diff --git a/makefile b/makefile
index 990b016..6fbb83c 100644
--- a/makefile
+++ b/makefile
@@ -6,14 +6,19 @@ OPTIMIZED_MORE=-Ofast -march=native -funit-at-a-time -flto # binary will not be
 DEBUG= # -g
 STD=-std=c99 # maybe consider moving to c11 and using safer string handling
 
-# Dependencies
-DEPS='webkit2gtk-4.1'
-# DEPS='webkitgtk-6.0'
-INCS=`pkg-config --cflags ${DEPS}`
-LIBS=`pkg-config --libs ${DEPS}`
+# Dependencies for WebkitGTK4/GTK3
+SRC_3=rosenrot3.c
+DEPS_3='webkit2gtk-4.1'
+INCS_3=`pkg-config --cflags ${DEPS_3}`
+LIBS_3=`pkg-config --libs ${DEPS_3}`
 
-# Code
-SRC=rosenrot.c
+# Dependencies for WebkitGTK6/GTK4
+SRC_4=rosenrot4.c
+DEPS_4='webkitgtk-6.0'
+INCS_4=`pkg-config --cflags ${DEPS_4}`
+LIBS_4=`pkg-config --libs ${DEPS_4}`
+
+# User config
 CONFIG=config.h
 
 # Plugins
@@ -34,10 +39,14 @@ RUNTIME_FILES_DIR=/opt/rosenrot/
 # Start 3 to 4 transition 
 # https://docs.gtk.org/gtk4/migrating-3to4.html
 # https://github.com/WebKit/WebKit/blob/ed1422596dce5ff012e64a38faf402ac1674fc7e/Source/WebKit/gtk/migrating-to-webkitgtk-6.0.md
-# DEPRECATION_FLAGS=-DGDK_DISABLE_DEPRECATED -DGTK_DISABLE_DEPRECATED
+DEPRECATION_FLAGS=-DGDK_DISABLE_DEPRECATED -DGTK_DISABLE_DEPRECATED
 
-build: $(SRC) $(PLUGINS) $(CONFIG) constants user_cache
-	$(CC) $(STD) $(WARNINGS) $(DEPRECATION_FLAGS) $(OPTIMIZED_MORE) $(DEBUG) $(INCS) $(PLUGINS) $(SRC) -o rosenrot $(LIBS) $(ADBLOCK)
+build: $(SRC_3) $(PLUGINS) $(CONFIG) constants user_cache
+	$(CC) $(STD) $(WARNINGS) $(OPTIMIZED_MORE) $(DEBUG) $(INCS_3) $(PLUGINS) $(SRC_3) -o rosenrot $(LIBS_3) $(ADBLOCK)
+	@echo
+
+build4: $(SRC_4) $(PLUGINS) $(CONFIG) constants user_cache
+	$(CC) $(STD) $(WARNINGS) $(DEPRECATION_FLAGS) $(OPTIMIZED_MORE) $(DEBUG) $(INCS_4) $(PLUGINS) $(SRC_4) -o rosenrot $(LIBS_4) $(ADBLOCK)
 	@echo
 
 constants:
diff --git a/rosenrot.c b/rosenrot3.c
similarity index 98%
rename from rosenrot.c
rename to rosenrot3.c
index da15cdb..b499768 100644
--- a/rosenrot.c
+++ b/rosenrot3.c
@@ -3,11 +3,7 @@
 #include <string.h>
 
 #include "config.h"
-#if GTK_NUM == 3
-    #include <webkit2/webkit2.h>
-#elif GTK_NUM == 4
-    #include <webkit/webkit.h>
-#endif
+#include <webkit2/webkit2.h>
 #include "plugins/plugins.h"
 
 /* Global declarations */
@@ -408,11 +404,8 @@ int main(int argc, char** argv)
     gtk_window_set_default_size(window, WIDTH, HEIGHT);
     g_signal_connect(window, "key-press-event", G_CALLBACK(handle_signal_keypress), notebook);
     g_signal_connect(window, "destroy", G_CALLBACK(exit), notebook);
-    #if GTK_NUM == 3
-        gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(notebook)); /* deprecated in GTK */
-    #elif GTK_NUM == 4
-        gtk_window_set_child(GTK_CONTAINER(window), GTK_WIDGET(notebook))
-    #endif
+
+    gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(notebook)); /* deprecated in GTK */
 
     // Bar
     bar.line_text = GTK_ENTRY_BUFFER(gtk_entry_buffer_new("", 0));
diff --git a/rosenrot4.c b/rosenrot4.c
new file mode 100644
index 0000000..6c6864e
--- /dev/null
+++ b/rosenrot4.c
@@ -0,0 +1,457 @@
+#include <gdk/gdk.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "config.h"
+#include <webkit/webkit.h>
+#include "plugins/plugins.h"
+
+/* Global declarations */
+static GtkNotebook* notebook;
+static GtkWindow* window;
+typedef enum { _SEARCH, _FIND, _HIDDEN } Bar_entry_mode;
+static struct {
+    GtkHeaderBar* widget;
+    GtkEntry* line;
+    GtkEntryBuffer* line_text;
+    Bar_entry_mode entry_mode;
+} bar;
+static int num_tabs = 0;
