diff --git a/.gitignore b/.gitignore
index efbd9f5..8a9ef28 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,6 +6,7 @@
 # For our testing scripts
 /cache
 /test/fixtures/actual-results.json
+/test/fixtures-multithread
 
 # For DS Store
 **/.DS_Store
diff --git a/.vscode/extensions.json b/.vscode/extensions.json
index 35bd20b..312bb3a 100644
--- a/.vscode/extensions.json
+++ b/.vscode/extensions.json
@@ -8,5 +8,7 @@
     // "esbenp.prettier-vscode", // Prettier for consistent formatting / not maintained and causes crashes https://github.com/prettier/prettier-vscode/issues/3743
     "dbaeumer.vscode-eslint",
     "arcanis.vscode-zipfs" // Required to use Prettier with Yarn in VS Code
+    ,
+    "esbenp.prettier-vscode"
   ]
 }
diff --git a/package.json b/package.json
index d920d17..ac01d73 100644
--- a/package.json
+++ b/package.json
@@ -2,14 +2,14 @@
   "license": "UNLICENSED",
   "devDependencies": {
     "@shopify/prettier-plugin-liquid": "^1.9.3",
-    "better-sqlite3": "^11.10.0",
-    "cheerio": "^1.1.0",
+    "better-sqlite3": "^12.2.0",
+    "cheerio": "^1.1.2",
     "cli-progress": "^3.12.0",
     "css": "^3.0.0",
-    "glob": "^11.0.2",
-    "html-validate": "^9.5.5",
+    "glob": "^11.0.3",
+    "html-validate": "^10.0.0",
     "markdownlint-cli2": "^0.18.1",
-    "prettier": "^3.5.3",
+    "prettier": "^3.6.2",
     "shell-quote": "^1.8.3"
   },
   "scripts": {
diff --git a/test/build-html-validate.mjs b/test/build-html-validate.mjs
index d2ce5d5..cbf9826 100644
--- a/test/build-html-validate.mjs
+++ b/test/build-html-validate.mjs
@@ -1,67 +1,127 @@
-import { HtmlValidate, FileSystemConfigLoader, formatterFactory, esmResolver } from "html-validate";
 import { glob } from "glob";
 import cliProgress from "cli-progress";
+import { Worker } from "worker_threads";
+import path from "path";
+import { fileURLToPath } from "url";
+
+const __filename = fileURLToPath(import.meta.url);
+const __dirname = path.dirname(__filename);
 
 // In the future, the CLI may improve and this script may be unnecessary.
 // SEE: https://gitlab.com/html-validate/html-validate/-/issues/273
 
+// Configuration
+const MAX_WORKERS = parseInt(process.env.HTML_VALIDATE_WORKERS) || 4;
+const WORKER_SCRIPT_PATH = path.join(__dirname, "html-validate-worker.mjs");
+
 // Find and sort all HTML files in the 'build' directory
 const targets = glob.sync("build/**/*.html").sort();
 
