diff --git a/pages/src/lib/Primes.svelte b/pages/src/lib/Primes.svelte
index 1e6ba50..d4d3316 100644
--- a/pages/src/lib/Primes.svelte
+++ b/pages/src/lib/Primes.svelte
@@ -93,6 +93,19 @@
         {/if}
     </div>
     <div class="card-body text-center d-flex flex-column justify-content-center align-items-center">
+        <div class="row w-100">
+            <div class="col">
+                <input
+                    type="range"
+                    id="{id}_toNumber"
+                    bind:value={toNumber}
+                    class="form-range"
+                    min={10_000}
+                    max={1_000_000}
+                    step={10_000}
+                >
+            </div>
+        </div>
         {#if !work}
             <p>Press <span class="badge text-bg-primary">Start</span> to discover primes.</p>
         {:else}
diff --git a/pages/src/routes/+page.svelte b/pages/src/routes/+page.svelte
index a9dddd1..022cc82 100644
--- a/pages/src/routes/+page.svelte
+++ b/pages/src/routes/+page.svelte
@@ -23,13 +23,13 @@
         <Instructions />
         <div class="row row-cols-sm-2 row-cols-md-3">
             <div class="col">
-                <Primes toNumber={100_000} worker={exWorker} />
+                <Primes toNumber={200_000} worker={exWorker} />
             </div>
             <div class="col">
-                <Primes toNumber={110_000} worker={exWorker} />
+                <Primes toNumber={250_000} worker={exWorker} />
             </div>
             <div class="col">
-                <Primes toNumber={120_000} worker={exWorker} />
+                <Primes toNumber={300_000} worker={exWorker} />
             </div>
         </div>
     </div>
diff --git a/pages/vite.config.ts b/pages/vite.config.ts
index 652712c..c2154bc 100644
--- a/pages/vite.config.ts
+++ b/pages/vite.config.ts
@@ -1,15 +1,22 @@
 import { sveltekit } from '@sveltejs/kit/vite';
-import { defineConfig } from 'vite';
+import { defineConfig, type ConfigEnv, type PreviewServer, type ViteDevServer } from 'vite';
 
-export default defineConfig({
-	plugins: [sveltekit(), {
-		name: "configure-response-headers",
-		configureServer: (server) => {
-			server.middlewares.use((_req, res, next) => {
-				res.setHeader("Cross-Origin-Embedder-Policy", "require-corp");
-				res.setHeader("Cross-Origin-Opener-Policy", "same-origin");
-				next();
-			});
-		},
-	}]
-});
+function crossOriginIsolationMiddleware(server: PreviewServer | ViteDevServer) {
+	server.middlewares.use((_req, res, next) => {
+		res.setHeader("Cross-Origin-Embedder-Policy", "require-corp");
+		res.setHeader("Cross-Origin-Opener-Policy", "same-origin");
+		next();
+	});
+}
+
+const withoutCrossOriginIsolation = 'no-coi';
+
+export default function ({ mode }: ConfigEnv) {
+	return defineConfig({
+		plugins: [sveltekit(), {
+			name: "configure-response-headers",
+			configureServer: mode === withoutCrossOriginIsolation ? undefined : crossOriginIsolationMiddleware,
+			configurePreviewServer: mode === withoutCrossOriginIsolation ? undefined : crossOriginIsolationMiddleware,
+		}],
+	});
+};