+static int custom_style_enabled = 1;
+
+/* Forward declarations */
+void toggle_bar(GtkNotebook* notebook, Bar_entry_mode mode);
+void notebook_create_new_tab(GtkNotebook* notebook, const char* uri);
+
+/* Utils */
+WebKitWebView* notebook_get_webview(GtkNotebook* notebook)
+{
+    return WEBKIT_WEB_VIEW(gtk_notebook_get_nth_page(notebook, gtk_notebook_get_current_page(notebook)));
+}
+
+/* Load content*/
+void load_uri(WebKitWebView* view, const char* uri)
+{
+    if (strlen(uri) == 0) {
+        webkit_web_view_load_uri(view, "");
+        toggle_bar(notebook, _SEARCH);
+    } else if (g_str_has_prefix(uri, "http://") || g_str_has_prefix(uri, "https://") || g_str_has_prefix(uri, "file://") || g_str_has_prefix(uri, "about:")) {
+        webkit_web_view_load_uri(view, uri);
+    } else if (strstr(uri, ".com") || strstr(uri, ".org")) {
+        char tmp[strlen("https://") + strlen(uri) + 1];
+        snprintf(tmp, sizeof(tmp) + 1, "https://%s", uri);
+        webkit_web_view_load_uri(view, tmp);
+    } else {
+        // Check for shortcuts
+        int l = SHORTCUT_N + strlen(uri) + 1;
+        char uri_expanded[l];
+        str_init(uri_expanded, l);
+        int check = shortcut_expand(uri, uri_expanded);
+        if (check == 2) {
+            webkit_web_view_load_uri(view, uri_expanded);
+        } else {
+            // Feed into search engine.
+            char tmp[strlen(uri) + strlen(SEARCH)];
+            snprintf(tmp, sizeof(tmp), SEARCH, uri);
+            webkit_web_view_load_uri(view, tmp);
+        }
+    }
+}
+
+/* Deal with new load or changed load */
+void redirect_if_annoying(WebKitWebView* view, const char* uri)
+{
+    if (LIBRE_REDIRECT_ENABLED) {
+        int l = LIBRE_N + strlen(uri) + 1;
+        char uri_filtered[l];
+        str_init(uri_filtered, l);
+
+        int check = libre_redirect(uri, uri_filtered);
+        if (check == 2) webkit_web_view_load_uri(view, uri_filtered);
+    }
+}
+void set_custom_style(WebKitWebView* view)
+{
+    if (custom_style_enabled) {
+        char* style_js = malloc(STYLE_N + 1);
+        read_style_js(style_js);
+        webkit_web_view_evaluate_javascript(view, style_js, -1, NULL, "rosenrot-style-plugin", NULL, NULL, NULL);
+        free(style_js);
+    }
+}
+void handle_signal_load_changed(WebKitWebView* self, WebKitLoadEvent load_event,
+    GtkNotebook* notebook)
+{
+    switch (load_event) {
+        // https://webkitgtk.org/reference/webkit2gtk/2.5.1/WebKitWebView.html
+        case WEBKIT_LOAD_STARTED:
+        case WEBKIT_LOAD_COMMITTED:
+            set_custom_style(self);
+        case WEBKIT_LOAD_REDIRECTED:
+            redirect_if_annoying(self, webkit_web_view_get_uri(self));
+            break;
+        case WEBKIT_LOAD_FINISHED: {
+            set_custom_style(self);
+            /* Add gtk tab title */
+            const char* webpage_title = webkit_web_view_get_title(self);
+            const int max_length = 25;
+            char tab_title[max_length + 1];
+            if (webpage_title != NULL) {
+                for (int i = 0; i < (max_length); i++) {
+                    tab_title[i] = webpage_title[i];
+                    if (webpage_title[i] == '\0') {
+                        break;
+                    }
+                }
+                tab_title[max_length] = '\0';
+            }
+            gtk_notebook_set_tab_label_text(notebook, GTK_WIDGET(self),
+                webpage_title == NULL ? "—" : tab_title);
+        }
+    }
+}
+
+/* Create new tabs */
