diff --git a/config.h b/config.h
index 0b8f545..33d490e 100644
--- a/config.h
+++ b/config.h
@@ -12,3 +12,9 @@ std::string get_config_folder();
 void create_config_folders_if_necessary();
 Config load_config();
 void write_config(const Config& config);
+
+constexpr bool operator!=(const Config& lhs, const Config& rhs) {
+    return lhs.logcat_command != rhs.logcat_command
+        || lhs.normal_font_size != rhs.normal_font_size
+        || lhs.monospace_font_size != rhs.monospace_font_size;
+}
diff --git a/event_loop.cpp b/event_loop.cpp
index 0f689a6..93b8c80 100644
--- a/event_loop.cpp
+++ b/event_loop.cpp
@@ -11,15 +11,6 @@
     #include "windows/debug.h"
 #endif
 
-static inline void write_config_and_update_structures(const Config& config) {
-    try {
-        write_config(config);
-    } catch (const std::exception& e) {
-        log(std::string("Failed to write config: ") + e.what());
-        return;
-    }
-}
-
 static inline void check_for_logcat_items(LogcatThread& logcat_thread, std::vector<LogcatEntry>& filtered_logcat_entries) {
     LogcatThreadItem* logcat_thread_item;
 
@@ -36,7 +27,8 @@ static inline void check_for_logcat_items(LogcatThread& logcat_thread, std::vect
 }
 
 
-void event_loop(ImFont* monospace_font, Config& config, float* config_write_timer, LogcatThread& logcat_thread, bool* run_event_loop) {
+void event_loop(ImFont* monospace_font, Config& active_config, LogcatThread& logcat_thread, bool* run_event_loop) {
+    static Config inactive_config;
     static bool show_settings_window = false;
     static bool show_logs_window = false;
     static size_t log_entries_read = 0;
@@ -49,13 +41,7 @@ void event_loop(ImFont* monospace_font, Config& config, float* config_write_time
 #endif
 
     if (show_settings_window) {
-        settings_window(config, config_write_timer, &show_settings_window);
-    }
-    if (*config_write_timer > 0.0f) {
-        *config_write_timer -= ImGui::GetIO().DeltaTime;
-        if (*config_write_timer <= 0.0f) {
-            write_config_and_update_structures(config);
-        }
+        settings_window(active_config, inactive_config, &show_settings_window);
     }
 
     if (show_logs_window) {
@@ -67,5 +53,8 @@ void event_loop(ImFont* monospace_font, Config& config, float* config_write_time
     }
 
     // log_entries must not be mutated until the show logs button
-    main_window(log_entries_read == log_entries.size(), monospace_font, filtered_logcat_entries, &show_settings_window, &show_logs_window, run_event_loop);
+    main_window(log_entries_read == log_entries.size(),
+        monospace_font, filtered_logcat_entries,
+        active_config, inactive_config, &show_settings_window,
+        &show_logs_window, run_event_loop);
 }
diff --git a/event_loop.h b/event_loop.h
index c9a4103..683a7f3 100644
--- a/event_loop.h
+++ b/event_loop.h
@@ -5,4 +5,4 @@
 #include "config.h"
 #include "logcat_thread.h"
 
-void event_loop(ImFont* monospace_font, Config& config, float* config_write_timer, LogcatThread& logcat_thread, bool* run_event_loop);
+void event_loop(ImFont* monospace_font, Config& active_config, LogcatThread& logcat_thread, bool* run_event_loop);
diff --git a/main.cpp b/main.cpp
index b63e322..ff35cf7 100644
--- a/main.cpp
+++ b/main.cpp
@@ -131,7 +131,6 @@ int main(int, char**) {
 
     // Main loop
     bool run_event_loop = true;
-    float config_write_timer = 0.0f;
     LogcatThread logcat_thread = [&]() {
         try {
             return LogcatThread();
@@ -162,7 +161,7 @@ int main(int, char**) {
         ImGui_ImplSDL2_NewFrame();
         ImGui::NewFrame();
 
-        event_loop(monospace_font, config, &config_write_timer, logcat_thread, &run_event_loop);
+        event_loop(monospace_font, config, logcat_thread, &run_event_loop);
 
         // Rendering
         ImGui::Render();
@@ -182,14 +181,6 @@ int main(int, char**) {
     SDL_DestroyWindow(window);
     SDL_Quit();
 