-// Initialize HtmlValidate instance
-const resolver = esmResolver();
-const loader = new FileSystemConfigLoader([resolver]);
-const htmlValidate = new HtmlValidate(loader);
-const formatter = formatterFactory("stylish");
-let allTestsPassed = true;
-
-// Initialize progress bar
-const bar = new cliProgress.SingleBar({
-  format: "🧪 [{bar}] {percentage}% | {value}/{total} | ETA: {eta}s | {file}",
-  forceRedraw: true,
-});
-// Monkey-patch in logging support https://github.com/npkgz/cli-progress/issues/159#issuecomment-2959578474
-bar.loggingBuffer = [];
-bar.log = function (message) {
-  bar.loggingBuffer.push(message);
-};
-bar.on("redraw-pre", (data) => {
-  if (bar.loggingBuffer.length > 0) {
-    bar.terminal.clearLine();
-    bar.terminal.cursorTo(0);
-    while (bar.loggingBuffer.length > 0) {
-      bar.terminal.write(bar.loggingBuffer.shift());
-      bar.terminal.write("\n");
+if (targets.length === 0) {
+  console.log("⚠️  No HTML files found in build directory");
+  console.log("   Make sure to build the site first");
+  process.exit(0);
+}
+
+console.log(`🧪 Validating ${targets.length} files with ${MAX_WORKERS} parallel workers...`);
+
+await validateParallel();
+
+async function validateParallel() {
+  const multibar = new cliProgress.MultiBar({
+    format: "[{bar}] {percentage}% | {value}/{total} | {status}",
+    hideCursor: true,
+    clearOnComplete: false,
+    stopOnComplete: true,
+    forceRedraw: false,
+  }, cliProgress.Presets.shades_classic);
+
+  const overallBar = multibar.create(targets.length, 0, {
+    status: "Starting..."
+  });
+
+  let completedTasks = 0;
+  let allTestsPassed = true;
+  const results = [];
+  const workers = [];
+  const taskQueue = [...targets];
+
+  let isDone = false;
+  function completeParallelProcessing() {
+    if (isDone) return;
+    isDone = true;
+
+    multibar.stop();
+    workers.forEach(worker => worker.terminate());
+
+    const failedResults = results.filter(r => !r.isValid);
+    const passedCount = results.length - failedResults.length;
+
+    console.log("\n📊 Results summary:");
+    console.log(`✅ ${passedCount} files passed validation`);
+
+    if (failedResults.length > 0) {
+      console.log(`❌ ${failedResults.length} files failed validation`);
+      process.exit(1);
+    } else {
+      console.log("✨ All tests passed!\n");
     }
   }
-});
 
-console.log("🧪 Validating files...");
-bar.start(targets.length, 0, { file: "Starting..." });
+  function createWorker(workerId) {
+    const worker = new Worker(WORKER_SCRIPT_PATH);
 
-for (const target of targets) {
-  try {
-    bar.increment(0, { file: target });
-    const report = await htmlValidate.validateFile(target);
-    if (!report.valid) {
-      bar.log(formatter(report.results));
+    worker.on("message", (result) => {
+      completedTasks++;
+      results.push(result);
+
+      if (!result.isValid) {
+        allTestsPassed = false;
+        multibar.log(`❌ ${path.relative(process.cwd(), result.filePath)}\n${result.message.trim()}\n\n`);
+      }
+
+      overallBar.increment(1, {
+        status: path.basename(result.filePath),
+      });
+
+      if (taskQueue.length > 0) {
+        const nextTask = taskQueue.shift();
+        worker.postMessage({ filePath: nextTask, workerId });
+      }
+
+      if (completedTasks === targets.length) {
+        completeParallelProcessing();
+      }
+    });
+
+    worker.on("error", (error) => {
+      console.error(`Worker ${workerId} error:`, error);
       allTestsPassed = false;
-    } else {
-      bar.log(`✅ ${target}`);
-    }
-  } catch (error) {
-    bar.log(`❌ Error validating ${target}: ${error.message}`);
-    allTestsPassed = false;
+      completeParallelProcessing();
+    });
+
+    return worker;
   }
-  bar.increment(1);
-}
 
-bar.stop();
+  function startParallelProcessing() {
+    for (let i = 0; i < MAX_WORKERS; i++) {
+      const worker = createWorker(i);
+      workers.push(worker);
+    }
+
+    const initialTasks = Math.min(MAX_WORKERS, taskQueue.length);
+    for (let i = 0; i < initialTasks; i++) {
+      const task = taskQueue.shift();
+      workers[i].postMessage({ filePath: task, workerId: i });
+    }
+  }
 