+GtkWidget* handle_signal_create_new_tab(WebKitWebView* self,
+    WebKitNavigationAction* navigation_action,
+    GtkNotebook* notebook)
+{
+    if (num_tabs < MAX_NUM_TABS || num_tabs == 0) {
+        WebKitURIRequest* uri_request = webkit_navigation_action_get_request(navigation_action);
+        const char* uri = webkit_uri_request_get_uri(uri_request);
+        printf("Creating new window: %s\n", uri);
+        notebook_create_new_tab(notebook, uri);
+        gtk_notebook_set_show_tabs(notebook, true);
+    } else {
+        webkit_web_view_evaluate_javascript(self, "alert('Too many tabs, not opening a new one')", -1, NULL, "rosenrot-alert-numtabs", NULL, NULL, NULL);
+    }
+    return NULL;
+    /*
+     WebKitGTK documentation recommends returning the new webview.
+     I imagine that this might allow e.g., to go back in a new tab
+     or generally to keep track of history.
+     However, this would require either modifying notebook_create_new_tab
+     or duplicating its contents, for unclear gain.
+   */
+}
+WebKitWebView* create_new_webview()
+{
+    char* style;
+    WebKitSettings* settings;
+    WebKitWebContext* web_context;
+    WebKitCookieManager* cookiemanager;
+    WebKitUserContentManager* contentmanager;
+
+    settings = webkit_settings_new_with_settings(WEBKIT_DEFAULT_SETTINGS, NULL);
+    if (CUSTOM_USER_AGENT) {
+        webkit_settings_set_user_agent(
+            settings,
+            "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, "
+            "like Gecko) Chrome/120.0.0.0 Safari/537.3");
+        // https://www.useragents.me
+    }
+    web_context = webkit_web_context_new_with_website_data_manager(webkit_website_data_manager_new(DATA_MANAGER_OPTS, NULL));
+    contentmanager = webkit_user_content_manager_new();
+    cookiemanager = webkit_web_context_get_cookie_manager(web_context);
+
+    webkit_cookie_manager_set_persistent_storage(cookiemanager, DATA_DIR "/cookies.sqlite", WEBKIT_COOKIE_PERSISTENT_STORAGE_SQLITE);
+
+    webkit_cookie_manager_set_accept_policy(cookiemanager, WEBKIT_COOKIE_POLICY_ACCEPT_ALWAYS);
+
+    if (g_file_get_contents("~/opt/rosenrot/style.css", &style, NULL, NULL)) {
+        webkit_user_content_manager_add_style_sheet(
+            contentmanager, webkit_user_style_sheet_new(style, WEBKIT_USER_CONTENT_INJECT_ALL_FRAMES, WEBKIT_USER_STYLE_LEVEL_USER, NULL, NULL));
+    }
+
+    return g_object_new(WEBKIT_TYPE_WEB_VIEW, "settings", settings, "web-context", web_context, "user-content-manager", contentmanager, NULL);
+}
+void notebook_create_new_tab(GtkNotebook* notebook, const char* uri)
+{
+    if (num_tabs < MAX_NUM_TABS || MAX_NUM_TABS == 0) {
+        WebKitWebView* view = create_new_webview();
+
+        g_signal_connect(view, "load_changed", G_CALLBACK(handle_signal_load_changed), notebook);
+        g_signal_connect(view, "create", G_CALLBACK(handle_signal_create_new_tab), notebook);
+
+        int n = gtk_notebook_append_page(notebook, GTK_WIDGET(view), NULL);
+        gtk_notebook_set_tab_reorderable(notebook, GTK_WIDGET(view), true);
+        gtk_widget_show_all(GTK_WIDGET(window));
+        gtk_widget_hide(GTK_WIDGET(bar.widget));
+        load_uri(view, (uri) ? uri : HOME);
+
+        set_custom_style(view);
+
+        gtk_notebook_set_current_page(notebook, n);
+        gtk_notebook_set_tab_label_text(notebook, GTK_WIDGET(view), "-");
+        webkit_web_view_set_zoom_level(view, ZOOM_START_LEVEL);
+        num_tabs += 1;
+    } else {
