diff --git a/app/src/main/kotlin/com/hippo/ehviewer/client/data/BaseGalleryInfo.kt b/app/src/main/kotlin/com/hippo/ehviewer/client/data/BaseGalleryInfo.kt
index 18e632cc4..67390b0d3 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/client/data/BaseGalleryInfo.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/client/data/BaseGalleryInfo.kt
@@ -23,7 +23,6 @@ import androidx.room.PrimaryKey
 import androidx.room.TypeConverter
 import androidx.room.TypeConverters
 import com.hippo.ehviewer.client.data.GalleryInfo.Companion.NOT_FAVORITED
-import kotlinx.parcelize.IgnoredOnParcel
 import kotlinx.parcelize.Parcelize
 import kotlinx.serialization.Serializable
 
@@ -91,9 +90,6 @@ data class BaseGalleryInfo(
     override var favoriteNote: String? = null,
 ) : GalleryInfo,
     Parcelable {
-    @IgnoredOnParcel
-    override val hasAds by lazy { simpleTags?.any { "extraneous ads" in it } == true }
-
     constructor() : this(0, "")
 }
 
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/client/data/GalleryInfo.kt b/app/src/main/kotlin/com/hippo/ehviewer/client/data/GalleryInfo.kt
index cde4ed643..6b9c5a854 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/client/data/GalleryInfo.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/client/data/GalleryInfo.kt
@@ -37,7 +37,6 @@ interface GalleryInfo {
     var favoriteSlot: Int
     var favoriteName: String?
     var favoriteNote: String?
-    val hasAds: Boolean
 
     fun generateSLang() {
         simpleLanguage = simpleTags?.let { generateSLangFromTags(it) }
@@ -142,3 +141,6 @@ fun GalleryInfo.findBaseInfo(): BaseGalleryInfo = when (this) {
 }
 
 fun GalleryInfo.asGalleryDetail(): GalleryDetail? = this as? GalleryDetail
+
+val GalleryInfo.hasAds
+    get() = simpleTags?.any { "extraneous ads" in it } ?: false
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/coil/Extensions.kt b/app/src/main/kotlin/com/hippo/ehviewer/coil/Extensions.kt
index 9daf43c69..d5558387a 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/coil/Extensions.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/coil/Extensions.kt
@@ -9,16 +9,12 @@ import coil3.network.NetworkHeaders
 import coil3.network.httpHeaders
 import coil3.request.CachePolicy
 import coil3.request.ImageRequest
-import coil3.request.allowHardware
 import coil3.size.Size
-import com.hippo.ehviewer.BuildConfig
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.client.CHROME_ACCEPT
 import com.hippo.ehviewer.client.CHROME_ACCEPT_LANGUAGE
-import com.hippo.ehviewer.client.data.GalleryDetail
 import com.hippo.ehviewer.client.data.GalleryInfo
 import com.hippo.ehviewer.client.data.GalleryPreview
-import com.hippo.ehviewer.client.data.LargeGalleryPreview
 import com.hippo.ehviewer.client.data.NormalGalleryPreview
 import com.hippo.ehviewer.spider.DownloadInfoMagics.encodeMagicRequestOrUrl
 import io.ktor.http.HttpHeaders
@@ -37,24 +33,11 @@ fun ImageRequest.Builder.ehUrl(info: GalleryInfo) = apply {
     httpHeaders(header)
 }
 
-context(GalleryDetail)
-fun ImageRequest.Builder.ehPreview(
-    preview: GalleryPreview,
-) = with(preview) {
+fun ImageRequest.Builder.ehPreview(preview: GalleryPreview) = with(preview) {
     data(url)
     memoryCacheKey(imageKey)
     diskCacheKey(imageKey)
-    when (preview) {
-        is NormalGalleryPreview -> size(Size.ORIGINAL)
-        is LargeGalleryPreview -> {
-            if (hasAds && detectAds(position, pages, BuildConfig.DEBUG)) {
-                size(Size.ORIGINAL)
-                detectQrCode(true)
-                allowHardware(false)
-                hardwareThreshold(0)
-            }
-        }
-    }
+    if (preview is NormalGalleryPreview) size(Size.ORIGINAL)
     httpHeaders(header)
 }
 
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/coil/QrCodeInterceptor.kt b/app/src/main/kotlin/com/hippo/ehviewer/coil/QrCodeInterceptor.kt
index c704c032d..0385e4029 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/coil/QrCodeInterceptor.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/coil/QrCodeInterceptor.kt
@@ -1,21 +1,13 @@
 package com.hippo.ehviewer.coil
 
