diff --git a/pixstrip-gtk/src/app.rs b/pixstrip-gtk/src/app.rs
index 1d26e53..99663f8 100644
--- a/pixstrip-gtk/src/app.rs
+++ b/pixstrip-gtk/src/app.rs
@@ -659,6 +659,114 @@ fn build_ui(app: &adw::Application) {
             }
         }
     }
+
+    // Start watch folder monitoring for active folders
+    start_watch_folder_monitoring(&ui);
+}
+
+fn start_watch_folder_monitoring(ui: &WizardUi) {
+    let config_store = pixstrip_core::storage::ConfigStore::new();
+    let config = config_store.load().unwrap_or_default();
+
+    let active_folders: Vec<_> = config.watch_folders.iter()
+        .filter(|f| f.active && f.path.exists())
+        .cloned()
+        .collect();
+
+    if active_folders.is_empty() {
+        return;
+    }
+
+    let (tx, rx) = std::sync::mpsc::channel::<pixstrip_core::watcher::WatchEvent>();
+
+    // Start a watcher for each active folder
+    for folder in &active_folders {
+        let watcher = pixstrip_core::watcher::FolderWatcher::new();
+        let folder_tx = tx.clone();
+        if let Err(e) = watcher.start(folder, folder_tx) {
+            eprintln!("Failed to start watching {}: {}", folder.path.display(), e);
+            continue;
+        }
+        // Leak the watcher so it stays alive for the lifetime of the app
+        std::mem::forget(watcher);
+    }
+
+    // Build a lookup from folder path to preset name
+    let folder_presets: std::collections::HashMap<std::path::PathBuf, String> = active_folders
+        .iter()
+        .map(|f| (f.path.clone(), f.preset_name.clone()))
+        .collect();
+
+    let toast_overlay = ui.toast_overlay.clone();
+
+    // Poll the channel from the main loop
+    glib::timeout_add_local(std::time::Duration::from_millis(500), move || {
+        let mut batch: Vec<(std::path::PathBuf, String)> = Vec::new();
+
+        // Drain all pending events
+        while let Ok(event) = rx.try_recv() {
+            match event {
+                pixstrip_core::watcher::WatchEvent::NewImage(path) => {
+                    // Find which watch folder this belongs to
+                    for (folder_path, preset_name) in &folder_presets {
+                        if path.starts_with(folder_path) {
+                            batch.push((path.clone(), preset_name.clone()));
+                            break;
+                        }
+                    }
+                }
+                pixstrip_core::watcher::WatchEvent::Error(e) => {
+                    eprintln!("Watch folder error: {}", e);
+                }
+            }
+        }
+
+        if !batch.is_empty() {
+            // Group by preset name and process
+            let preset_store = pixstrip_core::storage::PresetStore::new();
+            let mut by_preset: std::collections::HashMap<String, Vec<std::path::PathBuf>> =
+                std::collections::HashMap::new();
+            for (path, preset) in batch {
+                by_preset.entry(preset).or_default().push(path);
+            }
+
+            for (preset_name, files) in by_preset {
+                if let Ok(presets) = preset_store.list() {
+                    if let Some(preset) = presets.iter().find(|p| p.name == preset_name) {
+                        let count = files.len();
+                        let preset = preset.clone();
+                        std::thread::spawn(move || {
+                            // Build output dir next to the first file
+                            let output_dir = files.first()
+                                .and_then(|f| f.parent())
+                                .map(|p| p.join("processed"))
+                                .unwrap_or_else(|| std::path::PathBuf::from("processed"));
+                            let input_dir = files.first()
+                                .and_then(|f| f.parent())
+                                .unwrap_or_else(|| std::path::Path::new("."))
+                                .to_path_buf();
+                            let mut job = preset.to_job(&input_dir, &output_dir);
+                            for file in &files {
+                                job.add_source(file);
+                            }
+                            let executor = pixstrip_core::executor::PipelineExecutor::new();
+                            let _ = executor.execute(&job, |_| {});
+                        });
+
+                        let toast = adw::Toast::new(&format!(
+                            "Watch: processing {} new image{}",
+                            count,
+                            if count == 1 { "" } else { "s" }
+                        ));
+                        toast.set_timeout(3);
+                        toast_overlay.add_toast(toast);
+                    }
+                }
+            }
+        }
+
+        glib::ControlFlow::Continue
+    });
 }
 
 fn build_menu() -> gtk::gio::Menu {