diff --git a/src/Kaleidoscope-HardwareTestMode.h b/src/Kaleidoscope-HardwareTestMode.h
new file mode 100644
index 00000000..8e7a8811
--- /dev/null
+++ b/src/Kaleidoscope-HardwareTestMode.h
@@ -0,0 +1,19 @@
+/* Kaleidoscope-Hardware-TestMode - A factory test mode for the Model 01.
+ * Copyright (C) 2017-2019  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include "kaleidoscope/plugin/HardwareTestMode.h"
diff --git a/src/kaleidoscope/Hardware.h b/src/kaleidoscope/Hardware.h
index 35a303a4..0f275f0d 100644
--- a/src/kaleidoscope/Hardware.h
+++ b/src/kaleidoscope/Hardware.h
@@ -253,6 +253,40 @@ class Hardware {
     return 0;
   }
 
+  /**
+   * Check if a key was pressed at a given position on the previous scan
+   *
+   * @param row is the row the key is located at in the matrix.
+   * @param col is the column the key is located at in the matrix.
+   *
+   * @returns true if the key was pressed, false otherwise.
+   */
+  bool wasKeyswitchPressed(byte row, byte col) {
+    return false;
+  }
+  /**
+   * Check if a key was pressed at a given position on the previous scan.
+   *
+   * @param keyIndex is the key index, as calculated by `keyIndex`.
+   *
+   * @note Key indexes start at 1, not 0!
+   *
+   * @returns true if the key was pressed, false otherwise.
+   */
+  bool wasKeyswitchPressed(uint8_t keyIndex) {
+    return false;
+  }
+
+  /**
+   * Check the number of key switches pressed in the previous scan.
+   *
+   * @returns the number of keys pressed.
+   */
+  uint8_t previousPressedKeyswitchCount() {
+    return 0;
+  }
+
+
   /** @} */
 
   /**
@@ -266,6 +300,16 @@ class Hardware {
    * bring it up into a useful state.
    */
   void setup() {}
+
+  /**
+   * Method to configure the device for a hardware test mode
+   *
+   * Called by the Kaleidoscope Hardware test plugin, this method should
+   * do any device-specific initialization needed for factory hardware testing
+   *
+   */
+  void enableHardwareTestMode() {}
+
   /** @} */
 };
 }
diff --git a/src/kaleidoscope/hardware/ATMegaKeyboard.cpp b/src/kaleidoscope/hardware/ATMegaKeyboard.cpp
index 724319e8..b3801d2a 100644
--- a/src/kaleidoscope/hardware/ATMegaKeyboard.cpp
+++ b/src/kaleidoscope/hardware/ATMegaKeyboard.cpp
@@ -85,6 +85,28 @@ bool ATMegaKeyboard::isKeyswitchPressed(uint8_t keyIndex) {
                             keyIndex % KeyboardHardware.matrix_columns);
 }
 
+
+uint8_t ATMegaKeyboard::previousPressedKeyswitchCount() {
+  uint8_t count = 0;
+
+  for (int8_t r = 0; r < KeyboardHardware.matrix_rows; r++) {
+    count += __builtin_popcount(KeyboardHardware.previousKeyState_[r]);
+  }
+  return count;
+}
+
+bool ATMegaKeyboard::wasKeyswitchPressed(uint8_t row, byte col) {
+  return (bitRead(KeyboardHardware.previousKeyState_[row], col) != 0);
+
+}
+
+bool ATMegaKeyboard::wasKeyswitchPressed(uint8_t keyIndex) {
+  keyIndex--;
+  return wasKeyswitchPressed(keyIndex / KeyboardHardware.matrix_columns,
+                             keyIndex % KeyboardHardware.matrix_columns);
+}
+
+
 void __attribute__((optimize(3))) ATMegaKeyboard::actOnMatrixScan() {
   for (byte row = 0; row < KeyboardHardware.matrix_rows; row++) {
     for (byte col = 0; col < KeyboardHardware.matrix_columns; col++) {
diff --git a/src/kaleidoscope/hardware/ATMegaKeyboard.h b/src/kaleidoscope/hardware/ATMegaKeyboard.h
index 32191883..079ba0c2 100644
--- a/src/kaleidoscope/hardware/ATMegaKeyboard.h
+++ b/src/kaleidoscope/hardware/ATMegaKeyboard.h
@@ -87,6 +87,10 @@ class ATMegaKeyboard : public kaleidoscope::Hardware {
   bool isKeyswitchPressed(uint8_t row, byte col);
   bool isKeyswitchPressed(uint8_t keyIndex);
 
