diff --git a/src/main/scala/com/melvic/chi/Config.scala b/src/main/scala/com/melvic/chi/Config.scala
index f132e46..ed79027 100644
--- a/src/main/scala/com/melvic/chi/Config.scala
+++ b/src/main/scala/com/melvic/chi/Config.scala
@@ -3,8 +3,8 @@ package com.melvic.chi
 // TODO: Store this on a properties file
 object Config {
   val MaxColumnWidth: Int = 80
-  val DialogFontSize: Int = 14
-  val DialogHeaderFontSize: Int = 15
+  val ComponentFontSize: Float = 14
+  val ComponentHeaderFontSize: Int = 15
   val CustomSettingsPath = "user-prefs.json"
   val DefaultSettingsPath = "preferences.json"
   val DefaultFontPath = "/fonts/FiraCode-Regular.ttf"
diff --git a/src/main/scala/com/melvic/chi/config/Preferences.scala b/src/main/scala/com/melvic/chi/config/Preferences.scala
index cd6e66e..dc83498 100644
--- a/src/main/scala/com/melvic/chi/config/Preferences.scala
+++ b/src/main/scala/com/melvic/chi/config/Preferences.scala
@@ -23,4 +23,9 @@ object Preferences {
   def loadDefaults: Preferences = new Preferences {
     content = SettingsContent.loadDefaults
   }
+
+  def fromContent(settingsContent: SettingsContent): Preferences =
+    new Preferences {
+      content = settingsContent
+    }
 }
diff --git a/src/main/scala/com/melvic/chi/eval/package.scala b/src/main/scala/com/melvic/chi/eval/package.scala
index c5d94fb..c32523c 100644
--- a/src/main/scala/com/melvic/chi/eval/package.scala
+++ b/src/main/scala/com/melvic/chi/eval/package.scala
@@ -1,11 +1,18 @@
 package com.melvic.chi
 
+import com.melvic.chi.ast.Definition
 import com.melvic.chi.config.Preferences
 import com.melvic.chi.out.Result
 
 package object eval {
   type Evaluate = String => String
 
-  def generateAndShow(code: String)(implicit prefs: Preferences): String =
-    Result.show(Generate.fromSignatureString(code))
+  def generateWith(code: String)(f: Result[Definition] => String)(implicit prefs: Preferences): String =
+    f(Generate.fromSignatureString(code))
+
+  def generateAndShowWithInfo(code: String)(implicit prefs: Preferences): String =
+    generateWith(code)(Result.showWithInfo)
+
+  def generateAndShowCode(code: String)(implicit prefs: Preferences): String =
+    generateWith(code)(Result.showCode)
 }
diff --git a/src/main/scala/com/melvic/chi/package.scala b/src/main/scala/com/melvic/chi/package.scala
index 722f871..8c9813b 100644
--- a/src/main/scala/com/melvic/chi/package.scala
+++ b/src/main/scala/com/melvic/chi/package.scala
@@ -7,5 +7,5 @@ package object chi {
   type Result[A] = Result.Result[A]
   type Evaluate = eval.Evaluate
 
-  def generateAndShow(code: String)(implicit prefs: Preferences): String = eval.generateAndShow(code)
+  def generateAndShow(code: String)(implicit prefs: Preferences): String = eval.generateAndShowWithInfo(code)
 }
diff --git a/src/main/scala/com/melvic/chi/views/FontUtils.scala b/src/main/scala/com/melvic/chi/views/FontUtils.scala
index 3aa1a66..e4d5788 100644
--- a/src/main/scala/com/melvic/chi/views/FontUtils.scala
+++ b/src/main/scala/com/melvic/chi/views/FontUtils.scala
@@ -1,6 +1,8 @@
 package com.melvic.chi.views
 
-import java.awt.Component
+import com.melvic.chi.Config
+
+import java.awt.{Component, Font}
 
 object FontUtils {
   def updateSize[C <: Component](component: C, size: Float): C =
@@ -17,4 +19,10 @@ object FontUtils {
     component.setFont(newFont)
     component
   }
+
+  def withComponentFont[C <: Component](component: C): C =
+    updateSize(component, Config.ComponentFontSize)
+
+  def withComponentHeaderFont[C <: Component](component: C) =
+    updateStyle(updateSize(component, Config.ComponentHeaderFontSize), Font.BOLD)
 }
diff --git a/src/main/scala/com/melvic/chi/views/MainWindow.scala b/src/main/scala/com/melvic/chi/views/MainWindow.scala
index 65fac3b..ec16074 100644
--- a/src/main/scala/com/melvic/chi/views/MainWindow.scala
+++ b/src/main/scala/com/melvic/chi/views/MainWindow.scala
@@ -2,6 +2,7 @@ package com.melvic.chi.views
 
