diff --git a/appview/pages/templates/repo/commit.html b/appview/pages/templates/repo/commit.html
--- a/appview/pages/templates/repo/commit.html
+++ b/appview/pages/templates/repo/commit.html
@@ -123,7 +123,10 @@ {{ template "repo/fragments/diff" (list .RepoInfo.FullName .Diff .DiffOpts) }}
 {{end}}
 
 {{ define "contentAfterLeft" }}
-  <div class="sticky top-0">
+  <div class="flex flex-col gap-4 col-span-1 md:col-span-2 mt-4">
+    {{ template "repo/fragments/diffOpts" .DiffOpts }}
+  </div>
+  <div class="sticky top-0 mt-4">
     {{ template "repo/fragments/diffChangedFiles" .Diff }}
   </div>
 {{end}}
diff --git a/appview/pages/templates/repo/compare/compare.html b/appview/pages/templates/repo/compare/compare.html
--- a/appview/pages/templates/repo/compare/compare.html
+++ b/appview/pages/templates/repo/compare/compare.html
@@ -54,7 +54,10 @@ {{ template "repo/fragments/diff" (list .RepoInfo.FullName .Diff .DiffOpts) }}
 {{end}}
 
 {{ define "contentAfterLeft" }}
-  <div class="sticky top-0">
-  {{ template "repo/fragments/diffChangedFiles" .Diff }}
+  <div class="flex flex-col gap-4 col-span-1 md:col-span-2 mt-4">
+    {{ template "repo/fragments/diffOpts" .DiffOpts }}
+  </div>
+  <div class="sticky top-0 mt-4">
+    {{ template "repo/fragments/diffChangedFiles" .Diff }}
   </div>
 {{end}}
diff --git a/appview/pages/templates/repo/fragments/diffChangedFiles.html b/appview/pages/templates/repo/fragments/diffChangedFiles.html
--- a/appview/pages/templates/repo/fragments/diffChangedFiles.html
+++ b/appview/pages/templates/repo/fragments/diffChangedFiles.html
@@ -1,15 +1,13 @@
 {{ define "repo/fragments/diffChangedFiles" }}
   {{ $stat := .Stat }}
   {{ $fileTree := fileTree .ChangedFiles }}
-  <div class="col-span-1 md:col-span-2 mt-4">
-    <section class="sticky top-0 overflow-x-auto text-sm px-6 py-2 border border-gray-200 dark:border-gray-700 w-full mx-auto md:min-h-screen rounded bg-white dark:bg-gray-800 drop-shadow-sm">
-      <div class="diff-stat">
-        <div class="flex gap-2 items-center">
-          <strong class="text-sm uppercase dark:text-gray-200">Changed files</strong>
-          {{ template "repo/fragments/diffStatPill" $stat }}
-        </div>
-        {{ template "repo/fragments/fileTree" $fileTree }}
+  <section class="overflow-x-auto text-sm px-6 py-2 border border-gray-200 dark:border-gray-700 w-full mx-auto md:min-h-screen rounded bg-white dark:bg-gray-800 drop-shadow-sm">
+    <div class="diff-stat">
+      <div class="flex gap-2 items-center">
+        <strong class="text-sm uppercase dark:text-gray-200">Changed files</strong>
+        {{ template "repo/fragments/diffStatPill" $stat }}
       </div>
-    </section>
-  </div>
+      {{ template "repo/fragments/fileTree" $fileTree }}
+    </div>
+  </section>
 {{ end }}
diff --git a/appview/pages/templates/repo/fragments/diffOpts.html b/appview/pages/templates/repo/fragments/diffOpts.html
new file mode 100644
--- /dev/null
+++ b/appview/pages/templates/repo/fragments/diffOpts.html
@@ -0,0 +1,28 @@
+{{ define "repo/fragments/diffOpts" }}
+  <section class="flex flex-col gap-2 overflow-x-auto text-sm px-6 py-2 border border-gray-200 dark:border-gray-700 w-full mx-auto rounded bg-white dark:bg-gray-800 drop-shadow-sm">
+    <strong class="text-sm uppercase dark:text-gray-200">options</strong>
+    {{ $active := "unified" }}
+    {{ if .Split }}
+      {{ $active = "split" }}
+    {{ end }}
+    {{ $values := list "unified" "split" }}
+    {{ block "tabSelector" (dict "Name" "diff" "Values" $values "Active" $active) }} {{ end }}
+  </section>
+{{ end }}
+
+{{ define "tabSelector" }}
+  {{ $name := .Name }}
+  {{ $all := .Values }}
+  {{ $active := .Active }}
+  <div class="flex justify-between divide-x divide-gray-200 dark:divide-gray-700 rounded border border-gray-200 dark:border-gray-700 overflow-hidden">
+    {{ $activeTab := "bg-white dark:bg-gray-700 shadow-sm" }}
+    {{ $inactiveTab := "bg-gray-100 dark:bg-gray-800 shadow-inner" }}
+    {{ range $index, $value := $all }}
+      {{ $isActive := eq $value $active }}
+      <a href="?{{ $name }}={{ $value }}"
+         class="py-2 text-sm w-full block hover:no-underline text-center {{ if $isActive }} {{$activeTab }} {{ else }} {{ $inactiveTab }} {{ end }}">
+       {{ $value }}
+      </a>
+    {{ end }}
+  </div>
+{{ end }}
diff --git a/appview/pages/templates/repo/pulls/interdiff.html b/appview/pages/templates/repo/pulls/interdiff.html
--- a/appview/pages/templates/repo/pulls/interdiff.html
+++ b/appview/pages/templates/repo/pulls/interdiff.html
@@ -72,7 +72,10 @@ {{ template "repo/fragments/interdiff" (list .RepoInfo.FullName .Interdiff .DiffOpts) }}
 {{end}}
 
 {{ define "contentAfterLeft" }}
-  <div class="sticky top-0">
+  <div class="flex flex-col gap-4 col-span-1 md:col-span-2 mt-4">
+    {{ template "repo/fragments/diffOpts" .DiffOpts }}
+  </div>
+  <div class="sticky top-0 mt-4">
     {{ template "repo/fragments/interdiffFiles" .Interdiff }}
   </div>
 {{end}}
diff --git a/appview/pages/templates/repo/pulls/patch.html b/appview/pages/templates/repo/pulls/patch.html
--- a/appview/pages/templates/repo/pulls/patch.html
+++ b/appview/pages/templates/repo/pulls/patch.html
@@ -78,7 +78,10 @@ {{ template "repo/fragments/diff" (list .RepoInfo.FullName .Diff .DiffOpts) }}
 {{end}}
 
 {{ define "contentAfterLeft" }}
-  <div class="sticky top-0">
+  <div class="flex flex-col gap-4 col-span-1 md:col-span-2 mt-4">
+    {{ template "repo/fragments/diffOpts" .DiffOpts }}
+  </div>
+  <div class="sticky top-0 mt-4">
     {{ template "repo/fragments/diffChangedFiles" .Diff }}
   </div>
 {{end}}
diff --git a/types/split.go b/types/split.go
--- a/types/split.go
+++ b/types/split.go
@@ -36,7 +36,7 @@ func SeparateLines(fragment *gitdiff.TextFragment) ([]SplitLine, []SplitLine) {
 	lines := fragment.Lines
 	var leftLines, rightLines []SplitLine
 	oldLineNum := fragment.OldPosition
-	newLineNum := fragment.OldPosition
+	newLineNum := fragment.NewPosition
 
 	// process deletions and additions in groups for better alignment
 	i := 0