+  uint8_t previousPressedKeyswitchCount();
+  bool wasKeyswitchPressed(uint8_t row, byte col);
+  bool wasKeyswitchPressed(uint8_t keyIndex);
+
   void maskKey(byte row, byte col);
   void unMaskKey(byte row, byte col);
   bool isKeyMasked(byte row, byte col);
diff --git a/src/kaleidoscope/hardware/ez/ErgoDox.cpp b/src/kaleidoscope/hardware/ez/ErgoDox.cpp
index b5228780..b7d87a0c 100644
--- a/src/kaleidoscope/hardware/ez/ErgoDox.cpp
+++ b/src/kaleidoscope/hardware/ez/ErgoDox.cpp
@@ -232,6 +232,24 @@ bool ErgoDox::isKeyswitchPressed(uint8_t keyIndex) {
   return isKeyswitchPressed(keyIndex / COLS, keyIndex % COLS);
 }
 
+bool ErgoDox::wasKeyswitchPressed(byte row, byte col) {
+  return (bitRead(previousKeyState_[row], col) != 0);
+}
+
+bool ErgoDox::wasKeyswitchPressed(uint8_t keyIndex) {
+  keyIndex--;
+  return wasKeyswitchPressed(keyIndex / COLS, keyIndex % COLS);
+}
+
+uint8_t ErgoDox::previousPressedKeyswitchCount() {
+  uint8_t count = 0;
+
+  for (uint8_t r = 0; r < ROWS; r++) {
+    count += __builtin_popcount(previousKeyState_[r]);
+  }
+  return count;
+}
+
 uint8_t ErgoDox::pressedKeyswitchCount() {
   uint8_t count = 0;
 
diff --git a/src/kaleidoscope/hardware/ez/ErgoDox.h b/src/kaleidoscope/hardware/ez/ErgoDox.h
index 87249560..ec2da2bb 100644
--- a/src/kaleidoscope/hardware/ez/ErgoDox.h
+++ b/src/kaleidoscope/hardware/ez/ErgoDox.h
@@ -69,6 +69,10 @@ class ErgoDox : public kaleidoscope::Hardware {
   bool isKeyswitchPressed(uint8_t keyIndex);
   uint8_t pressedKeyswitchCount();
 
+  bool wasKeyswitchPressed(byte row, byte col);
+  bool wasKeyswitchPressed(uint8_t keyIndex);
+  uint8_t previousPressedKeyswitchCount();
+
   // ErgoDox-specific stuff
   void setStatusLED(uint8_t led, bool state = true);
   void setStatusLEDBrightness(uint8_t led, uint8_t brightness);
diff --git a/src/kaleidoscope/hardware/keyboardio/Model01.cpp b/src/kaleidoscope/hardware/keyboardio/Model01.cpp
index 0db65458..55a697bc 100644
--- a/src/kaleidoscope/hardware/keyboardio/Model01.cpp
+++ b/src/kaleidoscope/hardware/keyboardio/Model01.cpp
@@ -85,6 +85,17 @@ void Model01::setup(void) {
   TWBR = 12; // This is 400mhz, which is the fastest we can drive the ATTiny
 }
 
+void Model01::enableHardwareTestMode() {
+
+  // Toggle the programming LEDS on
+  PORTD |= (1 << 5);
+  PORTB |= (1 << 0);
+
+  // Disable the debouncer on the ATTinys
+  KeyboardHardware.setKeyscanInterval(2);
+}
+
+
 
 void Model01::setCrgbAt(int8_t i, cRGB crgb) {
   if (i < 0) {
@@ -305,10 +316,28 @@ bool Model01::isKeyswitchPressed(uint8_t keyIndex) {
   return isKeyswitchPressed(keyIndex / COLS, keyIndex % COLS);
 }
 
