diff --git a/docs/backend/upgrades.md b/docs/backend/upgrades.md
index ef6595bb..330a3e51 100644
--- a/docs/backend/upgrades.md
+++ b/docs/backend/upgrades.md
@@ -16,6 +16,7 @@ letting Arr's own upgrade logic decide whether to grab them.
 - [Filters](#filters)
 - [Dynamic Filter Values](#dynamic-filter-values)
 - [Selectors](#selectors)
+- [Filter Preview](#filter-preview)
 - [Scheduling](#scheduling)
 - [Cooldown](#cooldown)
 - [Dry Run](#dry-run)
@@ -152,6 +153,24 @@ specifies a selector strategy and a count (items per run).
 
 Selector definitions live in `src/lib/shared/upgrades/selectors.ts`.
 
+## Filter Preview
+
+The upgrades page can preview a single filter without running a dry run. The
+preview fetches the current Arr library, quality profiles, file metadata where
+needed, and tags, then applies the same normalization, filter evaluation,
+cooldown tag check, and selector ordering used by the upgrade processor.
+
+Preview is read-only. It does not search indexers, does not use the dry-run
+cooldown, and does not apply or reset cooldown tags. Results are grouped as
+selected, selectable, cooldown, and filtered out so users can inspect the
+filtered pool before triggering a real run.
+
+Preview library data is cached in memory for 5 minutes per Arr instance. An
+expired entry is treated as a cache miss: preview fetches fresh library data
+from Arr and replaces the cached entry. This keeps repeated filter edits fast
+while limiting stale preview data to a short window. Real upgrade runs do not
+use this preview cache.
+
 ## Scheduling
 
 Each Arr instance has a single upgrade config with a global cron schedule.
diff --git a/src/lib/client/ui/table/ExpandableTable.svelte b/src/lib/client/ui/table/ExpandableTable.svelte
index 92f17d40..6c5a685f 100644
--- a/src/lib/client/ui/table/ExpandableTable.svelte
+++ b/src/lib/client/ui/table/ExpandableTable.svelte
@@ -21,10 +21,12 @@
 	export let onRowClick: ((row: T) => void) | null = null;
 	export let primaryColumnKey: string | null = null;
 	export let disableExpandWhen: ((row: T) => boolean) | null = null;
+	export let rowClass: ((row: T) => string) | null = null;
 	// Mobile responsive mode - switches to card layout on small screens
 	export let responsive: boolean = false;
 	// Progressive loading - render items in batches as user scrolls
 	export let pageSize: number | undefined = undefined;
+	export let fixedLayout: boolean = false;
 
 	let isMobile = false;
 	let mediaQuery: MediaQueryList | null = null;
@@ -200,7 +202,9 @@
 			{#each displayData as row, index}
 				{@const rowId = getRowId(row)}
 				<div
-					class="overflow-hidden rounded-xl border border-neutral-300 bg-white dark:border-neutral-700/60 dark:bg-neutral-800/50"
+					class="overflow-hidden rounded-xl border border-neutral-300 bg-white dark:border-neutral-700/60 dark:bg-neutral-800/50 {rowClass
+						? rowClass(row)
+						: ''}"
 				>
 					<!-- Card Header - clickable to expand -->
 					<!-- svelte-ignore a11y-click-events-have-key-events a11y-no-static-element-interactions -->
@@ -305,14 +309,14 @@
 			? 'rounded-b-none border-b-0'
 			: ''}"
 	>
-		<table class="w-full">
+		<table class="w-full {fixedLayout ? 'table-fixed' : ''}">
 			<thead
 				class="border-b border-neutral-300 bg-neutral-50 dark:border-neutral-700/60 dark:bg-neutral-800/50"
 			>
 				<tr>
 					<!-- Expand column (left) -->
 					{#if chevronPosition === 'left'}
-						<th class="{compact ? 'px-2 py-2.5' : 'px-3 py-3'} w-8"></th>
+						<th class="{compact ? 'px-3 py-2.5' : 'px-4 py-3'} w-12"></th>
 					{/if}
 					{#each columns as column}
 						<th
@@ -358,7 +362,7 @@
 					{/if}
 					<!-- Expand column (right) -->
 					{#if chevronPosition === 'right'}
-						<th class="{compact ? 'px-2 py-2.5' : 'px-3 py-3'} w-8"></th>
+						<th class="{compact ? 'px-3 py-2.5' : 'px-4 py-3'} w-12"></th>
 					{/if}
 				</tr>
 			</thead>
@@ -412,12 +416,14 @@
 
 						<!-- Main Row -->
 						<tr
-							class="cursor-pointer transition-colors hover:bg-neutral-50 dark:hover:bg-neutral-800"
+							class="cursor-pointer transition-colors hover:bg-neutral-50 dark:hover:bg-neutral-800 {rowClass
+								? rowClass(row)
+								: ''}"
 							on:click={() => handleRowClick(rowId, row)}
 						>
 							<!-- Expand Icon (left) -->
 							{#if chevronPosition === 'left'}
-								<td class="{compact ? 'px-2 py-2' : 'px-3 py-3'} text-neutral-400">
+								<td class="{compact ? 'px-3 py-2' : 'px-4 py-3'} text-neutral-400">
 									{#if !shouldDisableExpand(row)}
 										<Button
 											icon={expandedRows.has(rowId) ? ChevronUp : ChevronDown}
@@ -456,7 +462,7 @@
 
 							<!-- Expand Icon (right) -->
 							{#if chevronPosition === 'right'}
-								<td class="{compact ? 'px-2 py-2' : 'px-3 py-3'} text-right text-neutral-400">
+								<td class="{compact ? 'px-3 py-2' : 'px-4 py-3'} text-right text-neutral-400">
 									{#if !shouldDisableExpand(row)}
 										<Button
 											icon={expandedRows.has(rowId) ? ChevronUp : ChevronDown}
diff --git a/src/lib/server/upgrades/normalize.ts b/src/lib/server/upgrades/normalize.ts
index 9f8cbd57..727e0992 100644
--- a/src/lib/server/upgrades/normalize.ts
+++ b/src/lib/server/upgrades/normalize.ts
@@ -7,10 +7,31 @@ import type {
 	RadarrMovie,
 	RadarrMovieFile,
 	SonarrSeries,
-	ArrQualityProfile
+	ArrQualityProfile,
+	CustomFormatRef,
+	QualityProfileFormatItem,
+	ScoreBreakdownItem
 } from '$lib/server/utils/arr/types.ts';
 import type { UpgradeItem } from './types.ts';
 