-// Display final result
-if (allTestsPassed) {
-  console.log("✨ All tests passed!\n");
-} else {
-  console.log("❌ Some tests failed.\n");
-  process.exit(1);
+  return new Promise((resolve) => {
+    const originalComplete = completeParallelProcessing;
+    completeParallelProcessing = () => {
+      originalComplete();
+      resolve();
+    };
+    startParallelProcessing();
+  });
 }
diff --git a/test/html-validate-worker.mjs b/test/html-validate-worker.mjs
new file mode 100644
index 0000000..ba5f97e
--- /dev/null
+++ b/test/html-validate-worker.mjs
@@ -0,0 +1,37 @@
+import { parentPort, workerData } from "worker_threads";
+import { HtmlValidate, FileSystemConfigLoader, formatterFactory, esmResolver } from "html-validate";
+
+// Initialize HtmlValidate instance (same as main script)
+const resolver = esmResolver();
+const loader = new FileSystemConfigLoader([resolver]);
+const htmlValidate = new HtmlValidate(loader);
+const formatter = formatterFactory("text");
+
+// Listen for messages from parent thread
+parentPort.on("message", async (data) => {
+  const { filePath, workerId } = data;
+  
+  try {
+    const report = await htmlValidate.validateFile(filePath);
+    
+    const result = {
+      workerId,
+      filePath,
+      success: report.valid,
+      message: report.valid ? `✅ ${filePath}` : formatter(report.results),
+      isValid: report.valid,
+      report: report
+    };
+    
+    parentPort.postMessage(result);
+  } catch (error) {    const result = {
+      workerId,
+      filePath,
+      success: false,
+      message: `❌ Error validating`,
+      isValid: false
+    };
+    
+    parentPort.postMessage(result);
+  }
+});
\ No newline at end of file
diff --git a/yarn.lock b/yarn.lock
index 694f09b..f7389e8 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -14,6 +14,22 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@isaacs/balanced-match@npm:^4.0.1":
+  version: 4.0.1
+  resolution: "@isaacs/balanced-match@npm:4.0.1"
+  checksum: 10c0/7da011805b259ec5c955f01cee903da72ad97c5e6f01ca96197267d3f33103d5b2f8a1af192140f3aa64526c593c8d098ae366c2b11f7f17645d12387c2fd420
+  languageName: node
+  linkType: hard
+
+"@isaacs/brace-expansion@npm:^5.0.0":
+  version: 5.0.0
+  resolution: "@isaacs/brace-expansion@npm:5.0.0"
+  dependencies:
+    "@isaacs/balanced-match": "npm:^4.0.1"
+  checksum: 10c0/b4d4812f4be53afc2c5b6c545001ff7a4659af68d4484804e9d514e183d20269bb81def8682c01a22b17c4d6aed14292c8494f7d2ac664e547101c1a905aa977
+  languageName: node
+  linkType: hard
+
 "@isaacs/cliui@npm:^8.0.2":
   version: 8.0.2
   resolution: "@isaacs/cliui@npm:8.0.2"
@@ -261,14 +277,14 @@ __metadata:
   languageName: node
   linkType: hard
 
-"better-sqlite3@npm:^11.10.0":
-  version: 11.10.0
-  resolution: "better-sqlite3@npm:11.10.0"
+"better-sqlite3@npm:^12.2.0":
+  version: 12.2.0
+  resolution: "better-sqlite3@npm:12.2.0"
   dependencies:
     bindings: "npm:^1.5.0"
     node-gyp: "npm:latest"
     prebuild-install: "npm:^7.1.1"
-  checksum: 10c0/1fffbf9e5fc9d24847a3ecf09491bceab1c294b46ba41df1c449dc20b6f5c5d9d94ff24becd0b1632ee282bd21278b7fea53a5a6215bb99209ded0ae05eda3b0
+  checksum: 10c0/842247e9bbb775f366ac91f604117112c312497e643bac21648d8b69f479763de0ac049b14b609d6d5ecaee50debcc09a854f682d3dc099a1d933fea92ce68d0
   languageName: node
   linkType: hard
 