+
+bool Model01::wasKeyswitchPressed(byte row, byte col) {
+  if (col <= 7) {
+    return (bitRead(previousLeftHandState.rows[row], 7 - col) != 0);
+  } else {
+    return (bitRead(previousRightHandState.rows[row], 7 - (col - 8)) != 0);
+  }
+}
+
+bool Model01::wasKeyswitchPressed(uint8_t keyIndex) {
+  keyIndex--;
+  return wasKeyswitchPressed(keyIndex / COLS, keyIndex % COLS);
+}
+
 uint8_t Model01::pressedKeyswitchCount() {
   return __builtin_popcountl(leftHandState.all) + __builtin_popcountl(rightHandState.all);
 }
 
+uint8_t Model01::previousPressedKeyswitchCount() {
+  return __builtin_popcountl(previousLeftHandState.all) + __builtin_popcountl(previousRightHandState.all);
+}
+
 }
 }
 }
diff --git a/src/kaleidoscope/hardware/keyboardio/Model01.h b/src/kaleidoscope/hardware/keyboardio/Model01.h
index 5457f87b..60112673 100644
--- a/src/kaleidoscope/hardware/keyboardio/Model01.h
+++ b/src/kaleidoscope/hardware/keyboardio/Model01.h
@@ -72,6 +72,12 @@ class Model01 : public kaleidoscope::Hardware {
   bool isKeyswitchPressed(uint8_t keyIndex);
   uint8_t pressedKeyswitchCount();
 