+function getFileName(path: string | undefined): string {
+	if (!path) return '';
+	return path.split('/').pop() ?? path;
+}
+
+function computeScoreBreakdown(
+	customFormats: CustomFormatRef[],
+	profileFormatItems: QualityProfileFormatItem[]
+): ScoreBreakdownItem[] {
+	return customFormats.map((format) => {
+		const profileItem = profileFormatItems.find((item) => item.format === format.id);
+		return {
+			name: format.name,
+			score: profileItem?.score ?? 0
+		};
+	});
+}
+
 /**
  * Normalize a Radarr movie to an UpgradeItem for filter evaluation
  *
@@ -67,14 +88,20 @@ export function normalizeRadarrItem(
 		monitored: movie.monitored ?? false,
 		cutoff_met: cutoffMet,
 		quality_profile: profile?.name ?? 'Unknown',
+		quality_name: movieFile?.quality?.quality?.name ?? '',
+		file_name: getFileName(movieFile?.relativePath ?? movieFile?.path),
 		original_language: movie.originalLanguage?.name ?? '',
 		genres: movie.genres?.join(', ') ?? '',
 		tags,
 		custom_formats: movieFile?.customFormats.map((cf) => cf.name) ?? [],
+		score_breakdown: movieFile
+			? computeScoreBreakdown(movieFile.customFormats, profile?.formatItems ?? [])
+			: [],
 		rating: tmdbRating,
 		runtime: movie.runtime ?? 0,
 		size_on_disk: sizeOnDiskGB,
 		date_added: dateAdded,
+		path: movie.path ?? '',
 
 		// Radarr-specific fields
 		minimum_availability: movie.minimumAvailability ?? 'released',
@@ -168,14 +195,18 @@ export function normalizeSonarrItem(
 		monitored: series.monitored,
 		cutoff_met: cutoffMet,
 		quality_profile: profile?.name ?? 'Unknown',
+		quality_name: '',
+		file_name: '',
 		original_language: series.originalLanguage?.name ?? '',
 		genres: series.genres?.join(', ') ?? '',
 		tags,
 		custom_formats: [],
+		score_breakdown: [],
 		rating: series.ratings?.value ?? 0,
 		runtime: series.runtime ?? 0,
 		size_on_disk: sizeOnDiskGB,
 		date_added: dateAdded,
+		path: series.path ?? '',
 