@@ -382,22 +398,22 @@ __metadata:
   languageName: node
   linkType: hard
 
-"cheerio@npm:^1.1.0":
-  version: 1.1.0
-  resolution: "cheerio@npm:1.1.0"
+"cheerio@npm:^1.1.2":
+  version: 1.1.2
+  resolution: "cheerio@npm:1.1.2"
   dependencies:
     cheerio-select: "npm:^2.1.0"
     dom-serializer: "npm:^2.0.0"
     domhandler: "npm:^5.0.3"
     domutils: "npm:^3.2.2"
-    encoding-sniffer: "npm:^0.2.0"
+    encoding-sniffer: "npm:^0.2.1"
     htmlparser2: "npm:^10.0.0"
     parse5: "npm:^7.3.0"
     parse5-htmlparser2-tree-adapter: "npm:^7.1.0"
     parse5-parser-stream: "npm:^7.1.2"
-    undici: "npm:^7.10.0"
+    undici: "npm:^7.12.0"
     whatwg-mimetype: "npm:^4.0.0"
-  checksum: 10c0/f7b940a89e1fe77bf6b4fe3b993f17b02a358942cc0b9d3b55ea235a0bc322829dbc47151763ef9986fd237494c00380909af759e46582c72470a10643b85abd
+  checksum: 10c0/2c6d2274666fe122f54fdca457ee76453e1a993b19563acaa23eb565bf7776f0f01e4c3800092f00e84aa13c83a161f0cf000ac0a8332d1d7f2b2387d6ecc5fc
   languageName: node
   linkType: hard
 
@@ -454,7 +470,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"cross-spawn@npm:^7.0.0":
+"cross-spawn@npm:^7.0.0, cross-spawn@npm:^7.0.6":
   version: 7.0.6
   resolution: "cross-spawn@npm:7.0.6"
   dependencies:
@@ -634,13 +650,13 @@ __metadata:
   languageName: node
   linkType: hard
 
-"encoding-sniffer@npm:^0.2.0":
-  version: 0.2.0
-  resolution: "encoding-sniffer@npm:0.2.0"
+"encoding-sniffer@npm:^0.2.1":
+  version: 0.2.1
+  resolution: "encoding-sniffer@npm:0.2.1"
   dependencies:
     iconv-lite: "npm:^0.6.3"
     whatwg-encoding: "npm:^3.1.1"
-  checksum: 10c0/b312e0d67f339bec44e021e5210ee8ee90d7b8f9975eb2c79a36fd467eb07709e88dcf62ee20f62ee0d74a13874307d99557852a2de9b448f1e3fb991fc68257
+  checksum: 10c0/d6b591880788f3baf8dd1744636dd189d24a1ec93e6f9817267c60ac3458a5191ca70ab1a186fb67731beff1c3489c6527dfdc4718158ed8460ab2f400dd5e7d
   languageName: node
   linkType: hard
 
@@ -776,6 +792,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"foreground-child@npm:^3.3.1":
+  version: 3.3.1
+  resolution: "foreground-child@npm:3.3.1"
+  dependencies:
+    cross-spawn: "npm:^7.0.6"
+    signal-exit: "npm:^4.0.1"
+  checksum: 10c0/8986e4af2430896e65bc2788d6679067294d6aee9545daefc84923a0a4b399ad9c7a3ea7bd8c0b2b80fdf4a92de4c69df3f628233ff3224260e9c1541a9e9ed3
+  languageName: node
+  linkType: hard
+
 "front-matter@npm:^4.0.2":
   version: 4.0.2
   resolution: "front-matter@npm:4.0.2"
@@ -826,7 +852,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"glob@npm:^10.0.0, glob@npm:^10.2.2, glob@npm:^10.3.10":
+"glob@npm:^10.2.2, glob@npm:^10.3.10":
   version: 10.4.5
   resolution: "glob@npm:10.4.5"
   dependencies:
@@ -842,19 +868,19 @@ __metadata:
   languageName: node
   linkType: hard
 
-"glob@npm:^11.0.2":
-  version: 11.0.2
-  resolution: "glob@npm:11.0.2"
+"glob@npm:^11.0.0, glob@npm:^11.0.3":
+  version: 11.0.3
+  resolution: "glob@npm:11.0.3"
   dependencies:
-    foreground-child: "npm:^3.1.0"
-    jackspeak: "npm:^4.0.1"
-    minimatch: "npm:^10.0.0"
+    foreground-child: "npm:^3.3.1"
+    jackspeak: "npm:^4.1.1"
+    minimatch: "npm:^10.0.3"
     minipass: "npm:^7.1.2"
     package-json-from-dist: "npm:^1.0.0"
     path-scurry: "npm:^2.0.0"
   bin:
     glob: dist/esm/bin.mjs
-  checksum: 10c0/49f91c64ca882d5e3a72397bd45a146ca91fd3ca53dafb5254daf6c0e83fc510d39ea66f136f9ac7ca075cdd11fbe9aaa235b28f743bd477622e472f4fdc0240
+  checksum: 10c0/7d24457549ec2903920dfa3d8e76850e7c02aa709122f0164b240c712f5455c0b457e6f2a1eee39344c6148e39895be8094ae8cfef7ccc3296ed30bce250c661
   languageName: node
   linkType: hard
 