+        webkit_web_view_evaluate_javascript(notebook_get_webview(notebook), "alert('Too many tabs, not opening a new one')",
+            -1, NULL, "rosenrot-alert-numtabs", NULL, NULL, NULL);
+    }
+}
+
+/* Top bar */
+void toggle_bar(GtkNotebook* notebook, Bar_entry_mode mode)
+{
+    bar.entry_mode = mode;
+    switch (bar.entry_mode) {
+        case _SEARCH: {
+            const char* url = webkit_web_view_get_uri(notebook_get_webview(notebook));
+            gtk_entry_set_placeholder_text(bar.line, "Search");
+            gtk_entry_buffer_set_text(bar.line_text, url, strlen(url));
+            gtk_widget_show(GTK_WIDGET(bar.widget));
+            gtk_window_set_focus(window, GTK_WIDGET(bar.line));
+            break;
+        }
+        case _FIND: {
+            const char* search_text = webkit_find_controller_get_search_text(
+                webkit_web_view_get_find_controller(notebook_get_webview(notebook)));
+
+            if (search_text != NULL)
+                gtk_entry_buffer_set_text(bar.line_text, search_text, strlen(search_text));
+
+            gtk_entry_set_placeholder_text(bar.line, "Find");
+            gtk_widget_show(GTK_WIDGET(bar.widget));
+            gtk_window_set_focus(window, GTK_WIDGET(bar.line));
+            break;
+        }
+        case _HIDDEN:
+            gtk_widget_hide(GTK_WIDGET(bar.widget));
+    }
+}
+
+// Handle what happens when the user is on the bar and presses enter
+void handle_signal_bar_press_enter(GtkEntry* self, GtkNotebook* notebook)
+{
+    if (bar.entry_mode == _SEARCH)
+        load_uri(notebook_get_webview(notebook), gtk_entry_buffer_get_text(bar.line_text));
+    else if (bar.entry_mode == _FIND)
+        webkit_find_controller_search(
+            webkit_web_view_get_find_controller(notebook_get_webview(notebook)),
+            gtk_entry_buffer_get_text(bar.line_text),
+            WEBKIT_FIND_OPTIONS_CASE_INSENSITIVE | WEBKIT_FIND_OPTIONS_WRAP_AROUND,
+            G_MAXUINT);
+
+    gtk_widget_hide(GTK_WIDGET(bar.widget));
+}
+
+/* Handle shortcuts */
+// Act when a particular shortcut is detected
+int handle_shortcut(func id, GtkNotebook* notebook)
+{
+    static double zoom = ZOOM_START_LEVEL;
+    static bool is_fullscreen = 0;
+
+    WebKitWebView* view = notebook_get_webview(notebook);
+
+    switch (id) {
+        case goback:
+            webkit_web_view_go_back(view);
+            break;
+        case goforward:
+            webkit_web_view_go_forward(view);
+            break;
+
+        case toggle_custom_style: /* Ctrl s + Ctrl Shift R to reload */
+            if (custom_style_enabled)
+                custom_style_enabled = 0;
+            else
+                custom_style_enabled = 1;
+            // break; passthrough
+        case refresh:
+            webkit_web_view_reload(view);
+            break;
+        case refresh_force:
+            webkit_web_view_reload_bypass_cache(view);
+            break;
+
+        case back_to_home:
+            load_uri(view, HOME);
+            break;
+
+        case zoomin:
+            webkit_web_view_set_zoom_level(view,
+                (zoom += ZOOM_STEPSIZE));
+            break;
+        case zoomout:
+            webkit_web_view_set_zoom_level(view,
+                (zoom -= ZOOM_STEPSIZE));
+            break;
+        case zoom_reset:
+            webkit_web_view_set_zoom_level(view,
+                (zoom = ZOOM_START_LEVEL));
+            break;
+
+        case prev_tab:; // declarations aren't statements
+            // https://stackoverflow.com/questions/92396/why-cant-variables-be-declared-in-a-switch-statement