 		// Radarr fields (defaults for Sonarr)
 		minimum_availability: '',
diff --git a/src/lib/server/upgrades/preview.ts b/src/lib/server/upgrades/preview.ts
new file mode 100644
index 00000000..526ce019
--- /dev/null
+++ b/src/lib/server/upgrades/preview.ts
@@ -0,0 +1,419 @@
+import type { ArrInstance } from '$db/queries/arrInstances.ts';
+import { RadarrClient } from '$utils/arr/clients/radarr.ts';
+import { SonarrClient } from '$utils/arr/clients/sonarr.ts';
+import type {
+	ArrQualityProfile,
+	ArrTag,
+	RadarrMovie,
+	RadarrMovieFile,
+	SonarrSeries
+} from '$utils/arr/types.ts';
+import {
+	evaluateGroup,
+	evaluateRule,
+	getFilterField,
+	isGroup,
+	isRule,
+	type FilterConfig,
+	type FilterField,
+	type FilterGroup,
+	type FilterRule,
+	type UpgradeAppType
+} from '$shared/upgrades/filters.ts';
+import { getSelector } from '$shared/upgrades/selectors.ts';
+import { hasFilterTag, resolveTagLabel } from './cooldown.ts';
+import { normalizeRadarrItems, normalizeSonarrItems } from './normalize.ts';
+import type { UpgradeItem } from './types.ts';
+
+export type UpgradeFilterPreviewStatus = 'selected' | 'selectable' | 'cooldown' | 'filtered_out';
+
+export interface UpgradeFilterPreviewFormat {
+	name: string;
+	score: number;
+}
+
+export interface UpgradeFilterPreviewDetails {
+	qualityProfile: string;
+	fileName: string;
+	customFormats: UpgradeFilterPreviewFormat[];
+	score: number;
+	tags: string[];
+	monitored: boolean;
+	dateAdded: string;
+	sizeOnDisk: number;
+	releaseGroup: string;
+	status: string;
+}
+
+export interface UpgradeFilterPreviewItem {
+	id: number;
+	title: string;
+	year: number;
+	status: UpgradeFilterPreviewStatus;
+	reason: string;
+	details: UpgradeFilterPreviewDetails;
+}
+
+export interface UpgradeFilterPreviewResult {
+	filterName: string;
+	totalItems: number;
+	matchedCount: number;
+	cooldownCount: number;
+	selectableCount: number;
+	selectedCount: number;
+	requestedCount: number;
+	selector: string;
+	items: UpgradeFilterPreviewItem[];
+}
+
+interface RadarrPreviewCacheEntry {
+	expiresAt: number;
+	movies: RadarrMovie[];
+	profiles: ArrQualityProfile[];
+	movieFiles: RadarrMovieFile[];
+	tags: ArrTag[];
+}
+
+interface SonarrPreviewCacheEntry {
+	expiresAt: number;
+	series: SonarrSeries[];
+	profiles: ArrQualityProfile[];
+	tags: ArrTag[];
+}
+
+interface PreviewLoadResult {
+	items: UpgradeItem[];
+	tags: ArrTag[];
+}
+
+const PREVIEW_CACHE_TTL_MS = 5 * 60 * 1000;
+const radarrPreviewCache = new Map<number, RadarrPreviewCacheEntry>();
+const sonarrPreviewCache = new Map<number, SonarrPreviewCacheEntry>();
+
+function toPreviewItem(
+	item: UpgradeItem,
+	status: UpgradeFilterPreviewStatus,
+	reason: string
+): UpgradeFilterPreviewItem {
+	return {
+		id: item.id,
+		title: item.title,
+		year: item.year,
+		status,
+		reason,
+		details: {
+			qualityProfile: item.quality_profile,
+			fileName: item.file_name,
+			customFormats: item.score_breakdown,
+			score: item.score,
+			tags: item.tags
+				.split(',')
+				.map((tag) => tag.trim())
+				.filter(Boolean),
+			monitored: item.monitored,
+			dateAdded: item.date_added,
+			sizeOnDisk: item.size_on_disk,
+			releaseGroup: item.release_group,
+			status: item.status
+		}
+	};
+}
+
+function formatValue(value: unknown, field?: FilterField): string {
+	if (value === null || value === undefined || value === '') {
+		return 'empty';
+	}
+
+	const matchingValue = field?.values?.find((option) => Object.is(option.value, value));
+	if (matchingValue) {
+		return matchingValue.label;
+	}
+
+	if (Array.isArray(value)) {
+		return value.length > 0 ? value.join(', ') : 'none';
+	}
+
+	if (typeof value === 'boolean') {
+		return value ? 'True' : 'False';
+	}
+
+	return String(value);
+}
+
+function pluralize(count: number, singular: string, plural = `${singular}s`): string {
+	return `${count} ${count === 1 ? singular : plural}`;
+}
+
+function formatFailedRule(item: UpgradeItem, rule: FilterRule, appType: UpgradeAppType): string {
+	const field = getFilterField(rule.field, appType);
+	const fieldLabel = field?.label ?? rule.field;
+	const actualValue =
+		rule.field === 'custom_format'
+			? item.custom_formats
+			: (item as unknown as Record<string, unknown>)[rule.field];
+	const expectedValue = formatValue(rule.value, field);
+	const actualLabel = formatValue(actualValue, field);
+
+	switch (rule.operator) {
+		case 'is':
+		case 'eq':
+			return `${fieldLabel} is ${actualLabel}, not ${expectedValue}`;
+		case 'is_not':
+		case 'neq':
+			return `${fieldLabel} is ${expectedValue}`;
+		case 'contains':
+		case 'includes':
+			return `${fieldLabel} does not contain ${expectedValue}`;
+		case 'not_contains':
+		case 'does_not_include':
+			return `${fieldLabel} contains ${expectedValue}`;
+		case 'starts_with':
+			return `${fieldLabel} does not start with ${expectedValue}`;
+		case 'ends_with':
+			return `${fieldLabel} does not end with ${expectedValue}`;
+		case 'is_only':
+			return `${fieldLabel} is not only ${expectedValue}`;
+		case 'has_any':
+			return `${fieldLabel} has none`;
+		case 'has_none':
+			return `${fieldLabel} has values`;
+		case 'gte':
+			return field?.valueType === 'number'
+				? `${fieldLabel} is below ${expectedValue}`
+				: `${fieldLabel} has not reached ${expectedValue}`;
+		case 'lte':
+			return field?.valueType === 'number'
+				? `${fieldLabel} is above ${expectedValue}`
+				: `${fieldLabel} has passed ${expectedValue}`;
+		case 'gt':
+			return `${fieldLabel} is not above ${expectedValue}`;
+		case 'lt':
+			return `${fieldLabel} is not below ${expectedValue}`;
+		case 'before':
+			return `${fieldLabel} is not before ${expectedValue}`;
+		case 'after':
+			return `${fieldLabel} is not after ${expectedValue}`;
+		case 'in_last':
+			return `${fieldLabel} is not in the last ${expectedValue} days`;
+		case 'not_in_last':
+			return `${fieldLabel} is in the last ${expectedValue} days`;
+		default:
+			return `${fieldLabel} did not match`;
+	}
+}
+
+function explainGroupMismatch(
+	item: UpgradeItem,
+	group: FilterGroup,
+	appType: UpgradeAppType
+): string {
+	const record = item as unknown as Record<string, unknown>;
+
+	if (group.match === 'all') {
+		for (const child of group.children) {
+			if (isRule(child) && !evaluateRule(record, child)) {
+				return formatFailedRule(item, child, appType);
+			}
+
+			if (isGroup(child) && !evaluateGroup(record, child)) {
+				return explainGroupMismatch(item, child, appType);
+			}
+		}
+	}
+
+	if (group.match === 'any' && group.children.length > 0) {
