diff --git a/src/data/pricing.ts b/src/data/pricing.ts
index 7820463..45a21f8 100644
--- a/src/data/pricing.ts
+++ b/src/data/pricing.ts
@@ -154,3 +154,21 @@ export const FREE_FEATURES: readonly string[] = [
   'Managing groups',
   'Find My',
 ] as const;
+
+/** macOS releases the Swift server runs on.
+ *
+ *  Names and numbers come from the server's own `docs/MACOS_COMPATIBILITY.md`.
+ *  The floor is 14: `Package.swift` declares `.macOS(.v14)`, so there is nothing
+ *  below it to offer. Note the numbering jumps 15 -> 26; Apple moved to
+ *  year-based versions, and 16 through 25 do not exist.
+ */
+export interface MacOSRelease {
+  version: number;
+  name: string;
+}
+
+export const MACOS_RELEASES: readonly MacOSRelease[] = [
+  { version: 14, name: 'Sonoma' },
+  { version: 15, name: 'Sequoia' },
+  { version: 26, name: 'Tahoe' },
+] as const;
diff --git a/src/pages/pricing/index.astro b/src/pages/pricing/index.astro
index 36ac8ed..b012b0e 100644
--- a/src/pages/pricing/index.astro
+++ b/src/pages/pricing/index.astro
@@ -16,8 +16,13 @@
  */
 import BaseLayout from '@layouts/BaseLayout.astro';
 import PageHeader from '@components/PageHeader.astro';
-import { PLANS, PRO_FEATURES, FREE_FEATURES } from '@data/pricing';
+import { PLANS, PRO_FEATURES, FREE_FEATURES, MACOS_RELEASES } from '@data/pricing';
 import { LINKS } from '@data/site';
+
+// Default the picker to the newest release, so the list opens on the full
+// feature set. Derived from the data rather than hardcoded, so adding macOS 27
+// to MACOS_RELEASES moves the default automatically.
+const newestMacOS = MACOS_RELEASES.reduce((a, b) => (b.version > a.version ? b : a));
 ---
 
 <BaseLayout
@@ -69,10 +74,62 @@ import { LINKS } from '@data/site';
         minimum macOS version, shown alongside it.
       </p>
 
+      <div class="mt-6 flex flex-wrap items-center gap-3">
+        <label for="macos-filter" class="text-sm font-medium text-strong">
+          Your server Mac runs
+        </label>
+        {/*
+          appearance-none plus our own chevron. The native arrow sits inside the
+          right padding, and on a rounded-full pill the 18.5px corner radius
+          curves in over it, so it reads as crammed against the edge. Drawing it
+          ourselves also makes it match the FAQ accordion's chevron and follow
+          the theme, which the native control does not.
+        */}
+        <div class="relative inline-flex">
+          <select
+            id="macos-filter"
+            class="appearance-none rounded-full border border-line bg-page py-2 pl-4 pr-10
+                   text-sm font-medium text-strong
+                   focus-visible:border-accent focus-visible:outline-2
+                   focus-visible:outline-offset-2 focus-visible:outline-accent"
+          >
+            {
+              MACOS_RELEASES.map((release) => (
+                <option value={release.version} selected={release.version === newestMacOS.version}>
+                  {release.name} ({release.version})
+                </option>
+              ))
+            }
+          </select>
+          <svg
+            class="pointer-events-none absolute right-3.5 top-1/2 size-4 -translate-y-1/2 text-muted"
+            viewBox="0 0 20 20"
+            fill="none"
+            stroke="currentColor"
+            stroke-width="2"
+            aria-hidden="true"
+          >
+            <path d="M5 7.5 10 12.5 15 7.5" stroke-linecap="round" stroke-linejoin="round"></path>
+          </svg>
+        </div>
+        <p id="macos-summary" role="status" aria-live="polite" class="text-sm text-muted">
+          {PRO_FEATURES.filter((f) => f.macos <= newestMacOS.version).length} of {
+            PRO_FEATURES.length
+          } Pro features run on {newestMacOS.name} ({newestMacOS.version}).
+        </p>
+      </div>
+
       <ul class="mt-6 grid gap-4 sm:grid-cols-2">
         {
           PRO_FEATURES.map((feature) => (
-            <li class="rounded-card border border-line bg-raised p-5">
+            <li
+              data-feature
+              data-macos={feature.macos}
+              data-state={feature.macos <= newestMacOS.version ? 'included' : 'excluded'}
+              class="rounded-card border border-line bg-raised p-5 transition
+                     data-[state=included]:border-accent data-[state=included]:bg-accent-solid/5
+                     data-[state=excluded]:opacity-55"
+            >
               <div class="flex items-start justify-between gap-3">
                 <h3 class="font-semibold text-strong">{feature.title}</h3>
                 <span class="shrink-0 rounded-full border border-line px-2 py-0.5 text-xs font-medium text-muted">
@@ -80,6 +137,18 @@ import { LINKS } from '@data/site';
                 </span>
               </div>
               <p class="mt-2 text-sm text-muted">{feature.summary}</p>
+              {/* Text, not just colour: the state has to survive greyscale and a
+                  screen reader. Rendered server-side for the default selection,
+                  so this is correct before the script runs and without it. */}
+              <p
+                data-verdict
+                class:list={[
+                  'mt-3 text-xs font-semibold',
+                  feature.macos <= newestMacOS.version ? 'text-accent' : 'text-muted',
+                ]}
+              >
+                {feature.macos <= newestMacOS.version ? '✓ Included' : `Needs macOS ${feature.macos}`}
+              </p>
             </li>
           ))
         }
@@ -123,3 +192,53 @@ import { LINKS } from '@data/site';
     </div>
   </div>
 </BaseLayout>
+
+<script>
+  // Highlights which Pro features a given macOS release can actually run.
+  //
+  // The rule is cumulative: a release includes everything introduced at or below
+  // its own version, so Tahoe (26) gets the Sequoia and Sonoma features too.
+  // That is a `<=` on the major version and nothing more -- the catalogue's
+  // minimums are the only input.
+  const select = document.getElementById('macos-filter') as HTMLSelectElement | null;
+  const summary = document.getElementById('macos-summary');
+  const cards = [...document.querySelectorAll<HTMLElement>('[data-feature]')];
+
+  if (select && cards.length) {
+    const names = new Map<number, string>(
+      [...select.options]
+        .filter((option) => option.value !== '0')
+        .map((option) => [Number(option.value), option.textContent?.trim() ?? ''])
+    );
+
+    const apply = () => {
+      const chosen = Number(select.value);
+      if (!chosen) return;
+
+      let included = 0;
+      for (const card of cards) {
+        const needs = Number(card.dataset.macos);
+        const ok = needs <= chosen;
+        if (ok) included += 1;
+        card.dataset.state = ok ? 'included' : 'excluded';
+
+        const verdict = card.querySelector<HTMLElement>('[data-verdict]');
+        if (verdict) {
+          verdict.textContent = ok ? '✓ Included' : `Needs macOS ${needs}`;
+          verdict.className = ok
+            ? 'mt-3 text-xs font-semibold text-accent'
+            : 'mt-3 text-xs font-semibold text-muted';
+        }
+      }
+
+      if (summary) {
+        const label = names.get(chosen) ?? String(chosen);
+        summary.textContent = `${included} of ${cards.length} Pro features run on ${label}.`;
+      }
+    };
+
+    select.addEventListener('change', apply);
+    // Browsers restore a previous selection on reload; reflect it immediately.
+    apply();
+  }
+</script>