diff --git a/src/Commands/Diff.cs b/src/Commands/Diff.cs
index e92b2234..aaa6e125 100644
--- a/src/Commands/Diff.cs
+++ b/src/Commands/Diff.cs
@@ -12,11 +12,11 @@ namespace SourceGit.Commands
         private const string PREFIX_LFS_DEL = "-version https://git-lfs.github.com/spec/";
         private const string PREFIX_LFS_MODIFY = " version https://git-lfs.github.com/spec/";
 
-        public Diff(string repo, Models.DiffOption opt)
+        public Diff(string repo, Models.DiffOption opt, int unified)
         {
             WorkingDirectory = repo;
             Context = repo;
-            Args = $"diff --ignore-cr-at-eol --unified=4 {opt}";
+            Args = $"diff --ignore-cr-at-eol --unified={unified} {opt}";
         }
 
         public Models.DiffResult Result()
diff --git a/src/Converters/IntConverters.cs b/src/Converters/IntConverters.cs
index 820f62c5..8235a3ef 100644
--- a/src/Converters/IntConverters.cs
+++ b/src/Converters/IntConverters.cs
@@ -7,6 +7,9 @@ namespace SourceGit.Converters
         public static readonly FuncValueConverter<int, bool> IsGreaterThanZero =
             new FuncValueConverter<int, bool>(v => v > 0);
 
+        public static readonly FuncValueConverter<int, bool> IsGreaterThanFour =
+            new FuncValueConverter<int, bool>(v => v > 4);
+
         public static readonly FuncValueConverter<int, bool> IsZero =
             new FuncValueConverter<int, bool>(v => v == 0);
 