+		for (const child of group.children) {
+			if (isRule(child) && !evaluateRule(record, child)) {
+				return `No option matched: ${formatFailedRule(item, child, appType)}`;
+			}
+
+			if (isGroup(child) && !evaluateGroup(record, child)) {
+				return `No option matched: ${explainGroupMismatch(item, child, appType)}`;
+			}
+		}
+	}
+
+	return 'Filter rules did not match';
+}
+
+async function loadRadarrItems(
+	instanceId: number,
+	client: RadarrClient,
+	filter: FilterConfig
+): Promise<PreviewLoadResult> {
+	const cached = radarrPreviewCache.get(instanceId);
+	const now = Date.now();
+	let movies: RadarrMovie[];
+	let profiles: ArrQualityProfile[];
+	let movieFiles: RadarrMovieFile[];
+	let tags: ArrTag[];
+
+	if (cached && cached.expiresAt > now) {
+		movies = cached.movies;
+		profiles = cached.profiles;
+		movieFiles = cached.movieFiles;
+		tags = cached.tags;
+	} else {
+		const [loadedMovies, loadedProfiles] = await Promise.all([
+			client.getMovies(),
+			client.getQualityProfiles()
+		]);
+		const movieIdsWithFiles = loadedMovies
+			.filter((movie) => movie.hasFile)
+			.map((movie) => movie.id);
+		const loadedMovieFiles = await client.getMovieFiles(movieIdsWithFiles);
+		const loadedTags = await client.getTags();
+
+		movies = loadedMovies;
+		profiles = loadedProfiles;
+		movieFiles = loadedMovieFiles;
+		tags = loadedTags;
+
+		radarrPreviewCache.set(instanceId, {
+			expiresAt: Date.now() + PREVIEW_CACHE_TTL_MS,
+			movies,
+			profiles,
+			movieFiles,
+			tags
+		});
+	}
+
+	const movieFileMap = new Map<number, RadarrMovieFile>(
+		movieFiles.map((movieFile) => [movieFile.movieId, movieFile])
+	);
+	const profileMap = new Map(profiles.map((profile) => [profile.id, profile]));
+	const tagMap = new Map(tags.map((tag) => [tag.id, tag.label]));
+	const items = normalizeRadarrItems(movies, movieFileMap, profileMap, filter.cutoff, tagMap);
+
+	return {
+		items,
+		tags
+	};
+}
+
+async function loadSonarrItems(
+	instanceId: number,
+	client: SonarrClient,
+	filter: FilterConfig
+): Promise<PreviewLoadResult> {
+	const cached = sonarrPreviewCache.get(instanceId);
+	const now = Date.now();
+	let series: SonarrSeries[];
+	let profiles: ArrQualityProfile[];
+	let tags: ArrTag[];
+
+	if (cached && cached.expiresAt > now) {
+		series = cached.series;
+		profiles = cached.profiles;
+		tags = cached.tags;
+	} else {
+		const [loadedSeries, loadedProfiles] = await Promise.all([
+			client.getAllSeries(),
+			client.getQualityProfiles()
+		]);
+		const loadedTags = await client.getTags();
+
+		series = loadedSeries;
+		profiles = loadedProfiles;
+		tags = loadedTags;
+
+		sonarrPreviewCache.set(instanceId, {
+			expiresAt: Date.now() + PREVIEW_CACHE_TTL_MS,
+			series,
+			profiles,
+			tags
+		});
+	}
+
+	const profileMap = new Map(profiles.map((profile) => [profile.id, profile]));
+	const tagMap = new Map(tags.map((tag) => [tag.id, tag.label]));
+	const items = normalizeSonarrItems(series, profileMap, filter.cutoff, tagMap);
+
+	return {
+		items,
+		tags
+	};
+}
+
+function buildPreview(
+	filter: FilterConfig,
+	normalizedItems: UpgradeItem[],
+	tags: ArrTag[],
+	appType: UpgradeAppType
+): UpgradeFilterPreviewResult {
+	const matchedItems = normalizedItems.filter((item) =>
+		evaluateGroup(item as unknown as Record<string, unknown>, filter.group)
+	);
+	const matchedIds = new Set(matchedItems.map((item) => item.id));
+
+	const tagLabel = resolveTagLabel(filter);
+	const cooldownItems = matchedItems.filter((item) => hasFilterTag(item._tags, tags, tagLabel));
+	const cooldownIds = new Set(cooldownItems.map((item) => item.id));
+	const selectableItems = matchedItems.filter((item) => !cooldownIds.has(item.id));
+
+	const selector = getSelector(filter.selector);
+	const orderedSelectableItems = selector
+		? selector.select(selectableItems, selectableItems.length)
+		: selectableItems;
+	const selectedItems = orderedSelectableItems.slice(0, Math.max(0, filter.count));
+	const selectedIds = new Set(selectedItems.map((item) => item.id));
+	const remainingSelectableItems = orderedSelectableItems.filter(
+		(item) => !selectedIds.has(item.id)
+	);
+
+	const filteredOutItems = normalizedItems.filter((item) => !matchedIds.has(item.id));
+	const selectorLabel = selector?.label ?? filter.selector;
+	const cooldownRemaining = pluralize(selectableItems.length, 'item');
+	const cooldownReason =
+		selectableItems.length > 0
+			? `Already searched by this filter. ${cooldownRemaining} still eligible before the cooldown resets.`
+			: 'Already searched by this filter. Cooldown will reset on the next run.';
+
+	return {
+		filterName: filter.name,
+		totalItems: normalizedItems.length,
+		matchedCount: matchedItems.length,
+		cooldownCount: cooldownItems.length,
+		selectableCount: selectableItems.length,
+		selectedCount: selectedItems.length,
+		requestedCount: filter.count,
+		selector: filter.selector,
+		items: [
+			...selectedItems.map((item) =>
+				toPreviewItem(item, 'selected', `Will search next using ${selectorLabel}`)
+			),
+			...remainingSelectableItems.map((item) =>
+				toPreviewItem(item, 'selectable', 'Matches this filter and is waiting for a later run')
+			),
+			...cooldownItems.map((item) => toPreviewItem(item, 'cooldown', cooldownReason)),
+			...filteredOutItems.map((item) =>
+				toPreviewItem(item, 'filtered_out', explainGroupMismatch(item, filter.group, appType))
+			)
+		]
+	};
+}
+
+export async function previewUpgradeFilter(
+	instance: ArrInstance,
+	filter: FilterConfig
+): Promise<UpgradeFilterPreviewResult> {
+	if (instance.type !== 'radarr' && instance.type !== 'sonarr') {
+		throw new Error(`Upgrade preview is not supported for ${instance.type}`);
+	}
+
+	const appType = instance.type as UpgradeAppType;
+	const client =
+		instance.type === 'radarr'
+			? new RadarrClient(instance.url, instance.api_key, { timeout: 120000 })
+			: new SonarrClient(instance.url, instance.api_key, { timeout: 120000 });
+
+	try {
+		const { items, tags } =
+			instance.type === 'radarr'
+				? await loadRadarrItems(instance.id, client as RadarrClient, filter)
+				: await loadSonarrItems(instance.id, client as SonarrClient, filter);
+		return buildPreview(filter, items, tags, appType);
+	} finally {
+		client.close();
+	}
+}
diff --git a/src/lib/server/upgrades/types.ts b/src/lib/server/upgrades/types.ts
index 8b93f9de..cc741eee 100644
--- a/src/lib/server/upgrades/types.ts
+++ b/src/lib/server/upgrades/types.ts
@@ -2,7 +2,7 @@
  * Types for the upgrade processing system
  */
 