-import androidx.collection.SieveCache
 import coil3.Extras
-import coil3.Image
 import coil3.getExtra
 import coil3.intercept.Interceptor
-import coil3.memory.MemoryCache
 import coil3.request.ImageRequest
 import coil3.request.ImageResult
 import coil3.request.SuccessResult
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.image.hasQrCode
-import eu.kanade.tachiyomi.util.system.logcat
-import java.util.concurrent.locks.ReentrantReadWriteLock
-import kotlin.concurrent.read
-import kotlin.concurrent.write
-import moe.tarsin.coroutines.runSuspendCatching
 
 private val detectQrCodeKey = Extras.Key(default = false)
 
@@ -23,9 +15,6 @@ fun ImageRequest.Builder.detectQrCode(enable: Boolean) = apply {
     extras[detectQrCodeKey] = enable
 }
 
-private val cache = SieveCache<MemoryCache.Key, Boolean>(50)
-private val lock = ReentrantReadWriteLock()
-
 val ImageRequest.detectQrCode: Boolean
     get() = getExtra(detectQrCodeKey)
 
@@ -35,11 +24,7 @@ object QrCodeInterceptor : Interceptor {
         if (chain.request.detectQrCode && result is SuccessResult) {
             val image = result.image
             if (image is BitmapImageWithExtraInfo) {
-                fun compute() = runSuspendCatching { hasQrCode(image.image.bitmap) }.onFailure { logcat(it) }.getOrThrow()
-                val hasQrCode = when (val key = result.memoryCacheKey) {
-                    is MemoryCache.Key -> lock.read { cache[key] } ?: compute().also { lock.write { cache[key] = it } }
-                    null -> compute()
-                }
+                val hasQrCode = hasQrCode(image.image.bitmap)
                 val new = image.copy(hasQrCode = hasQrCode)
                 return result.copy(image = new)
             }
@@ -48,10 +33,4 @@ object QrCodeInterceptor : Interceptor {
     }
 }
 
-val Image.hasQrCode
-    get() = when (this) {
-        is BitmapImageWithExtraInfo -> hasQrCode
-        else -> false
-    }
-
-fun detectAds(index: Int, size: Int, enable: Boolean = true) = index > size - 10 && Settings.stripExtraneousAds.value && enable
+fun detectAds(index: Int, size: Int) = index > size - 10 && Settings.stripExtraneousAds.value
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/image/Image.kt b/app/src/main/kotlin/com/hippo/ehviewer/image/Image.kt
index 1df8620b9..c39b6d5e5 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/image/Image.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/image/Image.kt
@@ -37,7 +37,6 @@ import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.coil.BitmapImageWithExtraInfo
 import com.hippo.ehviewer.coil.detectQrCode
 import com.hippo.ehviewer.coil.hardwareThreshold
-import com.hippo.ehviewer.coil.hasQrCode
 import com.hippo.ehviewer.coil.maybeCropBorder
 import com.hippo.ehviewer.jni.isGif
 import com.hippo.ehviewer.jni.mmap
@@ -56,7 +55,10 @@ import splitties.init.appCtx
 class Image private constructor(image: CoilImage, private val src: ImageSource) {
     val intrinsicSize = with(image) { IntSize(width, height) }
     val allocationSize = image.size
-    val hasQrCode = image.hasQrCode
+    val hasQrCode = when (image) {
+        is BitmapImageWithExtraInfo -> image.hasQrCode
+        else -> false
+    }
 
     var innerImage: CoilImage? = when (image) {
         is BitmapImageWithExtraInfo -> image.image
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ktbuilder/Coil.kt b/app/src/main/kotlin/com/hippo/ehviewer/ktbuilder/Coil.kt
index e8ba89747..7d534b31e 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ktbuilder/Coil.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ktbuilder/Coil.kt
@@ -5,7 +5,6 @@ import coil3.ImageLoader
 import coil3.disk.DiskCache
 import coil3.imageLoader
 import coil3.request.ImageRequest
-import com.hippo.ehviewer.client.data.GalleryDetail
 import com.hippo.ehviewer.client.data.GalleryInfo
 import com.hippo.ehviewer.client.data.GalleryPreview
 import com.hippo.ehviewer.coil.ehPreview
@@ -13,7 +12,6 @@ import com.hippo.ehviewer.coil.ehUrl
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.launch
 