diff --git a/src/Resources/Icons.axaml b/src/Resources/Icons.axaml
index f33f0073..b61e6839 100644
--- a/src/Resources/Icons.axaml
+++ b/src/Resources/Icons.axaml
@@ -95,4 +95,6 @@
   <StreamGeometry x:Key="Icons.GitFlow.Feature">M939 94v710L512 998 85 805V94h-64A21 21 0 010 73v-0C0 61 10 51 21 51h981c12 0 21 10 21 21v0c0 12-10 21-21 21h-64zm-536 588L512 624l109 58c6 3 13 4 20 3a32 32 0 0026-37l-21-122 88-87c5-5 8-11 9-18a32 32 0 00-27-37l-122-18-54-111a32 32 0 00-57 0l-54 111-122 18c-7 1-13 4-18 9a33 33 0 001 46l88 87-21 122c-1 7-0 14 3 20a32 32 0 0043 14z</StreamGeometry>
   <StreamGeometry x:Key="Icons.GitFlow.Hotfix">M236 542a32 32 0 109 63l86-12a180 180 0 0022 78l-71 47a32 32 0 1035 53l75-50a176 176 0 00166 40L326 529zM512 16C238 16 16 238 16 512s222 496 496 496 496-222 496-496S786 16 512 16zm0 896c-221 0-400-179-400-400a398 398 0 0186-247l561 561A398 398 0 01512 912zm314-154L690 622a179 179 0 004-29l85 12a32 32 0 109-63l-94-13v-49l94-13a32 32 0 10-9-63l-87 12a180 180 0 00-20-62l71-47A32 32 0 10708 252l-75 50a181 181 0 00-252 10l-115-115A398 398 0 01512 112c221 0 400 179 400 400a398 398 0 01-86 247z</StreamGeometry>
   <StreamGeometry x:Key="Icons.GitFlow.Release">M884 159l-18-18a43 43 0 00-38-12l-235 43a166 166 0 00-101 60L400 349a128 128 0 00-148 47l-120 171a21 21 0 005 29l17 12a128 128 0 00178-32l27-38 124 124-38 27a128 128 0 00-32 178l12 17a21 21 0 0029 5l171-120a128 128 0 0047-148l117-92A166 166 0 00853 431l43-235a43 43 0 00-12-38zm-177 249a64 64 0 110-90 64 64 0 010 90zm-373 312a21 21 0 010 30l-139 139a21 21 0 01-30 0l-30-30a21 21 0 010-30l139-139a21 21 0 0130 0z</StreamGeometry>
+  <StreamGeometry x:Key="Icons.Lines.Incr">M408 232C408 210 426 192 448 192h416a40 40 0 110 80H448a40 40 0 01-40-40zM408 512c0-22 18-40 40-40h416a40 40 0 110 80H448A40 40 0 01408 512zM448 752A40 40 0 00448 832h416a40 40 0 100-80H448zM32 480l132 0 0-128 64 0 0 128 132 0 0 64-132 0 0 128-64 0 0-128-132 0Z</StreamGeometry>
+  <StreamGeometry x:Key="Icons.Lines.Decr">M408 232C408 210 426 192 448 192h416a40 40 0 110 80H448a40 40 0 01-40-40zM408 512c0-22 18-40 40-40h416a40 40 0 110 80H448A40 40 0 01408 512zM448 752A40 40 0 00448 832h416a40 40 0 100-80H448zM32 480l328 0 0 64-328 0Z</StreamGeometry>
 </ResourceDictionary>
diff --git a/src/Resources/Locales/en_US.axaml b/src/Resources/Locales/en_US.axaml
index 08864bd1..685cb1be 100644
--- a/src/Resources/Locales/en_US.axaml
+++ b/src/Resources/Locales/en_US.axaml
@@ -159,6 +159,8 @@
   <x:String x:Key="Text.Diff.SideBySide" xml:space="preserve">Side-By-Side Diff</x:String>
   <x:String x:Key="Text.Diff.SyntaxHighlight" xml:space="preserve">Syntax Highlighting</x:String>
   <x:String x:Key="Text.Diff.UseMerger" xml:space="preserve">Open In Merge Tool</x:String>
+  <x:String x:Key="Text.Diff.VisualLines.Decr" xml:space="preserve">Decrease Number of Visible Lines</x:String>
+  <x:String x:Key="Text.Diff.VisualLines.Incr" xml:space="preserve">Increase Number of Visible Lines</x:String>
   <x:String x:Key="Text.Diff.Welcome" xml:space="preserve">SELECT FILE TO VIEW CHANGES</x:String>
   <x:String x:Key="Text.DiffWithMerger" xml:space="preserve">Open In Merge Tool</x:String>
   <x:String x:Key="Text.Discard" xml:space="preserve">Discard Changes</x:String>
diff --git a/src/Resources/Locales/zh_CN.axaml b/src/Resources/Locales/zh_CN.axaml
index 2f79f29e..ac48aec9 100644
--- a/src/Resources/Locales/zh_CN.axaml
+++ b/src/Resources/Locales/zh_CN.axaml
@@ -159,6 +159,8 @@
   <x:String x:Key="Text.Diff.SideBySide" xml:space="preserve">分列对比</x:String>
   <x:String x:Key="Text.Diff.SyntaxHighlight" xml:space="preserve">语法高亮</x:String>
   <x:String x:Key="Text.Diff.UseMerger" xml:space="preserve">使用外部合并工具查看</x:String>
+  <x:String x:Key="Text.Diff.VisualLines.Decr" xml:space="preserve">减少可见的行数</x:String>
+  <x:String x:Key="Text.Diff.VisualLines.Incr" xml:space="preserve">增加可见的行数</x:String>
   <x:String x:Key="Text.Diff.Welcome" xml:space="preserve">请选择需要对比的文件</x:String>
   <x:String x:Key="Text.DiffWithMerger" xml:space="preserve">使用外部比对工具查看</x:String>
   <x:String x:Key="Text.Discard" xml:space="preserve">放弃更改确认</x:String>
diff --git a/src/Resources/Styles.axaml b/src/Resources/Styles.axaml
index ec4e0221..376f9424 100644
--- a/src/Resources/Styles.axaml
+++ b/src/Resources/Styles.axaml
@@ -245,6 +245,9 @@
   <Style Selector="Button.icon_button:pointerover /template/ ContentPresenter#PART_ContentPresenter, RepeatButton.icon_button:pointerover /template/ ContentPresenter#PART_ContentPresenter">
     <Setter Property="Opacity" Value="1"/>
   </Style>
+  <Style Selector="Button.icon_button:disabled Path">
+    <Setter Property="Fill" Value="{DynamicResource Brush.FG2}"/>
+  </Style>
 