-import type { RadarrMovie, SonarrSeries } from '$lib/server/utils/arr/types.ts';
+import type { RadarrMovie, ScoreBreakdownItem, SonarrSeries } from '$lib/server/utils/arr/types.ts';
 import type { FilterGroup } from '$shared/upgrades/filters.ts';
 
 /**
@@ -17,14 +17,18 @@ export interface UpgradeItem {
 	monitored: boolean;
 	cutoff_met: boolean;
 	quality_profile: string;
+	quality_name: string;
+	file_name: string;
 	original_language: string;
 	genres: string;
 	tags: string;
 	custom_formats: string[];
+	score_breakdown: ScoreBreakdownItem[];
 	rating: number;
 	runtime: number;
 	size_on_disk: number;
 	date_added: string;
+	path: string;
 
 	// Radarr-only fields (empty/zero defaults for Sonarr)
 	minimum_availability: string;
@@ -92,7 +96,7 @@ export interface UpgradeNewRelease {
 	release: string; // release title
 	formats: string[];
 	score: number;
-	seasonNumber?: number; // Sonarr only — which season this grab is for
+	seasonNumber?: number; // Sonarr only, which season this grab is for
 }
 
 /**
diff --git a/src/routes/arr/[id]/upgrades/components/FilterPreviewModal.svelte b/src/routes/arr/[id]/upgrades/components/FilterPreviewModal.svelte
new file mode 100644
index 00000000..5f99b7d6
--- /dev/null
+++ b/src/routes/arr/[id]/upgrades/components/FilterPreviewModal.svelte
@@ -0,0 +1,581 @@
+<script lang="ts">
+	import { createEventDispatcher, onDestroy } from 'svelte';
+	import { CircleDot, Loader2 } from 'lucide-svelte';
+	import type { FilterConfig } from '$shared/upgrades/filters';
+	import { selectors } from '$shared/upgrades/selectors';
+	import { createSearchStore, type SearchStore } from '$lib/client/stores/search';
+	import { serverTimezone } from '$lib/client/stores/timezone';
+	import { formatDate } from '$shared/utils/dates';
+	import type { Readable } from 'svelte/store';
+	import ActionsBar from '$ui/actions/ActionsBar.svelte';
+	import ActionButton from '$ui/actions/ActionButton.svelte';
+	import SearchAction from '$ui/actions/SearchAction.svelte';
+	import Dropdown from '$ui/dropdown/Dropdown.svelte';
+	import DropdownHeader from '$ui/dropdown/DropdownHeader.svelte';
+	import DropdownItem from '$ui/dropdown/DropdownItem.svelte';
+	import Button from '$ui/button/Button.svelte';
+	import Modal from '$ui/modal/Modal.svelte';
+	import Label from '$ui/label/Label.svelte';
+	import CustomFormatBadge from '$ui/arr/CustomFormatBadge.svelte';
+	import ExpandableTable from '$ui/table/ExpandableTable.svelte';
+	import type { Column } from '$ui/table/types';
+
+	export let open = false;
+	export let filter: FilterConfig | null = null;
+	export let instanceId: string | undefined = undefined;
+
+	type PreviewStatus = 'selected' | 'selectable' | 'cooldown' | 'filtered_out';
+	type PreviewLabelVariant = 'secondary' | 'success' | 'warning' | 'info';
+
+	interface PreviewItem {
+		id: number;
+		title: string;
+		year: number;
+		status: PreviewStatus;
+		reason: string;
+		details: PreviewDetails;
+	}
+
+	interface PreviewFormat {
+		name: string;
+		score: number;
+	}
+
+	interface PreviewDetails {
+		qualityProfile: string;
+		fileName: string;
+		customFormats: PreviewFormat[];
+		score: number;
+		tags: string[];
+		monitored: boolean;
+		dateAdded: string;
+		sizeOnDisk: number;
+		releaseGroup: string;
+		status: string;
+	}
+
+	interface PreviewResult {
+		filterName: string;
+		totalItems: number;
+		matchedCount: number;
+		cooldownCount: number;
+		selectableCount: number;
+		selectedCount: number;
+		requestedCount: number;
+		selector: string;
+		items: PreviewItem[];
+	}
+
+	const dispatch = createEventDispatcher<{ close: void }>();
+
+	let searchStore: SearchStore = createSearchStore();
+	let debouncedQuery: Readable<string> = searchStore.debouncedQuery;
+	let loading = false;
+	let loadingText = 'Loading library data...';
+	let error: string | null = null;
+	let data: PreviewResult | null = null;
+	let statusFilters: Set<PreviewStatus> = new Set();
+	let expandedIds: Set<string | number> = new Set();
+	let requestId = 0;
+	let stepTimer: ReturnType<typeof setTimeout> | undefined;
+	let activePreviewKey = '';
+
+	const columns: Column<PreviewItem>[] = [
+		{ key: 'title', header: 'Title', sortable: true, width: 'w-64' },
+		{ key: 'status', header: 'Status', width: 'w-32' },
+		{ key: 'reason', header: 'Reason' }
+	];
+	const statusMeta: Record<PreviewStatus, { label: string; variant: PreviewLabelVariant }> = {
+		selected: { label: 'Will search next', variant: 'success' },
+		selectable: { label: 'Eligible later', variant: 'info' },
+		cooldown: { label: 'Already searched', variant: 'warning' },
+		filtered_out: { label: "Doesn't match", variant: 'secondary' }
+	};
+	const statusOptions: { value: PreviewStatus; label: string }[] = [
+		{ value: 'selected', label: 'Will search next' },
+		{ value: 'selectable', label: 'Eligible later' },
+		{ value: 'cooldown', label: 'Already searched' },
+		{ value: 'filtered_out', label: "Doesn't match" }
+	];
+	const skeletonRows = Array.from({ length: 8 });
+
+	$: filteredItems = filterItems(data?.items ?? [], $debouncedQuery, statusFilters);
+	$: previewKey = open && filter && instanceId ? `${instanceId}:${filter.id}` : '';
+	$: if (previewKey && previewKey !== activePreviewKey && filter && instanceId) {
+		activePreviewKey = previewKey;
+		void loadPreview(filter, instanceId);
+	}
+	$: if (!open && activePreviewKey) {
+		activePreviewKey = '';
+		requestId += 1;
+		clearStepTimer();
+		loading = false;
+	}
+
+	function clearStepTimer() {
+		if (stepTimer) {
+			clearTimeout(stepTimer);
+			stepTimer = undefined;
+		}
+	}
+
+	function resetFilters() {
+		searchStore.clear();
+		statusFilters = new Set();
+		expandedIds = new Set();
+	}
+
+	function filterItems(
+		items: PreviewItem[],
+		query: string,
+		statuses: Set<PreviewStatus>
+	): PreviewItem[] {
+		let result = items;
+		const queryLower = query.trim().toLowerCase();
+
+		if (queryLower) {
+			result = result.filter(
+				(item) =>
+					item.title.toLowerCase().includes(queryLower) ||
+					item.reason.toLowerCase().includes(queryLower) ||
+					statusMeta[item.status].label.toLowerCase().includes(queryLower)
+			);
+		}
+
+		if (statuses.size > 0) {
+			result = result.filter((item) => statuses.has(item.status));
+		}
+
+		return result;
+	}
+
+	function toggleStatus(status: PreviewStatus) {
+		if (statusFilters.has(status)) {
+			statusFilters.delete(status);
+		} else {
+			statusFilters.add(status);
+		}
+		statusFilters = new Set(statusFilters);
+	}
+
+	function clearStatusFilters() {
+		statusFilters = new Set();
+	}
+
+	async function loadPreview(targetFilter: FilterConfig, targetInstanceId: string) {
+		const currentRequestId = requestId + 1;