-    if (config_write_timer > 0.0f) {
-        try {
-            write_config(config);
-        } catch (const std::exception& e) {
-            fprintf(stderr, "Failed to write config: %s\n", e.what());
-            return 1;
-        }
-    }
     logcat_thread.request_stop();
     logcat_thread.join();
 
diff --git a/windows/main.cpp b/windows/main.cpp
index e522f79..9d35097 100644
--- a/windows/main.cpp
+++ b/windows/main.cpp
@@ -50,13 +50,14 @@ static inline void main_scrolling_region(ImFont* monospace_font, std::vector<Log
 }
 
 void main_window(bool latest_log_entries_read, ImFont* monospace_font, std::vector<LogcatEntry>& filtered_logcat_entries,
-        bool* show_settings_window, bool* show_logs_window, bool* run_event_loop) {
+        const Config& active_config, Config& inactive_config, bool* show_settings_window, bool* show_logs_window, bool* run_event_loop) {
     if (!ImGui::Begin("LogMeow", run_event_loop)) {
         ImGui::End();
         return;
     }
 
-    if (ImGui::Button("Settings")) {
+    if (ImGui::Button("Settings") && !*show_settings_window) {
+        inactive_config = active_config;
         *show_settings_window = true;
     }
 
diff --git a/windows/main.h b/windows/main.h
index 2092149..1939e11 100644
--- a/windows/main.h
+++ b/windows/main.h
@@ -3,7 +3,8 @@
 #include <imgui.h>
 #include <vector>
 
+#include "../config.h"
 #include "../logcat_entry.h"
 
 void main_window(bool latest_log_entries_read, ImFont* monospace_font, std::vector<LogcatEntry>& filtered_logcat_entries,
-        bool* show_settings_window, bool* show_logs_window, bool* run_event_loop);
+        const Config& active_config, Config& inactive_config, bool* show_settings_window, bool* show_logs_window, bool* run_event_loop);
diff --git a/windows/settings.cpp b/windows/settings.cpp
index abc7e4f..f0baa44 100644
--- a/windows/settings.cpp
+++ b/windows/settings.cpp
@@ -4,24 +4,48 @@
 #include "../config.h"
 #include "settings.h"
 
-void settings_window(Config& config, float* config_write_timer, bool* p_open) {
-    if (!ImGui::Begin("Settings", p_open)) {
+static void write_config_and_update_structures(const Config& config) {
+    try {
+        write_config(config);
+    } catch (const std::exception& e) {
+        log(std::string("Failed to write config: ") + e.what());
+        return;
+    }
+}
+
+void settings_window(Config& active_config, Config& inactive_config, bool* p_open) {
+    ImGuiWindowFlags flags = active_config != inactive_config
+        ? ImGuiWindowFlags_UnsavedDocument
+        : 0;
+    if (!ImGui::Begin("Settings", p_open, flags)) {
         ImGui::End();
         return;
     }
     // TODO actually have process control
     ImGui::Text("Logcat command only takes effect when logcat is not running");
-    if (ImGui::InputTextWithHint("Logcat command", "adb logcat -Dv 'threadtime UTC epoch usec uid'", &config.logcat_command)) {
-        *config_write_timer = *config_write_timer > 0.0f ? *config_write_timer : 5.0f;
-    }
+    ImGui::InputTextWithHint("Logcat command", "adb logcat -Dv 'threadtime UTC epoch usec uid'", &inactive_config.logcat_command);
+
     ImGui::Text("Font sizes only take effect when LogMeow is restarted");
 #ifdef USE_FONTCONFIG
-    if (ImGui::InputFloat("Normal font size", &config.normal_font_size, 0.5f, 1.0f, "%.3f")) {
-        *config_write_timer = *config_write_timer > 0.0f ? *config_write_timer : 5.0f;
-    }
+    ImGui::InputFloat("Normal font size", &inactive_config.normal_font_size, 0.5f, 1.0f, "%.3f");
 #endif
-    if (ImGui::InputFloat("Monospace font size", &config.monospace_font_size, 0.5f, 1.0f, "%.3f")) {
-        *config_write_timer = *config_write_timer > 0.0f ? *config_write_timer : 5.0f;
+    ImGui::InputFloat("Monospace font size", &inactive_config.monospace_font_size, 0.5f, 1.0f, "%.3f");
+
+    ImGui::Separator();
+    ImVec2 button_size(4 * ImGui::GetFontSize(), 0);
+    if (ImGui::Button("OK", button_size)) {
+        active_config = inactive_config;
+        write_config_and_update_structures(active_config);
+        *p_open = false;
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Cancel", button_size)) {
+        *p_open = false;
+    }
+    ImGui::SameLine();
+    if (ImGui::Button("Apply", button_size)) {
+        active_config = inactive_config;
+        write_config_and_update_structures(active_config);
     }
     ImGui::End();
 }
diff --git a/windows/settings.h b/windows/settings.h
index 2e4237c..557575a 100644
--- a/windows/settings.h
+++ b/windows/settings.h
@@ -2,4 +2,4 @@
 
 #include "../config.h"
 
-void settings_window(Config& config, float* config_write_timer, bool* p_open);
+void settings_window(Config& active_config, Config& inactive_config, bool* p_open);