diff --git a/src/lib/components/CropOverlay.svelte b/src/lib/components/CropOverlay.svelte
new file mode 100644
index 0000000..d06f4e2
--- /dev/null
+++ b/src/lib/components/CropOverlay.svelte
@@ -0,0 +1,244 @@
+<script lang="ts">
+	import type { CropRegion } from '$lib/types';
+
+	interface Props {
+		imageWidth: number;
+		imageHeight: number;
+		targetAspect: number;
+		region: CropRegion | undefined;
+		onRegionChange: (region: CropRegion) => void;
+	}
+
+	let { imageWidth, imageHeight, targetAspect, region, onRegionChange }: Props = $props();
+
+	let containerRef: HTMLDivElement;
+	let isDragging = $state(false);
+	let isResizing = $state(false);
+	let resizeHandle = $state<string | null>(null);
+	let dragStart = $state({ x: 0, y: 0, regionX: 0, regionY: 0 });
+
+	// Initialize region if not set
+	const currentRegion = $derived<CropRegion>(() => {
+		if (region) return region;
+		// Default: centered crop that fills as much as possible while maintaining aspect ratio
+		const imageAspect = imageWidth / imageHeight;
+		let width: number, height: number;
+
+		if (imageAspect > targetAspect) {
+			height = imageHeight;
+			width = height * targetAspect;
+		} else {
+			width = imageWidth;
+			height = width / targetAspect;
+		}
+
+		return {
+			x: (imageWidth - width) / 2,
+			y: (imageHeight - height) / 2,
+			width,
+			height
+		};
+	});
+
+	// Convert image coordinates to percentage for display
+	const regionStyle = $derived(() => {
+		const r = currentRegion();
+		return {
+			left: `${(r.x / imageWidth) * 100}%`,
+			top: `${(r.y / imageHeight) * 100}%`,
+			width: `${(r.width / imageWidth) * 100}%`,
+			height: `${(r.height / imageHeight) * 100}%`
+		};
+	});
+
+	function getMousePosition(e: MouseEvent | TouchEvent): { x: number; y: number } {
+		if (!containerRef) return { x: 0, y: 0 };
+		const rect = containerRef.getBoundingClientRect();
+		const clientX = 'touches' in e ? e.touches[0].clientX : e.clientX;
+		const clientY = 'touches' in e ? e.touches[0].clientY : e.clientY;
+
+		// Convert to image coordinates
+		const x = ((clientX - rect.left) / rect.width) * imageWidth;
+		const y = ((clientY - rect.top) / rect.height) * imageHeight;
+		return { x, y };
+	}
+
+	function handleDragStart(e: MouseEvent | TouchEvent): void {
+		e.preventDefault();
+		e.stopPropagation();
+		isDragging = true;
+		const pos = getMousePosition(e);
+		const r = currentRegion();
+		dragStart = { x: pos.x, y: pos.y, regionX: r.x, regionY: r.y };
+		addGlobalListeners();
+	}
+
+	function handleResizeStart(e: MouseEvent | TouchEvent, handle: string): void {
+		e.preventDefault();
+		e.stopPropagation();
+		isResizing = true;
+		resizeHandle = handle;
+		const pos = getMousePosition(e);
+		const r = currentRegion();
+		dragStart = { x: pos.x, y: pos.y, regionX: r.x, regionY: r.y };
+		addGlobalListeners();
+	}
+
+	function handleMove(e: MouseEvent | TouchEvent): void {
+		if (!isDragging && !isResizing) return;
+		e.preventDefault();
+
+		const pos = getMousePosition(e);
+		const dx = pos.x - dragStart.x;
+		const dy = pos.y - dragStart.y;
+		const r = currentRegion();
+
+		if (isDragging) {
+			// Move the crop region
+			let newX = dragStart.regionX + dx;
+			let newY = dragStart.regionY + dy;
+
+			// Clamp to image bounds
+			newX = Math.max(0, Math.min(imageWidth - r.width, newX));
+			newY = Math.max(0, Math.min(imageHeight - r.height, newY));
+
+			onRegionChange({ ...r, x: newX, y: newY });
+		} else if (isResizing && resizeHandle) {
+			// Resize while maintaining aspect ratio
+			let newRegion = { ...r };
+
+			if (resizeHandle.includes('e')) {
+				newRegion.width = Math.max(50, r.width + dx);
+				newRegion.height = newRegion.width / targetAspect;
+			} else if (resizeHandle.includes('w')) {
+				const newWidth = Math.max(50, r.width - dx);
+				newRegion.x = r.x + (r.width - newWidth);
+				newRegion.width = newWidth;
+				newRegion.height = newWidth / targetAspect;
+			}
+
+			if (resizeHandle.includes('s')) {
+				newRegion.height = Math.max(50, r.height + dy);
+				newRegion.width = newRegion.height * targetAspect;
+			} else if (resizeHandle.includes('n')) {
+				const newHeight = Math.max(50, r.height - dy);
+				newRegion.y = r.y + (r.height - newHeight);
+				newRegion.height = newHeight;
+				newRegion.width = newHeight * targetAspect;
+			}
+
+			// Clamp to image bounds
+			if (newRegion.x < 0) {
+				newRegion.width += newRegion.x;
+				newRegion.height = newRegion.width / targetAspect;