 import com.melvic.chi.Evaluate
 import com.melvic.chi.config.Preferences
+import com.melvic.chi.views.dialogs.PreferencesDialog
 import com.melvic.chi.views.menus.MenuBar
 
 import java.awt._
diff --git a/src/main/scala/com/melvic/chi/views/ToolBarComponent.scala b/src/main/scala/com/melvic/chi/views/ToolBarComponent.scala
index 8a7b32a..66cc0a9 100644
--- a/src/main/scala/com/melvic/chi/views/ToolBarComponent.scala
+++ b/src/main/scala/com/melvic/chi/views/ToolBarComponent.scala
@@ -1,14 +1,18 @@
 package com.melvic.chi.views
 
 import com.melvic.chi.Config
+import com.melvic.chi.views.dialogs.PreferencesDialog
 
+import java.awt.Dimension
 import java.awt.event.ActionListener
 import javax.swing.{ImageIcon, JButton, JToolBar}
 
-class ToolBarComponent(editorComponent: EditorComponent, preferencesDialog: PreferencesDialog) extends JToolBar {
-  add(makeButton("run", "Run code", "Run", _ => editorComponent.run()))
-  add(makeButton("clear", "Clear all text", "Clear", _ => editorComponent.clear()))
+class ToolBarComponent(editorComponent: EditorComponent, preferencesDialog: PreferencesDialog)
+    extends JToolBar {
   add(makeButton("preferences", "Show Preferences", "Preferences", _ => preferencesDialog.display()))
+  addSeparator(new Dimension(20, 10))
+  add(makeButton("run", "Run code", "Run", _ => editorComponent.run()))
+  add(makeButton("clear", "Clear all texts", "Clear", _ => editorComponent.clear()))
 
   private def makeButton(
       imageName: String,
@@ -23,10 +27,10 @@ class ToolBarComponent(editorComponent: EditorComponent, preferencesDialog: Pref
     val imageURL = getClass.getResource(Config.IconsDir + imageName + ".png")
     if (imageURL != null)
       button.setIcon(new ImageIcon(imageURL, altText))
-    else {
-      button.setText(altText)
+    else
       System.err.println("Icon not found: " + imageName)
-    }
+
+    button.setText(altText)
 
     button
   }
diff --git a/src/main/scala/com/melvic/chi/views/PreferencesDialog.scala b/src/main/scala/com/melvic/chi/views/dialogs/PreferencesDialog.scala
similarity index 67%
rename from src/main/scala/com/melvic/chi/views/PreferencesDialog.scala
rename to src/main/scala/com/melvic/chi/views/dialogs/PreferencesDialog.scala
index 716eae7..6dbd290 100644
--- a/src/main/scala/com/melvic/chi/views/PreferencesDialog.scala
+++ b/src/main/scala/com/melvic/chi/views/dialogs/PreferencesDialog.scala
@@ -1,15 +1,16 @@
-package com.melvic.chi.views
+package com.melvic.chi.views.dialogs
 
-import com.melvic.chi.Config
 import com.melvic.chi.config.SettingsContent.ScalaSettings
 import com.melvic.chi.config.{Preferences, SettingsContent}
+import com.melvic.chi.views.FontUtils
 import net.miginfocom.swing.MigLayout
 
-import java.awt.{Font, Frame}
+import java.awt.Frame
+import java.awt.event.{ActionEvent, ActionListener, ItemEvent, ItemListener}
 import javax.swing._
+import scala.Function.const
 
-class PreferencesDialog(frame: Frame)(implicit preferences: Preferences)
-    extends JDialog(frame, true) {
+class PreferencesDialog(frame: Frame)(implicit preferences: Preferences) extends JDialog(frame, true) {
   setTitle("Preferences")
 
   val pointFreeBox = createCheckBox("Point-free style")
@@ -83,20 +84,40 @@ class PreferencesDialog(frame: Frame)(implicit preferences: Preferences)
     addTitle("Scala Settings", scalaPane)
     checkBoxes.foreach(scalaPane.add(_, "wrap"))
 
+    val previewComponent = PreviewComponent.fromPanel(scalaPane)
+    addCheckBoxListeners(previewComponent)
     scalaPane
   }
 
   private def createCheckBox(text: String): JCheckBox =
-    FontUtils.updateSize(new JCheckBox(text), Config.DialogFontSize)
+    FontUtils.withComponentFont(new JCheckBox(text))
 
