diff --git a/re/fuzzingwindow.cpp b/re/fuzzingwindow.cpp
index d7c84a4..9a75c3e 100644
--- a/re/fuzzingwindow.cpp
+++ b/re/fuzzingwindow.cpp
@@ -19,6 +19,9 @@ FuzzingWindow::FuzzingWindow(const QVector<CANFrame> *frames, QWidget *parent) :
 
     fuzzTimer = new QTimer();
 
+    connect(ui->btnMarkAllHigh, &QPushButton::clicked, this, &FuzzingWindow::markAllHigh);
+    connect(ui->btnMarkAllLow, &QPushButton::clicked, this, &FuzzingWindow::markAllLow);
+    connect(ui->btnMarkAllAuto, &QPushButton::clicked, this, &FuzzingWindow::markAllAuto);
     connect(ui->btnStartStop, &QPushButton::clicked, this, &FuzzingWindow::toggleFuzzing);
     connect(ui->btnAllFilters, &QPushButton::clicked, this, &FuzzingWindow::setAllFilters);
     connect(ui->btnNoFilters, &QPushButton::clicked, this, &FuzzingWindow::clearAllFilters);
@@ -508,3 +511,30 @@ void FuzzingWindow::redrawGrid()
     ui->bitfield->setReference(refBytes, false);
     ui->bitfield->updateData(dataBytes, true);
 }
+
+void FuzzingWindow::markAllHigh()
+{
+    for (int i = 0; i < 512; i++)
+    {
+        bitGrid[i] = 2;
+    }
+    redrawGrid();
+}
+
+void FuzzingWindow::markAllLow()
+{
+    for (int i = 0; i < 512; i++)
+    {
+        bitGrid[i] = 0;
+    }
+    redrawGrid();
+}
+
+void FuzzingWindow::markAllAuto()
+{
+    for (int i = 0; i < 512; i++)
+    {
+        bitGrid[i] = 1;
+    }
+    redrawGrid();
+}
diff --git a/re/fuzzingwindow.h b/re/fuzzingwindow.h
index 6b52da4..58cf378 100644
--- a/re/fuzzingwindow.h
+++ b/re/fuzzingwindow.h
@@ -42,6 +42,9 @@ private slots:
     void bitfieldClicked(int);
     void changedNumDataBytes(int newVal);
     void updatedFrames(int numFrames);
+    void markAllHigh();
+    void markAllLow();
+    void markAllAuto();
 
 private:
     Ui::FuzzingWindow *ui;
diff --git a/ui/fuzzingwindow.ui b/ui/fuzzingwindow.ui
index 1600b97..813e9a4 100644
--- a/ui/fuzzingwindow.ui
+++ b/ui/fuzzingwindow.ui
@@ -487,6 +487,27 @@
      </property>
     </widget>
    </item>
+   <item>
+    <widget class="QPushButton" name="btnMarkAllHigh">
+     <property name="text">
+      <string>All High</string>
+     </property>
+    </widget>
+    </item>
+    <item>
+    <widget class="QPushButton" name="btnMarkAllLow">
+     <property name="text">
+      <string>All Low</string>
+     </property>
+    </widget>
+    </item>
+    <item>
+    <widget class="QPushButton" name="btnMarkAllAuto">
+     <property name="text">
+      <string>All Auto</string>
+     </property>
+    </widget>
+   </item>
    <item>
     <widget class="QPushButton" name="btnStartStop">
      <property name="text">
@@ -534,6 +555,9 @@
   <tabstop>listID</tabstop>
   <tabstop>btnAllFilters</tabstop>
   <tabstop>btnNoFilters</tabstop>
+  <tabstop>btnMarkAllHigh</tabstop>
+  <tabstop>btnMarkAllLow</tabstop>
+  <tabstop>btnMarkAllAuto</tabstop>
   <tabstop>btnStartStop</tabstop>
  </tabstops>
  <resources/>