+        QMessageBox::information(this, QStringLiteral("Replace"), QStringLiteral("Text not found."));
+    }
+
+    return replacedCount;
+}
diff --git a/mainwindow.h b/mainwindow.h
index dc98f44..2877c1b 100644
--- a/mainwindow.h
+++ b/mainwindow.h
@@ -8,6 +8,7 @@ class QLabel;
 class SciEdit;
 class TabWidget;
 class DocumentManager;
+class FindReplaceDialog;
 
 class MainWindow : public KXmlGuiWindow
 {
@@ -36,6 +37,10 @@ private:
     void updateWindowTitle();
     void updateStatusBar();
     void updateActions();
+    void showFindReplaceDialog(bool showReplace);
+    bool findNextInCurrentEditor(bool forward, bool showNotFoundMessage);
+    bool replaceOneInCurrentEditor(bool showNotFoundMessage);
+    int replaceAllInCurrentEditor(bool showNotFoundMessage);
 
     DocumentManager *m_documentManager;
     TabWidget *m_tabWidget;
@@ -43,6 +48,10 @@ private:
     QLabel *m_encodingStatusLabel;
     QLabel *m_languageStatusLabel;
     bool m_indentGuidesEnabled = false;
+    FindReplaceDialog *m_findReplaceDialog = nullptr;
+    bool m_findInSelectionEnabled = false;
+    int m_findSelectionStart = 0;
+    int m_findSelectionEnd = 0;
 };
 
 // plainly for KConfigDialog