   private def addTitle(title: String, panel: JPanel): Unit = {
     panel.add(
-      FontUtils.updateStyle(
-        FontUtils.updateSize(new JLabel(title), Config.DialogHeaderFontSize),
-        Font.BOLD
-      ),
+      FontUtils.withComponentHeaderFont(new JLabel(title)),
       "gapleft 20, wrap"
     )
     panel.add(new JSeparator(), "growx, wrap, gapbottom 20")
   }
+
+  private def addCheckBoxListeners(previewComponent: PreviewComponent): Unit = {
+    def rerunPreview(): Unit = {
+      val scalaSettings = preferences.content.scala
+      val newScalaSettings = scalaSettings.copy(
+        pointFree = pointFreeBox.isSelected,
+        simplifyMatch = simplifyMatchBox.isSelected,
+        usePredef = usePredefBox.isSelected
+      )
+      val newPreferences = Preferences.fromContent(SettingsContent(newScalaSettings))
+      println(newScalaSettings)
+      previewComponent.run(newPreferences)
+    }
+
+    pointFreeBox.addActionListener(_ => rerunPreview())
+    pointFreeBox.addItemListener(_ => rerunPreview())
+    simplifyMatchBox.addActionListener(_ => rerunPreview())
+    simplifyMatchBox.addItemListener(_ => rerunPreview())
+    usePredefBox.addActionListener(_ => rerunPreview())
+    usePredefBox.addItemListener(_ => rerunPreview())
+  }
 }
diff --git a/src/main/scala/com/melvic/chi/views/dialogs/PreviewComponent.scala b/src/main/scala/com/melvic/chi/views/dialogs/PreviewComponent.scala
new file mode 100644
index 0000000..baec277
--- /dev/null
+++ b/src/main/scala/com/melvic/chi/views/dialogs/PreviewComponent.scala
@@ -0,0 +1,47 @@
+package com.melvic.chi.views.dialogs
+
+import com.melvic.chi.config.Preferences
+import com.melvic.chi.eval.generateAndShowCode
+import com.melvic.chi.views.{FontUtils, TextAreaComponent}
+import org.fife.ui.rtextarea.RTextScrollPane
+
+import java.awt.Font
+import javax.swing.{JLabel, JPanel}
+
+class PreviewComponent(implicit prefs: Preferences) extends RTextScrollPane(new TextAreaComponent) {
+  val textArea = getTextArea
+  textArea.setEditable(false)
+  textArea.setColumns(70)
+  textArea.setRows(20)
+  FontUtils.withComponentFont(textArea)
+
+  val inputs = List(
+    "def compose[A, B, C](f: B => C, g: A => B): A => C",
+    "def disjunctionElimination[A, B, C](f: A => C, g: B => C): Either[A, B] => C",
+    "def id[A]: A => A",
+    "def identity[A]: A => A"
+  )
+
+  run(prefs)
+
+  def run(preferences: Preferences): Unit = {
+    val output = inputs.map(generateAndShowCode(_)(preferences)).mkString("\n\n")
+    textArea.setText(output)
+  }
+}
+
+object PreviewComponent {
+  def fromPanel(panel: JPanel, extraLabelConstraints: String = "gaptop 20")(
+      implicit prefs: Preferences
+  ): PreviewComponent = {
+    val label = new JLabel("Preview:")
+    val fullLabelConstraints = "wrap" +
+      (if (extraLabelConstraints.nonEmpty) s", $extraLabelConstraints" else "")
+    FontUtils.withComponentFont(FontUtils.updateStyle(label, Font.BOLD))
+
+    val previewComponent = new PreviewComponent()
+    panel.add(label, fullLabelConstraints)
+    panel.add(previewComponent, "wrap")
+    previewComponent
+  }
+}
diff --git a/src/main/scala/com/melvic/chi/views/menus/FileMenu.scala b/src/main/scala/com/melvic/chi/views/menus/FileMenu.scala
index bc7c52c..0514c85 100644
--- a/src/main/scala/com/melvic/chi/views/menus/FileMenu.scala
+++ b/src/main/scala/com/melvic/chi/views/menus/FileMenu.scala
@@ -1,7 +1,7 @@
 package com.melvic.chi.views.menus
 
 import com.melvic.chi.config.Preferences
-import com.melvic.chi.views.PreferencesDialog
+import com.melvic.chi.views.dialogs.PreferencesDialog
 
 import java.awt.Frame
 import java.awt.event.{ActionEvent, KeyEvent}
diff --git a/src/main/scala/com/melvic/chi/views/menus/MenuBar.scala b/src/main/scala/com/melvic/chi/views/menus/MenuBar.scala
index 2a40177..299d21e 100644
--- a/src/main/scala/com/melvic/chi/views/menus/MenuBar.scala
+++ b/src/main/scala/com/melvic/chi/views/menus/MenuBar.scala
@@ -1,7 +1,8 @@
 package com.melvic.chi.views.menus
 
 import com.melvic.chi.config.Preferences
-import com.melvic.chi.views.{EditorComponent, PreferencesDialog}
+import com.melvic.chi.views.EditorComponent
+import com.melvic.chi.views.dialogs.PreferencesDialog
 
 import java.awt.Frame
 import javax.swing.JMenuBar