diff --git a/app/src/main/java/com/droiddeck/launcher/stores/StoreSizes.kt b/app/src/main/java/com/droiddeck/launcher/stores/StoreSizes.kt
new file mode 100644
index 000000000..e2cf47489
--- /dev/null
+++ b/app/src/main/java/com/droiddeck/launcher/stores/StoreSizes.kt
@@ -0,0 +1,74 @@
+package com.droiddeck.launcher.stores
+
+import android.content.Context
+import android.util.Log
+import androidx.compose.runtime.mutableStateMapOf
+import com.droiddeck.launcher.stores.amazon.AmazonApiClient
+import com.droiddeck.launcher.stores.amazon.AmazonCredentialStore
+import com.droiddeck.launcher.stores.amazon.AmazonManifest
+import com.droiddeck.launcher.stores.amazon.AmazonPrefs
+import com.droiddeck.launcher.stores.epic.EpicApiClient
+import com.droiddeck.launcher.stores.epic.EpicCredentialStore
+import com.droiddeck.launcher.stores.epic.EpicDownloadManager
+import com.droiddeck.launcher.stores.epic.EpicInstallTags
+import com.droiddeck.launcher.stores.epic.EpicPrefs
+import java.util.concurrent.ConcurrentHashMap
+import java.util.concurrent.Executors
+
+/**
+ * Install sizes for owned Epic and Amazon games, whose library answers carry none: Epic's from the
+ * game's build manifest (the files this device installs), Amazon's from its download manifest.
+ * Asked for a card as it comes on screen, three at a time in the background, once per game - the
+ * answer is kept in the store's prefs (`size_<id>`, where the library reads it too). Until it is
+ * known the card shows nothing.
+ */
+object StoreSizes {
+    private const val TAG = "StoreSizes"
+
+    /** Sizes found this run, by card key; the cards read them. */
+    val known = mutableStateMapOf<String, Long>()
+
+    private val asked = ConcurrentHashMap.newKeySet<String>()
+    private val pool = Executors.newFixedThreadPool(3, com.droiddeck.launcher.stores.download.DownloadQueue.workerFactory("sizes"))
+
+    fun size(item: CatalogItem): Long = known[item.key] ?: item.sizeBytes
+
+    /** A card for [item] is on screen (or about to be): find its size if nothing has yet. */
+    fun request(context: Context, item: CatalogItem) {
+        if (!item.owned || item.sizeBytes > 0 || item.store == Store.GOG) return
+        if (known.containsKey(item.key) || !asked.add(item.key)) return
+        val app = context.applicationContext
+        pool.execute {
+            val bytes = runCatching { fetch(app, item) }.onFailure { Log.w(TAG, "${item.key}: ${it.javaClass.simpleName}") }.getOrNull() ?: 0L
+            if (bytes > 0) {
+                when (item.store) {
+                    Store.EPIC -> EpicPrefs.get(app).edit().putLong("size_${item.id}", bytes).apply()
+                    Store.AMAZON -> AmazonPrefs.get(app).edit().putLong("size_${item.id}", bytes).apply()
+                    Store.GOG -> {}
+                }
+                StoresState.post { known[item.key] = bytes }
+            }
+        }
+    }
+
+    private fun fetch(context: Context, item: CatalogItem): Long = when (item.store) {
+        Store.EPIC -> {
+            val token = EpicCredentialStore.getValidAccessToken(context) ?: return 0L
+            val ns = item.extra["namespace"].orEmpty()
+            val catalogItemId = item.extra["catalogItemId"].orEmpty()
+            if (ns.isEmpty() || catalogItemId.isEmpty()) return 0L
+            val json = EpicApiClient.getManifestApiJson(token, ns, catalogItemId, item.id) ?: return 0L
+            val bytes = EpicDownloadManager.downloadManifest(json, EpicDownloadManager.parseCdnUrls(json)) ?: return 0L
+            val manifest = EpicDownloadManager.parseManifest(bytes) ?: return 0L
+            EpicDownloadManager.resolveInstallFiles(manifest, EpicInstallTags.tagsForDevice()).sumOf { it.fileSize() }
+        }
+        Store.AMAZON -> {
+            val token = AmazonCredentialStore.getValidAccessToken(context) ?: return 0L
+            val entitlement = item.extra["entitlementId"].orEmpty().ifEmpty { return 0L }
+            val spec = AmazonApiClient.getGameDownload(token, entitlement) ?: return 0L
+            val bytes = AmazonApiClient.getBytes(AmazonApiClient.appendPath(spec.downloadUrl, "manifest.proto"), token) ?: return 0L
+            AmazonManifest.parse(bytes).totalInstallSize
+        }
+        Store.GOG -> 0L
+    }
+}
diff --git a/app/src/main/java/com/droiddeck/launcher/ui/StoresPage.kt b/app/src/main/java/com/droiddeck/launcher/ui/StoresPage.kt
index 78af32e3e..7a554ff67 100644
--- a/app/src/main/java/com/droiddeck/launcher/ui/StoresPage.kt
+++ b/app/src/main/java/com/droiddeck/launcher/ui/StoresPage.kt
@@ -1,5 +1,7 @@
 package com.droiddeck.launcher.ui
 
+import androidx.compose.ui.layout.boundsInWindow
+import androidx.compose.ui.layout.onGloballyPositioned
 import androidx.compose.ui.layout.onSizeChanged
 import androidx.compose.ui.draw.drawWithContent
 import androidx.compose.ui.draw.drawBehind
@@ -492,8 +494,18 @@ private fun GameCard(item: CatalogItem, store: Store, s: FrontEndState, a: Front
     val installed = item.id in installedKeys
     val download = StoresState.download("${store.id}:${item.id}")?.takeIf { it.isActive }
     val open = { onOpen(item.key) }
+    // A size the library did not give is looked up once the card is on screen or close to it.