+		requestId = currentRequestId;
+		loading = true;
+		loadingText = 'Loading library data...';
+		error = null;
+		data = null;
+		resetFilters();
+		clearStepTimer();
+		stepTimer = setTimeout(() => {
+			if (currentRequestId === requestId) {
+				loadingText = 'Evaluating filter...';
+			}
+		}, 700);
+
+		try {
+			const response = await fetch(`/arr/${targetInstanceId}/upgrades/preview`, {
+				method: 'POST',
+				headers: { 'Content-Type': 'application/json' },
+				body: JSON.stringify({ filter: structuredClone(targetFilter) })
+			});
+			const result = await response.json().catch(() => ({}));
+
+			if (currentRequestId !== requestId) {
+				return;
+			}
+
+			if (!response.ok) {
+				throw new Error(result.error ?? 'Failed to preview filter');
+			}
+
+			data = result as PreviewResult;
+		} catch (err) {
+			if (currentRequestId === requestId) {
+				error = err instanceof Error ? err.message : 'Failed to preview filter';
+			}
+		} finally {
+			if (currentRequestId === requestId) {
+				clearStepTimer();
+				loading = false;
+			}
+		}
+	}
+
+	function closePreview() {
+		requestId += 1;
+		clearStepTimer();
+		loading = false;
+		data = null;
+		dispatch('close');
+	}
+
+	function formatSize(sizeGb: number): string {
+		if (!sizeGb) return 'None';
+		if (sizeGb >= 1) return `${sizeGb.toFixed(1)} GB`;
+		return `${Math.round(sizeGb * 1024)} MB`;
+	}
+
+	function formatDateValue(value: string): string {
+		if (!value) return 'Unknown';
+		const result = formatDate(value, $serverTimezone);
+		return result === '-' ? 'Unknown' : result;
+	}
+
+	function formatScore(score: number): string {
+		return score.toLocaleString();
+	}
+
+	function formatStatus(status: string): string {
+		if (!status) return 'Unknown';
+		return status
+			.replace(/([a-z])([A-Z])/g, '$1 $2')
+			.replace(/_/g, ' ')
+			.replace(/\b\w/g, (letter) => letter.toUpperCase());
+	}
+
+	function statusVariant(status: string): PreviewLabelVariant {
+		switch (status) {
+			case 'released':
+			case 'continuing':
+				return 'success';
+			case 'inCinemas':
+			case 'upcoming':
+				return 'info';
+			default:
+				return 'secondary';
+		}
+	}
+
+	function formatCount(value: number): string {
+		return value.toLocaleString();
+	}
+
+	function formatItemCount(count: number, singular: string, plural: string): string {
+		return `${formatCount(count)} ${count === 1 ? singular : plural}`;
+	}
+
+	function getSelectorLabel(selectorId: string): string {
+		return selectors.find((selector) => selector.id === selectorId)?.label ?? selectorId;
+	}
+
+	function getEligibleLaterCount(result: PreviewResult): number {
+		return Math.max(0, result.selectableCount - result.selectedCount);
+	}
+
+	function getDoesNotMatchCount(result: PreviewResult): number {
+		return Math.max(0, result.totalItems - result.matchedCount);
+	}
+
+	onDestroy(() => {
+		clearStepTimer();
+	});
+</script>
+
+<Modal
+	{open}
+	header={filter ? `Preview: ${filter.name}` : 'Preview Filter'}
+	size="2xl"
+	height="xl"
+	on:cancel={closePreview}
+>
+	<svelte:fragment slot="body">
+		{#if loading}
+			<div class="space-y-4">
+				<div class="flex items-center gap-2 text-sm text-neutral-600 dark:text-neutral-300">
+					<Loader2 size={16} class="animate-spin text-blue-600 dark:text-blue-400" />
+					<span>{loadingText}</span>
+				</div>
+				<div
+					class="overflow-hidden rounded-lg border border-neutral-300 dark:border-neutral-700/60"
+				>
+					{#each skeletonRows as _}
+						<div
+							class="flex gap-4 border-b border-neutral-200 p-4 last:border-0 dark:border-neutral-800"
+						>
+							<div class="h-4 w-2/5 animate-pulse rounded bg-neutral-200 dark:bg-neutral-800"></div>
+							<div class="h-4 w-24 animate-pulse rounded bg-neutral-200 dark:bg-neutral-800"></div>
+							<div class="h-4 w-28 animate-pulse rounded bg-neutral-200 dark:bg-neutral-800"></div>
+							<div class="h-4 w-16 animate-pulse rounded bg-neutral-200 dark:bg-neutral-800"></div>
+						</div>
+					{/each}
+				</div>
+			</div>
+		{:else if error}
+			<div
+				class="rounded-lg border border-red-200 bg-red-50 p-4 text-sm text-red-700 dark:border-red-900/50 dark:bg-red-950/30 dark:text-red-300"
+			>
+				{error}
+			</div>
+		{:else if data}
+			<div class="space-y-4">
+				<div
+					class="space-y-3 rounded-lg border border-neutral-300 bg-white p-4 dark:border-neutral-700/60 dark:bg-neutral-900"
+				>
+					<div class="flex">
+						<span class="w-24 shrink-0 text-sm font-medium text-neutral-500 dark:text-neutral-400">
+							Library
+						</span>
+						<span class="text-sm text-neutral-900 dark:text-neutral-100">
+							{formatItemCount(data.totalItems, 'item', 'items')} checked
+						</span>
+					</div>
+
+					<div class="flex">
+						<span class="w-24 shrink-0 text-sm font-medium text-neutral-500 dark:text-neutral-400">
+							Filter
+						</span>
+						<span class="text-sm text-neutral-900 dark:text-neutral-100">
+							"{data.filterName}"
+							<span class="mx-1 text-neutral-400">&rarr;</span>
+							<span class="font-mono font-medium">{formatCount(data.matchedCount)}</span>
+							matched
+							<span class="mx-1 text-neutral-400">&rarr;</span>
+							<span class="font-mono font-medium">{formatCount(data.selectableCount)}</span>
+							after cooldown
+						</span>
+					</div>
+
+					<div class="flex">
+						<span class="w-24 shrink-0 text-sm font-medium text-neutral-500 dark:text-neutral-400">
+							Selection
+						</span>
+						<span class="text-sm text-neutral-900 dark:text-neutral-100">
+							{getSelectorLabel(data.selector)}
+							<span class="font-mono font-medium">{formatCount(data.selectedCount)}</span>
+							of <span class="font-mono">{formatCount(data.requestedCount)}</span>
+							will search next
+							{#if getEligibleLaterCount(data) > 0}
+								<span class="mx-1 text-neutral-400">&rarr;</span>
+								{formatItemCount(getEligibleLaterCount(data), 'item', 'items')}
+								eligible later
+							{/if}
+						</span>
+					</div>
+
+					<div class="flex">
+						<span class="w-24 shrink-0 text-sm font-medium text-neutral-500 dark:text-neutral-400">
+							Cooldown
+						</span>
+						<span class="text-sm text-neutral-900 dark:text-neutral-100">
+							{formatItemCount(data.cooldownCount, 'item', 'items')} already searched,
+							{formatItemCount(getDoesNotMatchCount(data), 'item does', 'items do')}
+							not match
+						</span>
+					</div>
+				</div>
+
+				<ActionsBar className="md:justify-start">
+					<SearchAction {searchStore} placeholder="Search items..." responsive />
+					<ActionButton icon={CircleDot} hasDropdown square title="Filter by status">
+						<svelte:fragment slot="dropdown">