+            int n = gtk_notebook_get_n_pages(notebook);
+            int k = gtk_notebook_get_current_page(notebook);
+            int l = (n + k - 1) % n;
+            gtk_notebook_set_current_page(notebook, l);
+            break;
+        case next_tab:;
+            int m = gtk_notebook_get_n_pages(notebook);
+            int i = gtk_notebook_get_current_page(notebook);
+            int j = (i + 1) % m;
+            gtk_notebook_set_current_page(notebook, j);
+            break;
+        case close_tab:
+            gtk_notebook_remove_page(notebook, gtk_notebook_get_current_page(notebook));
+            num_tabs -= 1;
+
+            switch (gtk_notebook_get_n_pages(notebook)) {
+                case 0:
+                    exit(0);
+                    break;
+                case 1:
+                    gtk_notebook_set_show_tabs(notebook, false);
+                    break;
+            }
+
+            break;
+        case toggle_fullscreen:
+            if (is_fullscreen)
+                gtk_window_unfullscreen(window);
+            else
+                gtk_window_fullscreen(window);
+            is_fullscreen = !is_fullscreen;
+            break;
+        case show_searchbar:
+            toggle_bar(notebook, _SEARCH);
+            break;
+        case show_finder:
+            toggle_bar(notebook, _FIND);
+            break;
+
+        case finder_next:
+            webkit_find_controller_search_next(webkit_web_view_get_find_controller(view));
+            break;
+        case finder_prev:
+            webkit_find_controller_search_previous(webkit_web_view_get_find_controller(view));
+            break;
+
+        case new_tab:
+            notebook_create_new_tab(notebook, NULL);
+            gtk_notebook_set_show_tabs(notebook, true);
+            toggle_bar(notebook, _SEARCH);
+            break;
+
+        case hide_bar:
+            toggle_bar(notebook, _HIDDEN);
+            break;
+
+        case prettify: {
+            if (READABILITY_ENABLED) {
+                char* readability_js = malloc(READABILITY_N + 1);
+                read_readability_js(readability_js);
+                webkit_web_view_evaluate_javascript(view, readability_js, -1, NULL, "rosenrot-readability-plugin", NULL, NULL, NULL);
+                free(readability_js);
+            }
+            break;
+        }
+    }
+
+    return 1;
+}
+// Listen to key presses and call shortcuts if needed.
+int handle_signal_keypress(void* self, GdkEvent* event, GtkNotebook* notebook)
+{
+    (void)self;
+
+    guint event_keyval = 0;
+    gdk_event_get_keyval(event, &event_keyval);
+    GdkModifierType event_state = 0;
+    gdk_event_get_state(event, &event_state);
+
+    if (0) {
+        printf("Keypress state: %d\n", event_state);
+        printf("Keypress value: %d\n", event_keyval);
+    }
+
+    for (int i = 0; i < sizeof(shortcut) / sizeof(shortcut[0]); i++)
+        if ((event_state & shortcut[i].mod || shortcut[i].mod == 0x0) && event_keyval == shortcut[i].key)
+            return handle_shortcut(shortcut[i].id, notebook);
+    /*
+    If I wanted to bind button presses, like the extra button in the mouse,
+    I would have to bind the button-press-event signal instead.
+    Some links in case I go down that road:
+    - https://docs.gtk.org/gtk3/signal.Widget.button-press-event.html
+    - https://docs.gtk.org/gdk3/union.Event.html
+    - https://docs.gtk.org/gdk3/struct.EventButton.html
+    */
+    // This API is deprecated in GTK4 :(.
