diff --git a/.github/workflows/web-tests.yml b/.github/workflows/web-tests.yml
index e2b5aa9186..ff75830066 100644
--- a/.github/workflows/web-tests.yml
+++ b/.github/workflows/web-tests.yml
@@ -25,7 +25,8 @@ jobs:
       - name: Check browser module syntax
         run: |
           node --check demo/web/app.mjs
+          node --check demo/web/batch.mjs
           node --check demo/web/output-directory.mjs
           node --check demo/web/worker.mjs
-      - name: Test folder output recovery
-        run: node --test demo/web/tests/output-directory.test.mjs
+      - name: Test browser converter helpers
+        run: node --test demo/web/tests/batch.test.mjs demo/web/tests/output-directory.test.mjs
diff --git a/demo/web/archive.mjs b/demo/web/archive.mjs
index a479f53bdd..fdcb24d89a 100644
--- a/demo/web/archive.mjs
+++ b/demo/web/archive.mjs
@@ -1,8 +1,9 @@
 import { BlobReader, Uint8ArrayReader, ZipReader, ZipWriter, configure } from "https://cdn.jsdelivr.net/npm/@zip.js/zip.js@2.7.57/lib/zip-no-worker.js/+esm";
+import { batchMemoryEstimate, batchOutputDirectory, MEMORY_LIMIT, memoryEstimate } from "./batch.mjs";
 
 configure({ useWebWorkers: false, useCompressionStream: false, chunkSize: 65536 });
 
-export const MEMORY_LIMIT = 256 * 1024 * 1024;
+export { batchMemoryEstimate, batchOutputDirectory, memoryEstimate, MEMORY_LIMIT };
 export const CONVERSION_LIMIT = 256 * 1024 * 1024;
 export const ICON_LIMIT = 16 * 1024 * 1024;
 const MAX_ENTRIES = 100000;
@@ -204,27 +205,6 @@ export class Archive {
   async close() { await this.reader.close(); }
 }
 
-export function memoryEstimate(archiveBytes, selectedBytes, libraryBytes, entries) {
-  return safeSize(Math.ceil(archiveBytes * 1.02) + selectedBytes * 4 + libraryBytes + entries * 1024 + 8 * 1024 * 1024);
-}
-
-export function batchMemoryEstimate(summaries, target, libraryBytes) {
-  if (target !== "linux" && target !== "windows") throw new Error(`Unsupported conversion target: ${target}`);
-  return summaries.reduce((total, summary) => safeSize(total + memoryEstimate(
-    summary.totalBytes,
-    target === "windows" ? summary.windowsSelectedBytes : summary.selectedBytes,
-    libraryBytes,
-    summary.files
-  )), 0);
-}
-
-export function batchOutputDirectory(name, index) {
-  if (!Number.isSafeInteger(index) || index < 0) throw new Error("Invalid app index");
-  const stem = String(name).replace(/\.zip$/iu, "").normalize("NFKC")
-    .replace(/[^A-Za-z0-9._-]+/gu, "-").replace(/^[.-]+/u, "").slice(0, 80).replace(/[. -]+$/u, "");
-  return `${String(index + 1).padStart(2, "0")}-${stem || "app"}`;
-}
-
 export function createPackageWriter(destination) {
   return new ZipWriter(destination, { level: 9, zip64: true, bufferedWrite: false, useWebWorkers: false, useCompressionStream: false, preventClose: true });
 }
diff --git a/demo/web/batch.mjs b/demo/web/batch.mjs
new file mode 100644
index 0000000000..5058dbea4f
--- /dev/null
+++ b/demo/web/batch.mjs
@@ -0,0 +1,27 @@
+export const MEMORY_LIMIT = 256 * 1024 * 1024;
+
+function safeSize(value) {
+  if (!Number.isSafeInteger(value) || value < 0) throw new Error("ZIP contains an unsupported file size");
+  return value;
+}
+
+export function memoryEstimate(archiveBytes, selectedBytes, libraryBytes, entries) {
+  return safeSize(Math.ceil(archiveBytes * 1.02) + selectedBytes * 4 + libraryBytes + entries * 1024 + 8 * 1024 * 1024);
+}
+
+export function batchMemoryEstimate(summaries, target, libraryBytes) {
+  if (target !== "linux" && target !== "windows") throw new Error(`Unsupported conversion target: ${target}`);
+  return summaries.reduce((total, summary) => safeSize(total + memoryEstimate(
+    summary.totalBytes,
+    target === "windows" ? summary.windowsSelectedBytes : summary.selectedBytes,
+    libraryBytes,
+    summary.files
+  )), 0);
+}
+
+export function batchOutputDirectory(name, index) {
+  if (!Number.isSafeInteger(index) || index < 0) throw new Error("Invalid app index");
+  const stem = String(name).replace(/\.zip$/iu, "").normalize("NFKC")
+    .replace(/[^A-Za-z0-9._-]+/gu, "-").replace(/^[.-]+/u, "").slice(0, 80).replace(/[. -]+$/u, "");
+  return `${String(index + 1).padStart(2, "0")}-${stem || "app"}`;
+}
diff --git a/demo/web/tests/archive.test.mjs b/demo/web/tests/archive.test.mjs
index 0bc401d74b..d0c2ca7c77 100644
--- a/demo/web/tests/archive.test.mjs
+++ b/demo/web/tests/archive.test.mjs
@@ -7,7 +7,7 @@ import { register } from "node:module";
 register("./cdn-loader.mjs", import.meta.url, { data: { url: process.env.ANYPS5_TEST_ZIP_URL, path: process.env.ANYPS5_TEST_ZIP_PATH } });
 