+							<Dropdown position="right" mobilePosition="middle" minWidth="12rem">
+								<DropdownHeader label="Status" />
+								<DropdownItem
+									label="All statuses"
+									selected={statusFilters.size === 0}
+									on:click={clearStatusFilters}
+								/>
+								{#each statusOptions as option}
+									<DropdownItem
+										label={option.label}
+										selected={statusFilters.has(option.value)}
+										on:click={() => toggleStatus(option.value)}
+									/>
+								{/each}
+							</Dropdown>
+						</svelte:fragment>
+					</ActionButton>
+				</ActionsBar>
+
+				<ExpandableTable
+					{columns}
+					data={filteredItems}
+					getRowId={(row) => row.id}
+					bind:expandedRows={expandedIds}
+					compact
+					responsive
+					flushExpanded
+					fixedLayout
+					pageSize={100}
+					emptyMessage="No preview items match."
+				>
+					<svelte:fragment slot="cell" let:row let:column>
+						{#if column.key === 'title'}
+							<div class="min-w-0">
+								<div class="truncate font-medium">{row.title}</div>
+								<div class="text-xs text-neutral-500 dark:text-neutral-400">{row.year}</div>
+							</div>
+						{:else if column.key === 'status'}
+							<Label variant={statusMeta[row.status].variant} size="sm" rounded="md">
+								{statusMeta[row.status].label}
+							</Label>
+						{:else if column.key === 'reason'}
+							<span class="break-words text-neutral-600 dark:text-neutral-300">
+								{row.reason}
+							</span>
+						{/if}
+					</svelte:fragment>
+
+					<svelte:fragment slot="expanded" let:row>
+						<div class="min-w-0 overflow-hidden p-4">
+							<div class="divide-y divide-neutral-200 dark:divide-neutral-800">
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										File on Disk
+									</div>
+									<div class="min-w-0">
+										{#if row.details.fileName}
+											<code
+												class="font-mono text-xs break-all text-neutral-600 dark:text-neutral-400"
+											>
+												{row.details.fileName}
+											</code>
+										{:else}
+											<div class="text-xs text-neutral-500 dark:text-neutral-400">No file</div>
+										{/if}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-2 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Custom Formats
+									</div>
+									<div class="min-w-0">
+										{#if row.details.customFormats.length > 0}
+											<div class="flex min-w-0 flex-wrap items-center gap-2">
+												{#each [...row.details.customFormats].sort((a, b) => b.score - a.score) as item}
+													<CustomFormatBadge name={item.name} score={item.score} />
+												{/each}
+											</div>
+										{:else}
+											<div class="text-xs text-neutral-500 dark:text-neutral-400">
+												No custom formats matched
+											</div>
+										{/if}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Profile
+									</div>
+									<div class="min-w-0 break-words text-sm text-neutral-900 dark:text-neutral-100">
+										{row.details.qualityProfile}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Score
+									</div>
+									<div class="font-mono text-sm text-neutral-900 dark:text-neutral-100">
+										{formatScore(row.details.score)}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Monitored
+									</div>
+									<div>
+										<Label
+											variant={row.details.monitored ? 'success' : 'secondary'}
+											size="sm"
+											rounded="md"
+										>
+											{row.details.monitored ? 'Yes' : 'No'}
+										</Label>
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Status
+									</div>
+									<div>
+										<Label variant={statusVariant(row.details.status)} size="sm" rounded="md">
+											{formatStatus(row.details.status)}
+										</Label>
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">Size</div>
+									<div class="font-mono text-sm text-neutral-900 dark:text-neutral-100">
+										{formatSize(row.details.sizeOnDisk)}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Added
+									</div>
+									<div class="font-mono text-sm text-neutral-900 dark:text-neutral-100">
+										{formatDateValue(row.details.dateAdded)}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-1 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">
+										Release Group
+									</div>
+									<div
+										class="min-w-0 break-words font-mono text-sm text-neutral-900 dark:text-neutral-100"
+									>
+										{row.details.releaseGroup || 'None'}
+									</div>
+								</div>
+
+								<div
+									class="grid grid-cols-1 gap-2 py-3 md:grid-cols-[10rem_minmax(0,1fr)] md:items-center"
+								>
+									<div class="text-xs font-medium text-neutral-500 dark:text-neutral-400">Tags</div>
+									<div class="min-w-0">
+										{#if row.details.tags.length > 0}
+											<div class="flex min-w-0 flex-wrap items-center gap-2">
+												{#each row.details.tags as tag}
+													<Label variant="secondary" size="sm" rounded="md">{tag}</Label>
+												{/each}
+											</div>
+										{:else}
+											<div class="text-xs text-neutral-500 dark:text-neutral-400">No tags</div>
+										{/if}
+									</div>
+								</div>
+							</div>
+						</div>
+					</svelte:fragment>
+				</ExpandableTable>
+			</div>
+		{/if}
+	</svelte:fragment>
+
+	<svelte:fragment slot="footer">
+		<div class="flex w-full justify-end">
+			<Button text="Close" on:click={closePreview} />
+		</div>
+	</svelte:fragment>
+</Modal>
diff --git a/src/routes/arr/[id]/upgrades/components/FilterSettings.svelte b/src/routes/arr/[id]/upgrades/components/FilterSettings.svelte
index 740d9957..4eeebb79 100644
--- a/src/routes/arr/[id]/upgrades/components/FilterSettings.svelte
+++ b/src/routes/arr/[id]/upgrades/components/FilterSettings.svelte
@@ -7,7 +7,8 @@
 		FileJson,
 		FileText,
 		Trash2,
-		Pencil
+		Pencil,
+		Eye
 	} from 'lucide-svelte';
 	import {
 		createEmptyFilterConfig,
@@ -15,7 +16,6 @@
 		getFilterField,
 		isGroup,
 		isRule,
-		searchRateLimits,
 		resolveTagLabel,
 		type DynamicFilterOptions,
 		type FilterConfig,
@@ -32,6 +32,7 @@
 	import type { Readable } from 'svelte/store';
 	import { page } from '$app/stores';
 	import FilterGroupComponent from './FilterGroup.svelte';
+	import FilterPreviewModal from './FilterPreviewModal.svelte';
 	import FormInput from '$ui/form/FormInput.svelte';
 	import NumberInput from '$ui/form/NumberInput.svelte';
 	import Dropdown from '$ui/dropdown/Dropdown.svelte';
@@ -117,6 +118,8 @@
 	let deleteModalOpen = false;
 	let filterToDelete: FilterConfig | null = null;
 	let pasteModalOpen = false;
+	let previewModalOpen = false;
+	let previewFilter: FilterConfig | null = null;
 
