diff --git a/src/lib/format.test.ts b/src/lib/format.test.ts
new file mode 100644
index 0000000..dfcdde1
--- /dev/null
+++ b/src/lib/format.test.ts
@@ -0,0 +1,42 @@
+import { compareVersions, formatBytes, formatCount, percent } from "./format";
+
+function assert(condition: boolean, message: string) {
+  if (!condition) {
+    throw new Error(`Assertion failed: ${message}`);
+  }
+}
+
+function runTests() {
+  // basic version comparison
+  assert(compareVersions("1.2.10", "1.2.9") > 0, "1.2.10 > 1.2.9");
+  assert(compareVersions("1.2.9", "1.2.10") < 0, "1.2.9 < 1.2.10");
+  assert(compareVersions("1.2.3", "1.2.3") === 0, "1.2.3 === 1.2.3");
+
+  // segment length mismatch
+  assert(compareVersions("1.2", "1.2.1") < 0, "1.2 < 1.2.1");
+  assert(compareVersions("1.2.1", "1.2") > 0, "1.2.1 > 1.2");
+  assert(compareVersions("1.2.0", "1.2") === 0, "1.2.0 === 1.2");
+
+  // multi-digit segments
+  assert(compareVersions("2.0.15", "2.0.2") > 0, "2.0.15 > 2.0.2");
+  assert(compareVersions("100.0.0", "99.99.99") > 0, "100.0.0 > 99.99.99");
+
+  // formatCount
+  assert(formatCount(500) === "500", "500 formatCount");
+  assert(formatCount(1500) === "2k", "1500 formatCount");
+  assert(formatCount(1842000) === "1.8M", "1842000 formatCount");
+
+  // formatBytes
+  assert(formatBytes(500) === "500 B", "500 B formatBytes");
+  assert(formatBytes(2048) === "2 KB", "2 KB formatBytes");
+  assert(formatBytes(2097152) === "2.0 MB", "2.0 MB formatBytes");
+
+  // percent
+  assert(percent(50, 100) === 50, "50% percent");
+  assert(percent(1, 0) === 0, "0 percent when total 0");
+  assert(percent(150, 100) === 100, "100% max percent");
+
+  console.log("All format tests passed successfully.");
+}
+
+runTests();
diff --git a/src/lib/format.ts b/src/lib/format.ts
index 345259d..dd53555 100644
--- a/src/lib/format.ts
+++ b/src/lib/format.ts
@@ -19,13 +19,41 @@ export function percent(received: number, total: number): number {
   return Math.min(100, Math.round((received / total) * 100));
 }
 
-/** Compare "1.2.10" vs "1.2.9" numerically per segment. Good enough for mod versions. */
+/**
+ * Compare "1.2.10" vs "1.2.9" numerically per segment. Good enough for mod versions.
+ * Single-pass index scanner to avoid array allocations (.split/.map) during list sorting.
+ */
 export function compareVersions(a: string, b: string): number {
-  const pa = a.split(".").map((s) => parseInt(s, 10) || 0);
-  const pb = b.split(".").map((s) => parseInt(s, 10) || 0);
-  for (let i = 0; i < Math.max(pa.length, pb.length); i++) {
-    const diff = (pa[i] ?? 0) - (pb[i] ?? 0);
-    if (diff !== 0) return diff;
+  let i = 0;
+  let j = 0;
+  const lenA = a.length;
+  const lenB = b.length;
+
+  while (i < lenA || j < lenB) {
+    let numA = 0;
+    while (i < lenA && a.charCodeAt(i) !== 46 /* '.' */) {
+      const code = a.charCodeAt(i);
+      if (code >= 48 && code <= 57) {
+        numA = numA * 10 + (code - 48);
+      }
+      i++;
+    }
+    if (i < lenA) i++; // skip '.'
+
+    let numB = 0;
+    while (j < lenB && b.charCodeAt(j) !== 46 /* '.' */) {
+      const code = b.charCodeAt(j);
+      if (code >= 48 && code <= 57) {
+        numB = numB * 10 + (code - 48);
+      }
+      j++;
+    }
+    if (j < lenB) j++; // skip '.'
+
+    if (numA !== numB) {
+      return numA - numB;
+    }
   }
+
   return 0;
 }
diff --git a/src/pages/InstalledPage.tsx b/src/pages/InstalledPage.tsx
index ef1b9df..c0173f2 100644
--- a/src/pages/InstalledPage.tsx
+++ b/src/pages/InstalledPage.tsx
@@ -437,6 +437,11 @@ export default function InstalledPage() {
 
   const mods = snapshot?.mods ?? [];
 
+  const collator = useMemo(
+    () => new Intl.Collator(undefined, { sensitivity: "base" }),
+    [],
+  );
+
   const { enabledMods, disabledMods } = useMemo(() => {
     const enabled: InstalledMod[] = [];
     const disabled: InstalledMod[] = [];
@@ -447,13 +452,13 @@ export default function InstalledPage() {
         disabled.push(m);
       }
     }
+    // Reusing Intl.Collator instance avoids creating collators repeatedly during sorting
     const cmp = (a: InstalledMod, b: InstalledMod) =>
-      a.name.localeCompare(b.name, undefined, { sensitivity: "base" }) ||
-      a.name.localeCompare(b.name);
+      collator.compare(a.name, b.name) || (a.name < b.name ? -1 : a.name > b.name ? 1 : 0);
     enabled.sort(cmp);
     disabled.sort(cmp);
     return { enabledMods: enabled, disabledMods: disabled };
-  }, [mods]);
+  }, [mods, collator]);
 
   useThumbnails(mods.map((m) => m.name));