diff --git a/pages/index.vue b/pages/index.vue
index ae58d7f..af0ade1 100644
--- a/pages/index.vue
+++ b/pages/index.vue
@@ -127,7 +127,7 @@
           <div class="mt-4 space-y-4">
             <div>
               <p class="mb-2 text-xs uppercase tracking-wider text-zinc-500">Aspect ratio / resolution</p>
-              <div class="grid grid-cols-1 gap-2 sm:grid-cols-3">
+              <div class="grid grid-cols-2 gap-2 lg:grid-cols-4">
                 <button
                   v-for="option in aspects"
                   :key="option.id"
@@ -137,10 +137,10 @@
                   @click="aspect = option.id"
                 >
                   <span class="block font-semibold">{{ option.label }}</span>
-                  <span class="text-xs text-zinc-400">{{ option.hint }}</span>
+                  <span class="text-xs text-zinc-400">{{ option.id === 'auto' ? autoHint : option.hint }}</span>
                 </button>
               </div>
-              <p class="mt-2 text-xs text-zinc-500">Output {{ outputSize.width }} × {{ outputSize.height }}</p>
+              <p class="mt-2 text-xs text-zinc-500">Output {{ outputSize.width }} × {{ outputSize.height }}{{ aspect === 'auto' ? ' · matching the still' : '' }}</p>
             </div>
             <div>
               <p class="mb-2 text-xs uppercase tracking-wider text-zinc-500">Steps</p>
@@ -555,7 +555,7 @@
 </template>
 
 <script setup lang="ts">
-type AspectId = '16:9' | '9:16' | '1:1'
+type AspectId = 'auto' | '16:9' | '9:16' | '1:1'
 
 interface LibraryFolder {
   id: string
@@ -621,13 +621,14 @@ interface RetryDraft {
   scheduler?: string
 }
 
-const PRESETS: Record<AspectId, { width: number; height: number }> = {
+const PRESETS: Record<Exclude<AspectId, 'auto'>, { width: number; height: number }> = {
   '16:9': { width: 1344, height: 768 },
   '9:16': { width: 768, height: 1344 },
   '1:1': { width: 960, height: 960 }
 }
 
 const aspects = [
+  { id: 'auto' as const, label: 'Automatic', hint: 'Match the still' },
   { id: '16:9' as const, label: '16:9 Landscape', hint: '1344 × 768' },
   { id: '9:16' as const, label: '9:16 Portrait / Shorts', hint: '768 × 1344' },
   { id: '1:1' as const, label: '1:1 Square', hint: '960 × 960' }
@@ -641,7 +642,7 @@ const dragging = ref(false)
 const prompt = ref('')
 const clipName = ref('')
 const outputDownloadName = ref('aigen')
-const aspect = ref<AspectId>('16:9')
+const aspect = ref<AspectId>('auto')
 const imageWidth = ref(0)
 const imageHeight = ref(0)
 const turbo = ref(true)
@@ -747,16 +748,44 @@ const comfyBadge = computed(() => {
   }
 })
 
-function normalizeAspect(raw?: string, width?: number, height?: number): AspectId {
-  if (raw === '16:9' || raw === '9:16' || raw === '1:1') return raw
-  if (width && height) {
-    if (width === height) return '1:1'
-    if (height > width) return '9:16'
-  }
-  return '16:9'
+function snap32(value: number) {
+  return Math.max(32, Math.round(value / 32) * 32)
 }
 
-const outputSize = computed(() => PRESETS[aspect.value])
+function autoResolution(srcWidth: number, srcHeight: number) {
+  const ratio = srcWidth / Math.max(srcHeight, 1)
+  let width: number
+  let height: number
+  if (ratio >= 1) {
+    height = 768
+    width = Math.min(1344, height * ratio)
+  } else {
+    width = 768
+    height = Math.min(1344, width / ratio)
+  }
+  width = snap32(width)
+  height = snap32(height)
+  if (width > 1344) width = 1344
+  if (height > 1344) height = 1344
+  return { width: Math.max(32, width), height: Math.max(32, height) }
+}
+
+function normalizeAspect(raw?: string): AspectId {
+  if (raw === 'auto' || raw === '16:9' || raw === '9:16' || raw === '1:1') return raw
+  return 'auto'
+}
+
+const outputSize = computed(() => {
+  if (aspect.value !== 'auto') return PRESETS[aspect.value]
+  if (imageWidth.value && imageHeight.value) return autoResolution(imageWidth.value, imageHeight.value)
+  return { width: 1344, height: 768 }
+})
+
+const autoHint = computed(() => {
+  if (!imageWidth.value || !imageHeight.value) return 'Match the still'
+  const size = autoResolution(imageWidth.value, imageHeight.value)
+  return `${size.width} × ${size.height} · from still`
+})
 const frameCount = computed(() => Math.max(5, Math.floor(duration.value * fps.value)))
 const cfgPct = computed(() => ((cfg.value - CFG_MIN) / (CFG_MAX - CFG_MIN)) * 100)
 const currentClip = computed(() => clips.value.find(clip => clip.id === currentClipId.value))
@@ -913,7 +942,7 @@ function restoreScheduler(raw?: string) {
 function restoreAdvanced(item: { turbo: boolean; aspect?: string; width?: number; height?: number; cfg?: number; fps?: number; samplerName?: string; scheduler?: string }) {
   cfgTouched.value = true
   turbo.value = item.turbo
-  aspect.value = normalizeAspect(item.aspect, item.width, item.height)
+  aspect.value = normalizeAspect(item.aspect)
   if (typeof item.cfg === 'number') {
     cfg.value = clampCfg(item.cfg)
   } else {
diff --git a/server/api/generate.post.ts b/server/api/generate.post.ts
index 1e49ccb..9813837 100644
--- a/server/api/generate.post.ts
+++ b/server/api/generate.post.ts
@@ -111,7 +111,7 @@ export default defineEventHandler(async (event) => {
     folderLocked,
     name: clipName,
     prompt,
-    aspect: fields.aspect || '16:9',
+    aspect: fields.aspect || 'auto',
     width,
     height,
     steps,
@@ -177,7 +177,7 @@ export default defineEventHandler(async (event) => {
     seed,
     width,
     height,
-    aspect: fields.aspect || '16:9',
+    aspect: fields.aspect || 'auto',
     cfg,
     fps,
     sampler_name: samplerName,
diff --git a/server/utils/resolution.ts b/server/utils/resolution.ts
index b727859..629d1ab 100644
--- a/server/utils/resolution.ts
+++ b/server/utils/resolution.ts
@@ -85,10 +85,14 @@ function jpegSize(buf: Buffer) {
   return null
 }
 
-export function resolveOutputSize(aspect: string | undefined, _image: Buffer, fallbackWidth?: number, fallbackHeight?: number) {
+export function resolveOutputSize(aspect: string | undefined, image: Buffer, fallbackWidth?: number, fallbackHeight?: number) {
   if (aspect && ASPECT_PRESETS[aspect]) {
     return ASPECT_PRESETS[aspect]
   }
+  const size = imageDimensions(image)
+  if (size?.width && size?.height) {
+    return autoResolution(size.width, size.height)
+  }
   if (Number(fallbackWidth) && Number(fallbackHeight)) {
     return { width: snap32(Number(fallbackWidth)), height: snap32(Number(fallbackHeight)) }
   }