+    return 0;
+}
+
+int main(int argc, char** argv)
+{
+    /* Initialize GTK in general */
+    #if GTK_NUM == 3
+        gtk_init(NULL, NULL); // https://docs.gtk.org/gtk3/func.init.html
+    #elif GTK_NUM == 4
+        gtk_init()
+    #endif
+    g_object_set(gtk_settings_get_default(), GTK_SETTINGS_CONFIG_H, NULL); // https://docs.gtk.org/gobject/method.Object.set.html
+    GtkCssProvider* css = gtk_css_provider_new();
+    gtk_css_provider_load_from_path(css, "/opt/rosenrot/style.css", NULL);
+    #if GTK_NUM == 3
+        gtk_style_context_add_provider_for_screen(gdk_screen_get_default(), GTK_STYLE_PROVIDER(css), 800); /* might change with GTK4/webkitgtk6.0 */
+    #elif GTK_NUM == 4
+        gtk_style_context_add_provider_for_display(gdk_screen_get_default(), GTK_STYLE_PROVIDER(css), 800); /* might change with GTK4/webkitgtk6.0 */
+    #endif
+
+    /* Initialize GTK objects. These are declared as static globals at the top of this file */
+    // Notebook
+    notebook = GTK_NOTEBOOK(gtk_notebook_new());
+    gtk_notebook_set_show_tabs(notebook, false);
+    gtk_notebook_set_show_border(notebook, false);
+
+    // Window
+    window = GTK_WINDOW(gtk_window_new(0));
+    gtk_window_set_default_size(window, WIDTH, HEIGHT);
+    g_signal_connect(window, "key-press-event", G_CALLBACK(handle_signal_keypress), notebook);
+    g_signal_connect(window, "destroy", G_CALLBACK(exit), notebook);
+
+    #if GTK_NUM == 3
+        gtk_container_add(GTK_CONTAINER(window), GTK_WIDGET(notebook)); /* deprecated in GTK */
+    #elif GTK_NUM == 4
+        gtk_window_set_child(GTK_CONTAINER(window), GTK_WIDGET(notebook))
+    #endif
+
+    // Bar
+    bar.line_text = GTK_ENTRY_BUFFER(gtk_entry_buffer_new("", 0));
+    bar.line = GTK_ENTRY(gtk_entry_new_with_buffer(bar.line_text));
+    gtk_entry_set_alignment(bar.line, 0.48);
+    gtk_widget_set_size_request(GTK_WIDGET(bar.line), BAR_SIZE, -1);
+    g_signal_connect(bar.line, "activate", G_CALLBACK(handle_signal_bar_press_enter), notebook);
+
+    bar.widget = GTK_HEADER_BAR(gtk_header_bar_new());
+    #if GTK_NUM == 3
+        gtk_header_bar_set_custom_title(bar.widget, GTK_WIDGET(bar.line));
+    #elif GTK_NUM == 4
+        gtk_header_bar_set_title_widget(bar.widget, GTK_WIDGET(bar.line));
+    #endif
+    gtk_window_set_titlebar(window, GTK_WIDGET(bar.widget));
+
+    /* Load first tab */
+    char* first_uri = argc > 1 ? argv[1] : HOME;
+    notebook_create_new_tab(notebook, first_uri);
+
+    /* Show to user */
+    gtk_widget_show_all(GTK_WIDGET(window));
+    if (argc != 0) gtk_widget_hide(GTK_WIDGET(bar.widget));
+
+    /* Deal with more tabs */
+    if (argc > 2) {
+        gtk_notebook_set_show_tabs(notebook, true);
+        for (int i = 2; i < argc; i++) {
+            notebook_create_new_tab(notebook, argv[i]);
+        }
+    }
+
+    gtk_main(); /* deprecated in GKT4: https://docs.gtk.org/gtk4/migrating-3to4.html#stop-using-gtk_main-and-related-apis */
+    //
+    while (g_list_model_get_n_items (gtk_window_get_toplevels ()) > 0)
+      g_main_context_iteration (NULL, TRUE);
+}