-context(GalleryDetail)
 inline fun Context.imageRequest(preview: GalleryPreview, builder: ImageRequest.Builder.() -> Unit = {}) = ImageRequest.Builder(this).ehPreview(preview).apply(builder).build()
 inline fun Context.imageRequest(info: GalleryInfo, builder: ImageRequest.Builder.() -> Unit = {}) = ImageRequest.Builder(this).ehUrl(info).apply(builder).build()
 inline fun Context.imageRequest(builder: ImageRequest.Builder.() -> Unit = {}) = ImageRequest.Builder(this).apply(builder).build()
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/spider/SpiderQueen.kt b/app/src/main/kotlin/com/hippo/ehviewer/spider/SpiderQueen.kt
index 9e541cc0d..867d5d093 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/spider/SpiderQueen.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/spider/SpiderQueen.kt
@@ -26,6 +26,7 @@ import com.hippo.ehviewer.client.EhUrl.getGalleryDetailUrl
 import com.hippo.ehviewer.client.EhUrl.getGalleryMultiPageViewerUrl
 import com.hippo.ehviewer.client.EhUrl.referer
 import com.hippo.ehviewer.client.data.GalleryInfo
+import com.hippo.ehviewer.client.data.hasAds
 import com.hippo.ehviewer.client.ehRequest
 import com.hippo.ehviewer.client.exception.QuotaExceededException
 import com.hippo.ehviewer.client.fetchUsingAsText
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ui/main/GalleryPreview.kt b/app/src/main/kotlin/com/hippo/ehviewer/ui/main/GalleryPreview.kt
index 35c6c998a..5ef050587 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ui/main/GalleryPreview.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ui/main/GalleryPreview.kt
@@ -10,7 +10,6 @@ import androidx.compose.runtime.NonRestartableComposable
 import androidx.compose.runtime.getValue
 import androidx.compose.runtime.mutableStateOf
 import androidx.compose.runtime.remember
-import androidx.compose.runtime.saveable.rememberSaveable
 import androidx.compose.runtime.setValue
 import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
@@ -22,18 +21,14 @@ import androidx.compose.ui.unit.IntOffset
 import androidx.compose.ui.unit.IntSize
 import coil3.BitmapImage
 import coil3.compose.AsyncImage
-import coil3.compose.AsyncImagePainter
+import coil3.compose.AsyncImagePainter.State
 import coil3.request.ImageRequest
-import com.hippo.ehviewer.client.data.GalleryDetail
 import com.hippo.ehviewer.client.data.GalleryPreview
 import com.hippo.ehviewer.client.data.NormalGalleryPreview
-import com.hippo.ehviewer.coil.hasQrCode
 import com.hippo.ehviewer.ktbuilder.imageRequest
-import com.hippo.ehviewer.ui.reader.AdsPlaceholder
 import com.hippo.ehviewer.ui.tools.CrystalCard
 import com.hippo.ehviewer.ui.tools.shouldCrop
 
-context(GalleryDetail)
 @Composable
 @NonRestartableComposable
 fun requestOf(model: GalleryPreview): ImageRequest {
@@ -41,60 +36,48 @@ fun requestOf(model: GalleryPreview): ImageRequest {
     return remember(model) { context.imageRequest(model) }
 }
 
-context(GalleryDetail)
 @Composable
 fun EhAsyncPreview(
     model: GalleryPreview,
     modifier: Modifier = Modifier,
 ) {
     var contentScale by remember(model) { mutableStateOf(ContentScale.Fit) }
-    var blocked by rememberSaveable(model) { mutableStateOf(false) }
-    if (blocked) {
-        AdsPlaceholder(
-            modifier = modifier,
-            contentScale = ContentScale.Fit,
-        )
-    } else {
-        AsyncImage(
-            model = requestOf(model),
-            contentDescription = null,
-            modifier = modifier,
-            transform = {
+    AsyncImage(
+        model = requestOf(model),
+        contentDescription = null,
+        modifier = modifier,
+        transform = {
+            if (it is State.Success && model is NormalGalleryPreview) {
                 with(model) {
-                    when (it) {
-                        is AsyncImagePainter.State.Success if it.result.image.hasQrCode -> it.also { blocked = true }
-                        is AsyncImagePainter.State.Success if this is NormalGalleryPreview -> it.copy(
-                            painter = BitmapPainter(
-                                (it.result.image as BitmapImage).bitmap.asImageBitmap(),
-                                IntOffset(offsetX, 0),
-                                IntSize(clipWidth - 1, clipHeight - 1),
-                            ),
-                        )
-                        else -> it
+                    it.copy(
+                        painter = BitmapPainter(
+                            (it.result.image as BitmapImage).bitmap.asImageBitmap(),
+                            IntOffset(offsetX, 0),
+                            IntSize(clipWidth - 1, clipHeight - 1),
+                        ),
+                    )
+                }
+            } else {
+                it
+            }
+        },
+        onState = {
+            if (it is State.Success) {
+                if (model is NormalGalleryPreview) {
+                    if (model.shouldCrop) {
+                        contentScale = ContentScale.Crop
+                    }
+                } else {
+                    if (it.result.image.shouldCrop) {
+                        contentScale = ContentScale.Crop
                     }
                 }
-            },
-            onState = {
-                if (it is AsyncImagePainter.State.Success) {
-                    with(model) {
-                        if (this is NormalGalleryPreview) {
-                            if (shouldCrop) {
-                                contentScale = ContentScale.Crop
-                            }
-                        } else {
-                            if (it.result.image.shouldCrop) {
-                                contentScale = ContentScale.Crop
-                            }
-                        }
-                    }
-                }
-            },
-            contentScale = contentScale,
-        )
-    }
+            }
+        },
+        contentScale = contentScale,
+    )
 }
 