+  bool wasKeyswitchPressed(byte row, byte col);
+  bool wasKeyswitchPressed(uint8_t keyIndex);
+  uint8_t previousPressedKeyswitchCount();
+
+  void enableHardwareTestMode();
+
   keydata_t leftHandState;
   keydata_t rightHandState;
   keydata_t previousLeftHandState;
diff --git a/src/kaleidoscope/plugin/HardwareTestMode.cpp b/src/kaleidoscope/plugin/HardwareTestMode.cpp
new file mode 100644
index 00000000..04aece10
--- /dev/null
+++ b/src/kaleidoscope/plugin/HardwareTestMode.cpp
@@ -0,0 +1,129 @@
+/* Kaleidoscope-HardwareTestMode - A factory test mode for the Model 01.
+ * Copyright (C) 2017-2019  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "Kaleidoscope.h"
+#include "Kaleidoscope-HardwareTestMode.h"
+#include "Kaleidoscope-LEDEffect-Rainbow.h"
+
+namespace kaleidoscope {
+namespace plugin {
+
+
+constexpr uint8_t CHATTER_CYCLE_LIMIT = 30;
+
+uint8_t HardwareTestMode::actionKey;
+
+void HardwareTestMode::setActionKey(uint8_t key) {
+  actionKey = key;
+}
+
+void HardwareTestMode::waitForKeypress() {
+  while (1) {
+    KeyboardHardware.readMatrix();
+    if (KeyboardHardware.isKeyswitchPressed(actionKey) &&
+        ! KeyboardHardware.wasKeyswitchPressed(actionKey)) {
+      break;
+    }
+  }
+}
+
+void HardwareTestMode::setLeds(cRGB color) {
+  ::LEDControl.set_all_leds_to(color);
+  ::LEDControl.syncLeds();
+  waitForKeypress();
+}
+
+void HardwareTestMode::testLeds(void) {
+  constexpr cRGB red = CRGB(201, 0, 0);
+  constexpr cRGB blue = CRGB(0, 0, 201);
+  constexpr cRGB green = CRGB(0, 201, 0);
+  constexpr cRGB brightWhite = CRGB(160, 160, 160);
+
+  setLeds(brightWhite);
+  setLeds(blue);
+  setLeds(green);
+  setLeds(red);
+  // rainbow for 10 seconds
+  ::LEDRainbowEffect.update_delay(5);
+  for (auto i = 0; i < 300; i++) {
+    ::LEDRainbowEffect.update();
+    ::LEDControl.syncLeds();
+  }
+}
+
+
+
+void HardwareTestMode::testMatrix() {
+  // Reset bad keys from previous tests.
+  chatter_data state[KeyboardHardware.matrix_columns * KeyboardHardware.matrix_rows] = {0, 0, 0};
+
+  constexpr cRGB red = CRGB(201, 0, 0);
+  constexpr cRGB blue = CRGB(0, 0, 201);
+  constexpr cRGB green = CRGB(0, 201, 0);
+  constexpr cRGB yellow = CRGB(201, 100, 0);
+
+  while (1) {
+    KeyboardHardware.readMatrix();
+    for (byte row = 0; row < KeyboardHardware.matrix_rows; row++) {
+      for (byte col = 0; col < KeyboardHardware.matrix_columns; col++) {
+        uint8_t keynum = (row * KeyboardHardware.matrix_columns) + (col);
+
+        // If the key is toggled on
+        if (KeyboardHardware.isKeyswitchPressed(row, col) && ! KeyboardHardware.wasKeyswitchPressed(row, col)) {
+          // And it's too soon (in terms of cycles between changes)
+          state[keynum].tested = 1;
+          if (state[keynum].cyclesSinceStateChange < CHATTER_CYCLE_LIMIT) {
+            state[keynum].bad = 1;
+          }
+          state[keynum].cyclesSinceStateChange = 0;
+        } else if (state[keynum].cyclesSinceStateChange < CHATTER_CYCLE_LIMIT) {
+          state[keynum].cyclesSinceStateChange++;
+        }
+        // If the key is held down
+        if (KeyboardHardware.isKeyswitchPressed(row, col) && KeyboardHardware.wasKeyswitchPressed(row, col)) {
+          KeyboardHardware.setCrgbAt(row, col, green);
+        }
+
+        // If we triggered chatter detection ever on this key
+        else if (state[keynum].bad == 1) {
+          KeyboardHardware.setCrgbAt(row, col, red);
+        } else if (state[keynum].tested == 0) {
+          KeyboardHardware.setCrgbAt(row, col, yellow);
+        }
+        // If the key is not currently pressed and was not just released and is not marked bad
+        else if (! KeyboardHardware.isKeyswitchPressed(row, col)) {
+          KeyboardHardware.setCrgbAt(row, col, blue);
+        }
+      }
+    }
+    ::LEDControl.syncLeds();
+  }
+}
+
+void HardwareTestMode::runTests() {
+  // When we start test mode, we -may- have some keys held, so empty it
+  // out and send a new report
+  kaleidoscope::hid::releaseAllKeys();
+  kaleidoscope::hid::sendKeyboardReport();
+  KeyboardHardware.enableHardwareTestMode();
+  testLeds();
+  testMatrix();
+}
+
+}
+}
+
+kaleidoscope::plugin::HardwareTestMode HardwareTestMode;
diff --git a/src/kaleidoscope/plugin/HardwareTestMode.h b/src/kaleidoscope/plugin/HardwareTestMode.h
new file mode 100644
index 00000000..65ab36e4
--- /dev/null
+++ b/src/kaleidoscope/plugin/HardwareTestMode.h
@@ -0,0 +1,49 @@
+/* Kaleidoscope-HardwareTestMode - A factory test mode for the Model 01.
+ * Copyright (C) 2017-2019  Keyboard.io, Inc.
+ *
+ * This program is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License as published by the Free Software
+ * Foundation, version 3.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <Arduino.h>
+#include "Kaleidoscope.h"
+
+namespace kaleidoscope {
+namespace plugin {
+
+class HardwareTestMode : public kaleidoscope::Plugin {
+ public:
+
+  typedef struct {
+    uint8_t bad : 1,
+            tested : 1,
+            cyclesSinceStateChange: 6;
+  } chatter_data;
+  static uint8_t actionKey;
+
+  HardwareTestMode(void) {}
+
+  static void runTests();
+  static void setActionKey(uint8_t key);
+ private:
+  static void testLeds();
+  static void testMatrix();
+  static void toggleProgrammingLedsOn();
+  static void waitForKeypress();
+  static void setLeds(cRGB color);
+};
+}
+}
+
+extern kaleidoscope::plugin::HardwareTestMode HardwareTestMode;