+				newRegion.x = 0;
+			}
+			if (newRegion.y < 0) {
+				newRegion.height += newRegion.y;
+				newRegion.width = newRegion.height * targetAspect;
+				newRegion.y = 0;
+			}
+			if (newRegion.x + newRegion.width > imageWidth) {
+				newRegion.width = imageWidth - newRegion.x;
+				newRegion.height = newRegion.width / targetAspect;
+			}
+			if (newRegion.y + newRegion.height > imageHeight) {
+				newRegion.height = imageHeight - newRegion.y;
+				newRegion.width = newRegion.height * targetAspect;
+			}
+
+			onRegionChange(newRegion);
+		}
+	}
+
+	function handleEnd(): void {
+		isDragging = false;
+		isResizing = false;
+		resizeHandle = null;
+		removeGlobalListeners();
+	}
+
+	function addGlobalListeners(): void {
+		window.addEventListener('mousemove', handleMove);
+		window.addEventListener('mouseup', handleEnd);
+		window.addEventListener('touchmove', handleMove);
+		window.addEventListener('touchend', handleEnd);
+	}
+
+	function removeGlobalListeners(): void {
+		window.removeEventListener('mousemove', handleMove);
+		window.removeEventListener('mouseup', handleEnd);
+		window.removeEventListener('touchmove', handleMove);
+		window.removeEventListener('touchend', handleEnd);
+	}
+</script>
+
+<div bind:this={containerRef} class="absolute inset-0">
+	<!-- Darkened overlay outside crop area -->
+	<div class="absolute inset-0 pointer-events-none">
+		<!-- Top -->
+		<div
+			class="absolute left-0 right-0 top-0 bg-black/50"
+			style="height: {regionStyle().top}"
+		></div>
+		<!-- Bottom -->
+		<div
+			class="absolute left-0 right-0 bottom-0 bg-black/50"
+			style="height: calc(100% - {regionStyle().top} - {regionStyle().height})"
+		></div>
+		<!-- Left -->
+		<div
+			class="absolute left-0 bg-black/50"
+			style="top: {regionStyle().top}; width: {regionStyle().left}; height: {regionStyle().height}"
+		></div>
+		<!-- Right -->
+		<div
+			class="absolute right-0 bg-black/50"
+			style="top: {regionStyle().top}; width: calc(100% - {regionStyle().left} - {regionStyle().width}); height: {regionStyle().height}"
+		></div>
+	</div>
+
+	<!-- Crop region -->
+	<!-- svelte-ignore a11y_no_static_element_interactions -->
+	<div
+		class="absolute border-2 border-white shadow-lg cursor-move"
+		style="left: {regionStyle().left}; top: {regionStyle().top}; width: {regionStyle().width}; height: {regionStyle().height}"
+		onmousedown={handleDragStart}
+		ontouchstart={handleDragStart}
+	>
+		<!-- Grid lines -->
+		<div class="absolute inset-0 pointer-events-none">
+			<div class="absolute left-1/3 top-0 bottom-0 w-px bg-white/40"></div>
+			<div class="absolute left-2/3 top-0 bottom-0 w-px bg-white/40"></div>
+			<div class="absolute top-1/3 left-0 right-0 h-px bg-white/40"></div>
+			<div class="absolute top-2/3 left-0 right-0 h-px bg-white/40"></div>
+		</div>
+
+		<!-- Resize handles -->
+		<!-- Corners -->
+		<!-- svelte-ignore a11y_no_static_element_interactions -->
+		<div
+			class="absolute -top-2 -left-2 w-4 h-4 bg-white border border-grey-400 rounded-sm cursor-nw-resize"
+			onmousedown={(e) => handleResizeStart(e, 'nw')}
+			ontouchstart={(e) => handleResizeStart(e, 'nw')}
+		></div>
+		<!-- svelte-ignore a11y_no_static_element_interactions -->
+		<div
+			class="absolute -top-2 -right-2 w-4 h-4 bg-white border border-grey-400 rounded-sm cursor-ne-resize"
+			onmousedown={(e) => handleResizeStart(e, 'ne')}
+			ontouchstart={(e) => handleResizeStart(e, 'ne')}
+		></div>
+		<!-- svelte-ignore a11y_no_static_element_interactions -->
+		<div
+			class="absolute -bottom-2 -left-2 w-4 h-4 bg-white border border-grey-400 rounded-sm cursor-sw-resize"
+			onmousedown={(e) => handleResizeStart(e, 'sw')}
+			ontouchstart={(e) => handleResizeStart(e, 'sw')}
+		></div>
+		<!-- svelte-ignore a11y_no_static_element_interactions -->
+		<div
+			class="absolute -bottom-2 -right-2 w-4 h-4 bg-white border border-grey-400 rounded-sm cursor-se-resize"
+			onmousedown={(e) => handleResizeStart(e, 'se')}
+			ontouchstart={(e) => handleResizeStart(e, 'se')}
+		></div>
+	</div>
+</div>
diff --git a/src/lib/components/EditImageModal.svelte b/src/lib/components/EditImageModal.svelte
index 0240ba6..8b8e4d0 100644
--- a/src/lib/components/EditImageModal.svelte
+++ b/src/lib/components/EditImageModal.svelte
@@ -167,6 +167,7 @@
 						config={localConfig}
 						onPreviewUpdate={handlePreviewUpdate}
 						onProcessingChange={handleProcessingChange}
+						onConfigChange={handleConfigChange}
 					/>
 				</div>
 