 	function confirmDelete(filter: FilterConfig) {
 		filterToDelete = filter;
@@ -348,6 +351,16 @@
 	function handlePasteCancel() {
 		pasteModalOpen = false;
 	}
+
+	function openPreview(filter: FilterConfig) {
+		previewFilter = filter;
+		previewModalOpen = true;
+	}
+
+	function closePreview() {
+		previewModalOpen = false;
+		previewFilter = null;
+	}
 </script>
 
 <div class="-mx-4 bg-neutral-50 px-4 pt-2 pb-2 md:-mx-8 md:px-8 dark:bg-neutral-900">
@@ -421,6 +434,12 @@
 					</div>
 					<!-- Mobile: buttons below name -->
 					<div class="flex flex-wrap items-center gap-1 md:hidden">
+						<Button
+							icon={Eye}
+							iconColor="text-blue-600 dark:text-blue-400"
+							tooltip="Preview"
+							on:click={() => openPreview(row)}
+						/>
 						<Button
 							icon={Power}
 							iconColor={row.enabled
@@ -455,6 +474,12 @@
 		<!-- Desktop: buttons in actions slot -->
 		<svelte:fragment slot="actions" let:row>
 			<div class="hidden items-center gap-1 md:flex">
+				<Button
+					icon={Eye}
+					iconColor="text-blue-600 dark:text-blue-400"
+					tooltip="Preview"
+					on:click={() => openPreview(row)}
+				/>
 				<Button
 					icon={Power}
 					iconColor={row.enabled
@@ -619,6 +644,13 @@
 	on:cancel={handleDeleteCancel}
 />
 
+<FilterPreviewModal
+	open={previewModalOpen}
+	filter={previewFilter}
+	instanceId={$page.params.id}
+	on:close={closePreview}
+/>
+
 <PasteModal
 	open={pasteModalOpen}
 	header="Import Filter"
diff --git a/src/routes/arr/[id]/upgrades/preview/+server.ts b/src/routes/arr/[id]/upgrades/preview/+server.ts
new file mode 100644
index 00000000..7d5f0f43
--- /dev/null
+++ b/src/routes/arr/[id]/upgrades/preview/+server.ts
@@ -0,0 +1,55 @@
+import { json } from '@sveltejs/kit';
+import type { RequestHandler } from '@sveltejs/kit';
+import { arrInstancesQueries } from '$db/queries/arrInstances.ts';
+import type { FilterConfig } from '$shared/upgrades/filters.ts';
+import { previewUpgradeFilter } from '$lib/server/upgrades/preview.ts';
+
+function isFilterConfig(value: unknown): value is FilterConfig {
+	if (!value || typeof value !== 'object') {
+		return false;
+	}
+
+	const filter = value as Partial<FilterConfig>;
+	return (
+		typeof filter.id === 'string' &&
+		typeof filter.name === 'string' &&
+		typeof filter.enabled === 'boolean' &&
+		typeof filter.selector === 'string' &&
+		typeof filter.count === 'number' &&
+		typeof filter.cutoff === 'number' &&
+		!!filter.group &&
+		typeof filter.group === 'object'
+	);
+}
+
+export const POST: RequestHandler = async ({ params, request }) => {
+	const instanceId = parseInt(params.id ?? '', 10);
+	if (!Number.isFinite(instanceId)) {
+		return json({ error: 'Invalid instance ID' }, { status: 400 });
+	}
+
+	const instance = arrInstancesQueries.getById(instanceId);
+	if (!instance) {
+		return json({ error: 'Instance not found' }, { status: 404 });
+	}
+
+	if (instance.type !== 'radarr' && instance.type !== 'sonarr') {
+		return json(
+			{ error: `Upgrade preview is not supported for ${instance.type}` },
+			{ status: 400 }
+		);
+	}
+
+	const body = await request.json().catch(() => null);
+	if (!body || typeof body !== 'object' || !('filter' in body) || !isFilterConfig(body.filter)) {
+		return json({ error: 'Invalid filter' }, { status: 400 });
+	}
+
+	try {
+		const preview = await previewUpgradeFilter(instance, body.filter);
+		return json(preview);
+	} catch (err) {
+		const message = err instanceof Error ? err.message : 'Failed to preview filter';
+		return json({ error: message }, { status: 500 });
+	}
+};