diff --git a/Userland/Libraries/LibGUI/GlyphMapWidget.cpp b/Userland/Libraries/LibGUI/GlyphMapWidget.cpp
index 2c657e9979..d0ca319507 100644
--- a/Userland/Libraries/LibGUI/GlyphMapWidget.cpp
+++ b/Userland/Libraries/LibGUI/GlyphMapWidget.cpp
@@ -113,6 +113,7 @@ Gfx::IntRect GlyphMapWidget::get_outer_rect(int glyph) const
 
 void GlyphMapWidget::update_glyph(int glyph)
 {
+    set_glyph_modified(glyph, true);
     update(get_outer_rect(glyph));
 }
 
@@ -146,13 +147,38 @@ void GlyphMapWidget::paint_event(PaintEvent& event)
             else if (auto* emoji = Gfx::Emoji::emoji_for_code_point(glyph))
                 painter.draw_emoji(inner_rect.location(), *emoji, font());
         } else if (font().contains_glyph(glyph)) {
-            painter.fill_rect(outer_rect, palette().base());
+            if (m_highlight_modifications && m_modified_glyphs.contains(glyph)) {
+                if (m_original_font->contains_glyph(glyph)) {
+                    // Modified
+                    if (palette().is_dark())
+                        painter.fill_rect(outer_rect, Gfx::Color { 0, 65, 159 });
+                    else
+                        painter.fill_rect(outer_rect, Gfx::Color { 138, 185, 252 });
+                } else {
+                    // Newly created
+                    if (palette().is_dark())
+                        painter.fill_rect(outer_rect, Gfx::Color { 8, 127, 0 });
+                    else
+                        painter.fill_rect(outer_rect, Gfx::Color { 133, 251, 116 });
+                }
+            } else {
+                painter.fill_rect(outer_rect, palette().base());
+            }
             painter.draw_glyph(inner_rect.location(), glyph, palette().base_text());
         } else if (auto* emoji = Gfx::Emoji::emoji_for_code_point(glyph)) {
             painter.fill_rect(outer_rect, Gfx::Color { 255, 150, 150 });
             painter.draw_emoji(inner_rect.location(), *emoji, font());
-        } else
-            painter.fill_rect(outer_rect, palette().window());
+        } else {
+            if (m_highlight_modifications && m_original_font->contains_glyph(glyph)) {
+                // Deleted
+                if (palette().is_dark())
+                    painter.fill_rect(outer_rect, Gfx::Color { 127, 0, 0 });
+                else
+                    painter.fill_rect(outer_rect, Gfx::Color { 255, 150, 150 });
+            } else {
+                painter.fill_rect(outer_rect, palette().window());
+            }
+        }
     }
     painter.draw_focus_rect(get_outer_rect(m_active_glyph), palette().focus_outline());
 }
@@ -401,4 +427,33 @@ void GlyphMapWidget::set_active_range(Unicode::CodePointRange range)
     update();
 }
 
+void GlyphMapWidget::set_highlight_modifications(bool highlight_modifications)
+{
+    if (m_highlight_modifications == highlight_modifications)
+        return;
+
+    m_highlight_modifications = highlight_modifications;
+    update();
+}
+
+void GlyphMapWidget::set_glyph_modified(u32 glyph, bool modified)
+{
+    if (modified)
+        m_modified_glyphs.set(glyph);
+    else
+        m_modified_glyphs.remove(glyph);
+}
+
+bool GlyphMapWidget::glyph_is_modified(u32 glyph)
+{
+    return m_modified_glyphs.contains(glyph);
+}
+
+void GlyphMapWidget::set_font(Gfx::Font const& font)
+{
+    AbstractScrollableWidget::set_font(font);
+    m_original_font = font.clone();
+    m_modified_glyphs.clear();
+}
+
 }
diff --git a/Userland/Libraries/LibGUI/GlyphMapWidget.h b/Userland/Libraries/LibGUI/GlyphMapWidget.h
index 31f8b71da3..82634f5733 100644
--- a/Userland/Libraries/LibGUI/GlyphMapWidget.h
+++ b/Userland/Libraries/LibGUI/GlyphMapWidget.h
@@ -21,6 +21,8 @@ class GlyphMapWidget final : public AbstractScrollableWidget {
 public:
     virtual ~GlyphMapWidget() override = default;
 
+    void set_font(Gfx::Font const&);
+
     class Selection {
     public:
         Selection() = default;
@@ -60,6 +62,10 @@ public:
     void scroll_to_glyph(int);
     void update_glyph(int);
 
+    void set_highlight_modifications(bool);
+    void set_glyph_modified(u32 glyph, bool modified);
+    bool glyph_is_modified(u32 glyph);
+
     void select_previous_existing_glyph();
     void select_next_existing_glyph();
 
@@ -88,6 +94,7 @@ private:
 
     void recalculate_content_size();
 
+    RefPtr<Gfx::Font> m_original_font;
     int m_glyph_count { 0x110000 };
     int m_columns { 0 };
     int m_rows { 0 };
@@ -97,6 +104,8 @@ private:
     int m_active_glyph { 0 };
     int m_visible_glyphs { 0 };
     bool m_in_drag_select { false };
+    bool m_highlight_modifications { false };
+    HashTable<u32> m_modified_glyphs;
     Unicode::CodePointRange m_active_range { 0x0000, 0x10FFFF };
     RefPtr<Core::Timer> m_automatic_selection_scroll_timer;
     Gfx::IntPoint m_last_mousemove_position;