   <Style Selector="Button.flat">
     <Setter Property="BorderThickness" Value="0"/>
diff --git a/src/ViewModels/DiffContext.cs b/src/ViewModels/DiffContext.cs
index 3400b5ea..3aad22ea 100644
--- a/src/ViewModels/DiffContext.cs
+++ b/src/ViewModels/DiffContext.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Threading.Tasks;
 
@@ -63,6 +64,16 @@ namespace SourceGit.ViewModels
             set => SetProperty(ref _syncScrollOffset, value);
         }
 
+        public int Unified
+        {
+            get => _unified;
+            set
+            {
+                if (SetProperty(ref _unified, value))
+                    LoadDiffContent();
+            }
+        }
+
         public DiffContext(string repo, Models.DiffOption option, DiffContext previous = null)
         {
             _repo = repo;
@@ -74,9 +85,40 @@ namespace SourceGit.ViewModels
                 _content = previous._content;
             }
 
+            LoadDiffContent();
+        }
+
+        public void IncrUnified()
+        {
+            Unified = _unified + 1;
+        }
+
+        public void DecrUnified()
+        {
+            Unified = Math.Max(4, _unified - 1);
+        }
+
+        public void OpenExternalMergeTool()
+        {
+            var type = Preference.Instance.ExternalMergeToolType;
+            var exec = Preference.Instance.ExternalMergeToolPath;
+
+            var tool = Models.ExternalMerger.Supported.Find(x => x.Type == type);
+            if (tool == null || !File.Exists(exec))
+            {
+                App.RaiseException(_repo, "Invalid merge tool in preference setting!");
+                return;
+            }
+
+            var args = tool.Type != 0 ? tool.DiffCmd : Preference.Instance.ExternalMergeToolDiffCmd;
+            Task.Run(() => Commands.MergeTool.OpenForDiff(_repo, exec, args, _option));
+        }
+
+        private void LoadDiffContent()
+        {
             Task.Run(() =>
             {
-                var latest = new Commands.Diff(repo, option).Result();
+                var latest = new Commands.Diff(_repo, _option, _unified).Result();
                 var rs = null as object;
 