diff --git a/src/lib/components/ImagePreview.svelte b/src/lib/components/ImagePreview.svelte
index d02dd61..6e18725 100644
--- a/src/lib/components/ImagePreview.svelte
+++ b/src/lib/components/ImagePreview.svelte
@@ -1,7 +1,8 @@
 <script lang="ts">
 	import { Loader2 } from 'lucide-svelte';
-	import type { ImageEntry, Device, PipelineConfig } from '$lib/types';
+	import type { ImageEntry, Device, PipelineConfig, CropRegion } from '$lib/types';
 	import { processImageWithPipeline } from '$lib/processing/pipeline';
+	import CropOverlay from './CropOverlay.svelte';
 
 	interface Props {
 		image: ImageEntry;
@@ -9,18 +10,27 @@
 		config: PipelineConfig;
 		onPreviewUpdate: (dataUrl: string) => void;
 		onProcessingChange: (processing: boolean) => void;
+		onConfigChange?: (config: PipelineConfig) => void;
 	}
 
-	let { image, device, config, onPreviewUpdate, onProcessingChange }: Props = $props();
+	let { image, device, config, onPreviewUpdate, onProcessingChange, onConfigChange }: Props = $props();
 
 	let previewDataUrl = $state<string | null>(null);
 	let isProcessing = $state(false);
 	let debounceTimer: ReturnType<typeof setTimeout> | null = null;
 
+	const isManualCrop = $derived(config.crop.enabled && config.crop.mode === 'manual');
+	const targetAspect = $derived(device.width / device.height);
+
 	// Track config changes and trigger debounced processing
 	$effect(() => {
-		// Access config to create dependency
-		const _ = JSON.stringify(config);
+		// Access config to create dependency (but skip processing in manual crop mode without region)
+		const configStr = JSON.stringify(config);
+
+		// Don't process if in manual crop mode - wait for region to be set
+		if (isManualCrop && !config.crop.region) {
+			return;
+		}
 
 		// Clear existing timer
 		if (debounceTimer) {
@@ -63,12 +73,35 @@
 			previewDataUrl = image.processedDataUrl;
 		}
 	});
+
+	function handleCropRegionChange(region: CropRegion): void {
+		if (onConfigChange) {
+			onConfigChange({
+				...config,
+				crop: { ...config.crop, region }
+			});
+		}
+	}
 </script>
 