 const site = name => pathToFileURL(path.join(process.argv[2], name)).href;
-const { Archive, batchMemoryEstimate, batchOutputDirectory, memoryEstimate, MEMORY_LIMIT, ICON_LIMIT, packageArchive } = await import(site("archive.mjs"));
+const { Archive, memoryEstimate, MEMORY_LIMIT, ICON_LIMIT, packageArchive } = await import(site("archive.mjs"));
 const { BlobReader, BlobWriter, Uint8ArrayReader, Uint8ArrayWriter, ZipReader, ZipWriter } = await import(process.env.ANYPS5_TEST_ZIP_URL);
 await import("./archive-reserved.test.mjs");
 const { default: createRelinker } = await import(site("native/relinker_wasm.mjs"));
@@ -157,16 +157,6 @@ assert.equal(selfModuleSummary.warnings.length, 2);
 assert.match(selfModuleSummary.warnings.join(" "), /SELF container/u);
 await selfModule.close();
 assert(memoryEstimate(200 * 1024 ** 3, 1024, 1024, 100) > MEMORY_LIMIT);
-assert(batchMemoryEstimate([
-  { totalBytes: 1024, selectedBytes: 128, windowsSelectedBytes: 256, files: 2 },
-  { totalBytes: 2048, selectedBytes: 256, windowsSelectedBytes: 512, files: 3 }
-], "linux", 1024) > memoryEstimate(2048, 256, 1024, 3));
-assert.equal(batchOutputDirectory("First App.zip", 0), "01-First-App");
-assert.equal(batchOutputDirectory("First App.zip", 1), "02-First-App");
-assert.equal(batchOutputDirectory("CON.zip", 0), "01-CON");
-assert.equal(batchOutputDirectory("...zip", 0), "01-app");
-assert.throws(() => batchOutputDirectory("app.zip", -1), /Invalid app index/u);
-assert.throws(() => batchMemoryEstimate([], "macos", 0), /Unsupported conversion target/u);
 const invalid = native.Convert({ target: "unsupported" }, () => {});
 assert.equal(invalid.ok, false);
 console.log("Archive validation, missing-folder warnings and large-download budget verified");
diff --git a/demo/web/tests/batch.test.mjs b/demo/web/tests/batch.test.mjs
new file mode 100644
index 0000000000..b19827d72b
--- /dev/null
+++ b/demo/web/tests/batch.test.mjs
@@ -0,0 +1,30 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { batchMemoryEstimate, batchOutputDirectory, memoryEstimate, MEMORY_LIMIT } from "../batch.mjs";
+
+test("estimates all ZIP outputs against one shared memory limit", () => {
+  const summaries = [
+    { totalBytes: 1024, selectedBytes: 128, windowsSelectedBytes: 256, files: 2 },
+    { totalBytes: 2048, selectedBytes: 256, windowsSelectedBytes: 512, files: 3 }
+  ];
+
+  assert.equal(batchMemoryEstimate(summaries, "linux", 1024), summaries.reduce(
+    (total, summary) => total + memoryEstimate(summary.totalBytes, summary.selectedBytes, 1024, summary.files),
+    0
+  ));
+  assert.equal(batchMemoryEstimate(summaries, "windows", 1024), summaries.reduce(
+    (total, summary) => total + memoryEstimate(summary.totalBytes, summary.windowsSelectedBytes, 1024, summary.files),
+    0
+  ));
+  assert.throws(() => batchMemoryEstimate([], "macos", 0), /Unsupported conversion target/u);
+  assert.throws(() => batchMemoryEstimate([{ totalBytes: Number.MAX_SAFE_INTEGER, selectedBytes: 0, windowsSelectedBytes: 0, files: 0 }], "linux", 0), /unsupported file size/u);
+  assert.equal(MEMORY_LIMIT, 256 * 1024 * 1024);
+});
+
+test("creates safe and distinct ZIP folder names for duplicate app filenames", () => {
+  assert.equal(batchOutputDirectory("First App.zip", 0), "01-First-App");
+  assert.equal(batchOutputDirectory("First App.zip", 1), "02-First-App");
+  assert.equal(batchOutputDirectory("CON.zip", 0), "01-CON");
+  assert.equal(batchOutputDirectory("...zip", 0), "01-app");
+  assert.throws(() => batchOutputDirectory("app.zip", -1), /Invalid app index/u);
+});
diff --git a/demo/web/worker.mjs b/demo/web/worker.mjs
index 59232fffa1..735533fafe 100644
--- a/demo/web/worker.mjs
+++ b/demo/web/worker.mjs
@@ -1,4 +1,5 @@
-import { Archive, batchMemoryEstimate, batchOutputDirectory, CONVERSION_LIMIT, MEMORY_LIMIT, createPackageWriter, packageArchive } from "./archive.mjs";
+import { batchMemoryEstimate, batchOutputDirectory, MEMORY_LIMIT } from "./batch.mjs";
+import { Archive, CONVERSION_LIMIT, createPackageWriter, packageArchive } from "./archive.mjs";
 
 let archive;
 let inputs = [];