                 if (latest.TextDiff != null)
@@ -92,15 +134,15 @@ namespace SourceGit.ViewModels
                     if (IMG_EXTS.Contains(ext))
                     {
                         var imgDiff = new Models.ImageDiff();
-                        if (option.Revisions.Count == 2)
+                        if (_option.Revisions.Count == 2)
                         {
-                            imgDiff.Old = BitmapFromRevisionFile(repo, option.Revisions[0], oldPath);
-                            imgDiff.New = BitmapFromRevisionFile(repo, option.Revisions[1], oldPath);
+                            imgDiff.Old = BitmapFromRevisionFile(_repo, _option.Revisions[0], oldPath);
+                            imgDiff.New = BitmapFromRevisionFile(_repo, _option.Revisions[1], oldPath);
                         }
                         else
                         {
-                            var fullPath = Path.Combine(repo, _option.Path);
-                            imgDiff.Old = BitmapFromRevisionFile(repo, "HEAD", oldPath);
+                            var fullPath = Path.Combine(_repo, _option.Path);
+                            imgDiff.Old = BitmapFromRevisionFile(_repo, "HEAD", oldPath);
                             imgDiff.New = File.Exists(fullPath) ? new Bitmap(fullPath) : null;
                         }
                         rs = imgDiff;
@@ -108,15 +150,15 @@ namespace SourceGit.ViewModels
                     else
                     {
                         var binaryDiff = new Models.BinaryDiff();
-                        if (option.Revisions.Count == 2)
+                        if (_option.Revisions.Count == 2)
                         {
-                            binaryDiff.OldSize = new Commands.QueryFileSize(repo, oldPath, option.Revisions[0]).Result();
-                            binaryDiff.NewSize = new Commands.QueryFileSize(repo, _option.Path, option.Revisions[1]).Result();
+                            binaryDiff.OldSize = new Commands.QueryFileSize(_repo, oldPath, _option.Revisions[0]).Result();
+                            binaryDiff.NewSize = new Commands.QueryFileSize(_repo, _option.Path, _option.Revisions[1]).Result();
                         }
                         else
                         {
-                            var fullPath = Path.Combine(repo, _option.Path);
-                            binaryDiff.OldSize = new Commands.QueryFileSize(repo, oldPath, "HEAD").Result();
+                            var fullPath = Path.Combine(_repo, _option.Path);
+                            binaryDiff.OldSize = new Commands.QueryFileSize(_repo, oldPath, "HEAD").Result();
                             binaryDiff.NewSize = File.Exists(fullPath) ? new FileInfo(fullPath).Length : 0;
                         }
                         rs = binaryDiff;
@@ -146,22 +188,6 @@ namespace SourceGit.ViewModels
             });
         }
 
-        public void OpenExternalMergeTool()
-        {
-            var type = Preference.Instance.ExternalMergeToolType;
-            var exec = Preference.Instance.ExternalMergeToolPath;
-
-            var tool = Models.ExternalMerger.Supported.Find(x => x.Type == type);
-            if (tool == null || !File.Exists(exec))
-            {
-                App.RaiseException(_repo, "Invalid merge tool in preference setting!");
-                return;
-            }
-
-            var args = tool.Type != 0 ? tool.DiffCmd : Preference.Instance.ExternalMergeToolDiffCmd;
-            Task.Run(() => Commands.MergeTool.OpenForDiff(_repo, exec, args, _option));
-        }
-
         private Bitmap BitmapFromRevisionFile(string repo, string revision, string file)
         {
             var stream = Commands.QueryFileContent.Run(repo, revision, file);
@@ -181,5 +207,6 @@ namespace SourceGit.ViewModels
         private bool _isTextDiff = false;
         private object _content = null;
         private Vector _syncScrollOffset = Vector.Zero;
+        private int _unified = 4;
     }
 }
diff --git a/src/Views/DiffView.axaml b/src/Views/DiffView.axaml
index 5ba5a211..6fa344fd 100644
--- a/src/Views/DiffView.axaml
+++ b/src/Views/DiffView.axaml
@@ -34,6 +34,14 @@
 
           <!-- Toolbar Buttons -->
           <StackPanel Grid.Column="3" Margin="8,0,0,0" Orientation="Horizontal" VerticalAlignment="Center">
+            <Button Classes="icon_button" Width="32" Command="{Binding IncrUnified}" IsVisible="{Binding IsTextDiff}" ToolTip.Tip="{DynamicResource Text.Diff.VisualLines.Incr}">
+              <Path Width="12" Height="12" Stretch="Uniform" Margin="0,6,0,0" Data="{StaticResource Icons.Lines.Incr}"/>
+            </Button>
+
+            <Button Classes="icon_button" Width="32" Command="{Binding DecrUnified}" IsVisible="{Binding IsTextDiff}" ToolTip.Tip="{DynamicResource Text.Diff.VisualLines.Decr}" IsEnabled="{Binding Unified, Converter={x:Static c:IntConverters.IsGreaterThanFour}}">
+              <Path Width="12" Height="12" Stretch="Uniform" Margin="0,6,0,0" Data="{StaticResource Icons.Lines.Decr}"/>
+            </Button>
+            
             <ToggleButton Classes="line_path"
                           Width="32" Height="18"
                           Background="Transparent"