 <div class="flex flex-col items-center gap-4">
 	<!-- Preview container -->
 	<div class="relative w-full max-w-md aspect-[3/4] bg-grey-100 rounded-lg overflow-hidden shadow-inner">
-		{#if previewDataUrl}
+		{#if isManualCrop && image.originalDataUrl && image.originalDimensions}
+			<!-- Show original image with crop overlay in manual mode -->
+			<img
+				src={image.originalDataUrl}
+				alt="Original"
+				class="absolute inset-0 w-full h-full object-contain"
+			/>
+			<CropOverlay
+				imageWidth={image.originalDimensions.width}
+				imageHeight={image.originalDimensions.height}
+				{targetAspect}
+				region={config.crop.region}
+				onRegionChange={handleCropRegionChange}
+			/>
+		{:else if previewDataUrl}
 			<img
 				src={previewDataUrl}
 				alt="Preview"
@@ -103,11 +136,8 @@
 				{device.width} × {device.height}
 			</p>
 		{/if}
+		{#if isManualCrop}
+			<p class="text-xs text-accent mt-1">Drag to position, drag corners to resize</p>
+		{/if}
 	</div>
-
-	<!-- Original vs Preview toggle (future enhancement) -->
-	<!-- <div class="flex items-center gap-2">
-		<button class="text-sm text-grey-500 hover:text-ink">Original</button>
-		<button class="text-sm text-accent font-medium">Preview</button>
-	</div> -->
 </div>
diff --git a/src/lib/components/PipelinePanel.svelte b/src/lib/components/PipelinePanel.svelte
index 07bcdec..161f753 100644
--- a/src/lib/components/PipelinePanel.svelte
+++ b/src/lib/components/PipelinePanel.svelte
@@ -47,7 +47,7 @@
 		{ value: 'center', label: 'Center' },
 		{ value: 'top', label: 'Top' },
 		{ value: 'bottom', label: 'Bottom' },
-		{ value: 'manual', label: 'Manual (coming soon)' }
+		{ value: 'manual', label: 'Manual' }
 	];
 
 	const resizeModes: { value: ResizeMode; label: string }[] = [
diff --git a/src/lib/processing/photonWorker.ts b/src/lib/processing/photonWorker.ts
index a4231e9..6f1470d 100644
--- a/src/lib/processing/photonWorker.ts
+++ b/src/lib/processing/photonWorker.ts
@@ -199,24 +199,47 @@ async function processImage(
 			const width = img.get_width();
 			const height = img.get_height();
 			const targetAspect = device.width / device.height;
-			const currentAspect = width / height;
 
 			let cropX1: number, cropY1: number, cropX2: number, cropY2: number;
 
-			if (currentAspect > targetAspect) {
-				const newWidth = Math.max(1, Math.floor(height * targetAspect));
-				const xOffset = Math.floor((width - newWidth) / 2);
-				cropX1 = Math.max(0, xOffset);
-				cropY1 = 0;
-				cropX2 = Math.min(width, cropX1 + newWidth);
-				cropY2 = height;
+			if (config.crop.mode === 'manual' && config.crop.region) {
+				// Manual crop: use the provided region
+				const region = config.crop.region;
+				cropX1 = Math.max(0, Math.round(region.x));
+				cropY1 = Math.max(0, Math.round(region.y));
+				cropX2 = Math.min(width, Math.round(region.x + region.width));
+				cropY2 = Math.min(height, Math.round(region.y + region.height));
 			} else {
-				const newHeight = Math.max(1, Math.floor(width / targetAspect));
-				const yOffset = Math.floor((height - newHeight) / 2);
-				cropX1 = 0;
-				cropY1 = Math.max(0, yOffset);
-				cropX2 = width;
-				cropY2 = Math.min(height, cropY1 + newHeight);
+				// Auto crop modes: center, top, bottom
+				const currentAspect = width / height;
+
+				if (currentAspect > targetAspect) {
+					const newWidth = Math.max(1, Math.floor(height * targetAspect));
+					let xOffset: number;
+					if (config.crop.mode === 'top' || config.crop.mode === 'bottom') {
+						xOffset = Math.floor((width - newWidth) / 2);
+					} else {
+						xOffset = Math.floor((width - newWidth) / 2);
+					}
+					cropX1 = Math.max(0, xOffset);
+					cropY1 = 0;
+					cropX2 = Math.min(width, cropX1 + newWidth);
+					cropY2 = height;
+				} else {
+					const newHeight = Math.max(1, Math.floor(width / targetAspect));
+					let yOffset: number;
+					if (config.crop.mode === 'top') {
+						yOffset = 0;
+					} else if (config.crop.mode === 'bottom') {
+						yOffset = height - newHeight;
+					} else {
+						yOffset = Math.floor((height - newHeight) / 2);
+					}
+					cropX1 = 0;
+					cropY1 = Math.max(0, yOffset);
+					cropX2 = width;
+					cropY2 = Math.min(height, cropY1 + newHeight);
+				}
 			}
 
 			if (cropX2 > cropX1 && cropY2 > cropY1) {