diff --git a/README.md b/README.md
index 496ddbe..5568650 100644
--- a/README.md
+++ b/README.md
@@ -92,6 +92,14 @@ ignoreErrors in scalafmt := false              // current project
 ignoreErrors in (Compile, scalafmt) := false   // current project, specific configuration
 ```
 
+By default, scalafmt just lists the files that have differences. You can configure it to show the actual diff like this:
+
+```scala
+scalafmtShowDiff in (ThisBuild, scalafmt) := false // all projects
+scalafmtShowDiff in scalafmt := false              // current project
+scalafmtShowDiff in (Compile, scalafmt) := false   // current project, specific configuration
+```
+
 ## Additional configuration
 
 The scalafmt task is defined by default for the compile and test configurations. To define it for additional
diff --git a/sbt-scalafmt/build.sbt b/sbt-scalafmt/build.sbt
index 0be5ada..f9fbb3f 100644
--- a/sbt-scalafmt/build.sbt
+++ b/sbt-scalafmt/build.sbt
@@ -6,7 +6,8 @@ buildInfoPackage := "com.lucidchart.sbt.scalafmt"
 
 libraryDependencies ++= Seq(
   "com.google.code.findbugs" % "jsr305" % "3.0.2" % Provided, // fixes warnings about javax annotations
-  "com.google.guava" % "guava" % "19.0"
+  "com.google.guava" % "guava" % "19.0",
+  "com.michaelpollmeier" %% "colordiff" % "0.8"
 )
 
 sbtPlugin := true
diff --git a/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtCorePlugin.scala b/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtCorePlugin.scala
index c2a7e28..be4206e 100644
--- a/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtCorePlugin.scala
+++ b/sbt-scalafmt/src/main/scala/com/lucidchart/sbt/scalafmt/ScalafmtCorePlugin.scala
@@ -1,5 +1,6 @@
 package com.lucidchart.sbt.scalafmt
 
+import colordiff.ColorDiff
 import com.google.common.cache._
 import com.lucidchart.scalafmt.api.{Dialect, ScalafmtFactory, Scalafmtter}
 import java.io.FileNotFoundException
@@ -9,6 +10,7 @@ import sbt.Keys._
 import sbt._
 import sbt.plugins.{IvyPlugin, JvmPlugin}
 import scala.collection.breakOut
+import scala.io.Source
 import scala.util.control.NonFatal
 import scala.util.control.Exception.catching
 
@@ -45,6 +47,11 @@ object ScalafmtCorePlugin extends AutoPlugin {
       "Fail build when one or more style issues are found",
       CSetting
     )
+    val scalafmtShowDiff = SettingKey[Boolean](
+      "scalafmt-show-diff",
+      "show differences between original and formatted version",
+      CSetting
+    )
 
     private[this] val scalafmtFn = Def.task {
       val ignoreErrors = this.ignoreErrors.value
@@ -167,15 +174,21 @@ object ScalafmtCorePlugin extends AutoPlugin {
 
             val scalafmtter = scalafmtFn.value
             val failForStyleIssues = scalafmtFailTest.value
-            val differentCount = sources.value.count { file =>
-              val content = IO.read(file)
-              val hasChanges = content != scalafmtter(file.toString, content)
-              if (hasChanges) {
-                val msg = s"$file has changes after scalafmt"
-                if (failForStyleIssues) logger.error(msg)
-                else logger.warn(msg)
-              }
-              hasChanges
+            val showDiff = scalafmtShowDiff.value
+            val differentCount = sources.value.count {
+              file =>
+                val original = IO.read(file)
+                val formatted = scalafmtter(file.toString, original)
+                val hasChanges = original != formatted
+                if (hasChanges) {
+                  val msg = if (showDiff) {
+                    val diff = ColorDiff(original.split('\n').toList, formatted.split('\n').toList)
+                    s"$file has changes after scalafmt:\n$diff"
+                  } else s"$file has changes after scalafmt"
+                  if (failForStyleIssues) logger.error(msg)
+                  else logger.warn(msg)
+                }
+                hasChanges
             }
             AnalysisPlatform.counted("Scala source", "", "s", differentCount).foreach { message =>
               val msg = s"$message not formatted in $display"
@@ -227,7 +240,8 @@ object ScalafmtCorePlugin extends AutoPlugin {
     scalafmtOnCompile := false,
     scalafmtTestOnCompile := false,
     scalafmtVersion := "0.6.8",
-    scalafmtFailTest := true
+    scalafmtFailTest := true,
+    scalafmtShowDiff := false
   )
 
   override val projectSettings = Seq(