diff --git a/apps/web/package.json b/apps/web/package.json
index 787064e1..7aa1380c 100644
--- a/apps/web/package.json
+++ b/apps/web/package.json
@@ -8,7 +8,7 @@
     "lint": "eslint . --max-warnings 0",
     "preview": "next build && next start",
     "start": "next start",
-    "test": "pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/server/rate/__tests__/core-rate-architecture.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/server/rate/__tests__/item-model.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/server/rate/__tests__/item-directory.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/app/api/v1/rate/__tests__/write-paths.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/app/api/v1/rate/__tests__/spec-scope.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/app/api/v1/rate/__tests__/item-fields.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/logger.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/review-display.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/concurrency.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/merchant-profile-reads.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/merchant-review-risk.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/item-directory.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/watchlist-sizes.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/item-compare.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/catalog-listing.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/discount-verdict-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-detail-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-competitors.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/analyzer-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/sold-count.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/content-lang.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/image-url.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/client-messages.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/seo.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/offer-plausibility.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-market-stats.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/sitemap-lastmod.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/leaderboard-badge-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/focus-trap.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/display-truth.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/spec-template.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-spec-rows.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/sale-state.test.ts",
+    "test": "pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/server/rate/__tests__/core-rate-architecture.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/server/rate/__tests__/item-model.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/server/rate/__tests__/item-directory.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/app/api/v1/rate/__tests__/write-paths.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/app/api/v1/rate/__tests__/spec-scope.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/app/api/v1/rate/__tests__/item-fields.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/logger.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/review-display.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/concurrency.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/merchant-profile-reads.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/merchant-review-risk.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/item-directory.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/watchlist-sizes.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/item-compare.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/compare-params.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/catalog-listing.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/discount-verdict-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-detail-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-competitors.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/analyzer-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/sold-count.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/content-lang.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/image-url.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/client-messages.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/seo.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/offer-plausibility.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-market-stats.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/sitemap-lastmod.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/leaderboard-badge-copy.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/focus-trap.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/display-truth.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/spec-template.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/product-spec-rows.test.ts && pnpm --filter @repo/crawlers exec tsx --tsconfig ../web/tsconfig.test.json ../web/src/lib/__tests__/sale-state.test.ts",
     "typecheck": "tsc --noEmit"
   },
   "browserslist": [
diff --git a/apps/web/src/app/[locale]/compare/page.tsx b/apps/web/src/app/[locale]/compare/page.tsx
index 15455bb8..f9fd9113 100644
--- a/apps/web/src/app/[locale]/compare/page.tsx
+++ b/apps/web/src/app/[locale]/compare/page.tsx
@@ -9,6 +9,7 @@ import {
 } from '@/server/rate';
 import { resolveCompareSlugs } from '@/server/rate/item-compare';
 import { getItemSlugsFor } from '@/server/rate/item-directory';
+import { compareCategoryParam } from '@/lib/compare-params';
 import { normalizeRateLocale } from '@/lib/rate-i18n';
 import { defaultOpenGraph, fitTitle, fitDescription } from '@/lib/seo';
 import CompareWorkspace from '@/components/compare/CompareWorkspace';
@@ -22,7 +23,7 @@ export const dynamic = 'force-dynamic';
 
 type PageProps = {
   params: Promise<{ locale: string }>;
-  searchParams: Promise<{ slugs?: string; category?: string }>;
+  searchParams: Promise<{ slugs?: string; category?: string; cat?: string }>;
 };
 
 const VALID_CATEGORIES = new Set<CanonicalCategorySlug>([
@@ -121,7 +122,9 @@ export default async function ComparePhonesPage({
   setRequestLocale(locale);
   const lang = normalizeRateLocale(locale);
   const t = await getTranslations({ locale: lang, namespace: 'compare' });
-  const { slugs: slugsParam, category: categoryParam } = await searchParams;
+  const resolvedSearch = await searchParams;
+  const slugsParam = resolvedSearch.slugs;
+  const categoryParam = compareCategoryParam(resolvedSearch);
   const requestedSlugs = parseSlugsCsv(slugsParam);
 
   const [catalogCandidates, requestedProducts] = await Promise.all([
diff --git a/apps/web/src/lib/__tests__/compare-params.test.ts b/apps/web/src/lib/__tests__/compare-params.test.ts
new file mode 100644
index 00000000..6315f23b
--- /dev/null
+++ b/apps/web/src/lib/__tests__/compare-params.test.ts
@@ -0,0 +1,15 @@
+import assert from 'node:assert/strict';
+import { compareCategoryParam } from '../compare-params';
+
+// Compare links written with ?cat= open on their category (DOS/Rate#1303).
+assert.equal(compareCategoryParam({ cat: 'earbuds' }), 'earbuds');
+assert.equal(compareCategoryParam({ category: 'laptops' }), 'laptops');
+assert.equal(
+  compareCategoryParam({ category: 'laptops', cat: 'earbuds' }),
+  'laptops',
+  'category wins'
+);
+assert.equal(compareCategoryParam({ cat: ['tablets', 'x'] }), 'tablets');
+assert.equal(compareCategoryParam({}), undefined);
+assert.equal(compareCategoryParam({ category: '', cat: 'earbuds' }), 'earbuds');
+console.log('✅ compare params');
diff --git a/apps/web/src/lib/compare-params.ts b/apps/web/src/lib/compare-params.ts
new file mode 100644
index 00000000..66cb67d8
--- /dev/null
+++ b/apps/web/src/lib/compare-params.ts
@@ -0,0 +1,15 @@
+/**
+ * The compare page's category query parameter. Links across the site write
+ * `?cat=` (leaderboard, versus, home, category pages, the extension) while
+ * the page read only `?category=`, so those links opened on smartphones
+ * (DOS/Rate#1303). Both are read; `category` wins when both are set.
+ */
+export function compareCategoryParam(params: {
+  category?: string | string[];
+  cat?: string | string[];
+}): string | undefined {
+  const first = (v: string | string[] | undefined) =>
+    Array.isArray(v) ? v[0] : v;
+  // An empty value is no value, as in the API routes.
+  return first(params.category) || first(params.cat) || undefined;
+}