-context(GalleryDetail)
 @Composable
 @NonRestartableComposable
 fun EhPreviewItem(
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/ReaderScreen.kt b/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/ReaderScreen.kt
index d432db98f..6ba9880ef 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/ReaderScreen.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ui/reader/ReaderScreen.kt
@@ -57,6 +57,7 @@ import com.google.accompanist.systemuicontroller.rememberSystemUiController
 import com.hippo.ehviewer.R
 import com.hippo.ehviewer.Settings
 import com.hippo.ehviewer.client.data.BaseGalleryInfo
+import com.hippo.ehviewer.client.data.hasAds
 import com.hippo.ehviewer.collectAsState
 import com.hippo.ehviewer.download.DownloadManager
 import com.hippo.ehviewer.download.archiveFile
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailContent.kt b/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailContent.kt
index 43287a93d..2cda55430 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailContent.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailContent.kt
@@ -298,7 +298,7 @@ fun GalleryDetailContent(
                 }
             }
             if (galleryDetail != null) {
-                galleryPreview(galleryDetail, previews) { navToReader(galleryDetail.galleryInfo, it) }
+                galleryPreview(previews) { navToReader(galleryDetail.galleryInfo, it) }
             }
         }
 
@@ -366,7 +366,7 @@ fun GalleryDetailContent(
                 }
             }
             if (galleryDetail != null) {
-                galleryPreview(galleryDetail, previews) { navToReader(galleryDetail.galleryInfo, it) }
+                galleryPreview(previews) { navToReader(galleryDetail.galleryInfo, it) }
             }
         }
     }
@@ -775,19 +775,13 @@ private fun GalleryDetail?.collectPreviewItems(prefetchDistance: Int) = remember
     }.flow.cachedIn(viewModelScope)
 }.collectAsLazyPagingItems()
 
-private fun LazyGridScope.galleryPreview(
-    detail: GalleryDetail,
-    data: LazyPagingItems<GalleryPreview>,
-    onClick: (Int) -> Unit,
-) {
+private fun LazyGridScope.galleryPreview(data: LazyPagingItems<GalleryPreview>, onClick: (Int) -> Unit) {
     items(
         count = data.itemCount,
         key = data.itemKey(key = { item -> item.position }),
         contentType = { "preview" },
     ) { index ->
         val item = data[index]
-        with(detail) {
-            EhPreviewItem(item, index) { onClick(index) }
-        }
+        EhPreviewItem(item, index) { onClick(index) }
     }
 }
diff --git a/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailScreen.kt b/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailScreen.kt
index 5300d264a..5dd08711d 100644
--- a/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailScreen.kt
+++ b/app/src/main/kotlin/com/hippo/ehviewer/ui/screen/GalleryDetailScreen.kt
@@ -138,10 +138,8 @@ fun AnimatedVisibilityScope.GalleryDetailScreen(args: GalleryDetailScreenArgs, n
                     detailCache[galleryDetail.gid] = galleryDetail
                     if (Settings.preloadThumbAggressively) {
                         launchIO {
-                            with(galleryDetail) {
-                                previewList.forEach {
-                                    imageLoader.enqueue(imageRequest(it) { justDownload() })
-                                }
+                            galleryDetail.previewList.forEach {
+                                imageLoader.enqueue(imageRequest(it) { justDownload() })
                             }
                         }
                     }