+    val screen = with(androidx.compose.ui.platform.LocalDensity.current) { androidx.compose.ui.platform.LocalConfiguration.current.screenHeightDp.dp.toPx() }
+    val ahead = screen / 2
     Column(
-        modifier = Modifier.fillMaxWidth().paneItem("card:${item.key}").then(if (first) Modifier.firstTile() else Modifier).graphicsLayer { scaleX = scale; scaleY = scale }
+        modifier = Modifier.fillMaxWidth()
+            .onGloballyPositioned { c ->
+                if (item.owned && item.sizeBytes <= 0) {
+                    val b = c.boundsInWindow()
+                    if (b.bottom > -ahead && b.top < screen + ahead && b.width > 0f) com.droiddeck.launcher.stores.StoreSizes.request(ctx, item)
+                }
+            }
+            .paneItem("card:${item.key}").then(if (first) Modifier.firstTile() else Modifier).graphicsLayer { scaleX = scale; scaleY = scale }
             .clip(RoundedCornerShape(10.dp)).glideBorder(hot, RoundedCornerShape(10.dp), pal.signal, pal.line)
             .hoverable(src).clickable(interactionSource = src, indication = LocalIndication.current, onClick = open).controllerConfirm(onClick = open),
     ) {
@@ -565,7 +577,8 @@ private fun CardMarker(item: CatalogItem, installed: Boolean, download: com.droi
         installed -> Icon(Icons.Filled.Check, stringResource(R.string.stores_installed_chip), tint = pal.good, modifier = Modifier.size(14.dp))
         download != null -> Text("${download.percent}%", fontSize = small, fontWeight = FontWeight.Bold, color = pal.signal, maxLines = 1)
         item.owned && StoresState.isUnfinished(item) -> Text(stringResource(R.string.stores_resume), fontSize = small, fontWeight = FontWeight.Bold, color = pal.signal, maxLines = 1)
-        item.owned -> if (item.sizeBytes > 0) Text(formatBytes(item.sizeBytes), fontSize = small, color = Color.White.copy(alpha = 0.8f), maxLines = 1)
+        // The size in the title's own type; nothing until it is known.
+        item.owned -> com.droiddeck.launcher.stores.StoreSizes.size(item).takeIf { it > 0 }?.let { Text(formatBytes(it), fontSize = 11.sp, fontWeight = FontWeight.Bold, color = Color.White, maxLines = 1) }
         item.isFree -> Text(stringResource(R.string.stores_free), fontSize = small, fontWeight = FontWeight.Bold, color = pal.good, maxLines = 1)
         item.isDiscounted -> Row(verticalAlignment = Alignment.CenterVertically, horizontalArrangement = Arrangement.spacedBy(4.dp)) {
             StateChip("-${item.discountPercent}%", ChipTone.DEAL, small = true)
diff --git a/docs/progress-log.md b/docs/progress-log.md
index 49a7a4782..e585a3814 100644
--- a/docs/progress-log.md
+++ b/docs/progress-log.md
@@ -153,6 +153,11 @@ without it and Setup says "Stores engine not built").
 - **Cloud saves device-proven (AYANEO Pocket FIT, `6a175f1`, ELDERBORN on GOG):** the launch logged
   `cloud gog 1732383191 down result=ok files=5 bytes=237499 reason=downloaded` (template found) and
   the in-game slot shows the cloud save (Catacombs: Tutorial part 1, 00:08:40).
+- **Every owned card shows its size** at the right of its title strip, in the title's type: GOG's from
+  its catalog; Epic's (build manifest, the files this device installs) and Amazon's (download
+  manifest) looked up once a card is on screen or close, three at a time in the background, kept in
+  the store's prefs (`size_<id>`). Nothing shows until it is known; a marker (installed, Resume, a
+  download's percent) keeps the slot.
 - **Two tabs, Store and Library** (the All count mixed owned games with whatever shelves had loaded:
   GOG Library 33 / All 120): Library's dropdown filters All (every owned game, the default, the
   tab's count) or Installed, and the tab reads the filter ("Library (33)", "Installed (1)"); the old