@@ -886,23 +912,23 @@ __metadata:
   languageName: node
   linkType: hard
 
-"html-validate@npm:^9.5.5":
-  version: 9.5.5
-  resolution: "html-validate@npm:9.5.5"
+"html-validate@npm:^10.0.0":
+  version: 10.0.0
+  resolution: "html-validate@npm:10.0.0"
   dependencies:
     "@html-validate/stylish": "npm:^4.1.0"
     "@sidvind/better-ajv-errors": "npm:4.0.0"
     ajv: "npm:^8.0.0"
-    glob: "npm:^10.0.0"
+    glob: "npm:^11.0.0"
     kleur: "npm:^4.1.0"
     minimist: "npm:^1.2.0"
     prompts: "npm:^2.0.0"
     semver: "npm:^7.0.0"
   peerDependencies:
-    jest: ^27.1 || ^28.1.3 || ^29.0.3
-    jest-diff: ^27.1 || ^28.1.3 || ^29.0.3
-    jest-snapshot: ^27.1 || ^28.1.3 || ^29.0.3
-    vitest: ^0.34.0 || ^1.0.0 || ^2.0.0 || ^3.0.0
+    jest: ^28.1.3 || ^29.0.3 || ^30.0.0
+    jest-diff: ^28.1.3 || ^29.0.3 || ^30.0.0
+    jest-snapshot: ^28.1.3 || ^29.0.3 || ^30.0.0
+    vitest: ^1.0.0 || ^2.0.0 || ^3.0.0
   peerDependenciesMeta:
     jest:
       optional: true
@@ -914,7 +940,7 @@ __metadata:
       optional: true
   bin:
     html-validate: bin/html-validate.mjs
-  checksum: 10c0/ee1becce55d39aef19884509da887bdf7aea2952ece69c9ab1919c24690b673b22e4c76e2b5b65535a58da501d56e2441c639559bd88be472694d0381630a3b0
+  checksum: 10c0/39af9649a1990b0a70993951ed29ac5c7c769a0434c2e4248f0b66b2d6e04a27ee15f850f3f8e4e2eb62494bf2606f45af9f5193c11196056594fdbf29b8bc0e
   languageName: node
   linkType: hard
 
@@ -1129,12 +1155,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"jackspeak@npm:^4.0.1":
-  version: 4.0.2
-  resolution: "jackspeak@npm:4.0.2"
+"jackspeak@npm:^4.1.1":
+  version: 4.1.1
+  resolution: "jackspeak@npm:4.1.1"
   dependencies:
     "@isaacs/cliui": "npm:^8.0.2"
-  checksum: 10c0/b26039d11c0163a95b1e58851b9ac453cce64ad6d1eb98a00b303ad5eeb761b29d33c9419d1e16c016d3f7151c8edf7df223e6cf93a1907655fd95d6ce85c0de
+  checksum: 10c0/84ec4f8e21d6514db24737d9caf65361511f75e5e424980eebca4199f400874f45e562ac20fa8aeb1dd20ca2f3f81f0788b6e9c3e64d216a5794fd6f30e0e042
   languageName: node
   linkType: hard
 
@@ -1675,12 +1701,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"minimatch@npm:^10.0.0":
-  version: 10.0.1
-  resolution: "minimatch@npm:10.0.1"
+"minimatch@npm:^10.0.3":
+  version: 10.0.3
+  resolution: "minimatch@npm:10.0.3"
   dependencies:
-    brace-expansion: "npm:^2.0.1"
-  checksum: 10c0/e6c29a81fe83e1877ad51348306be2e8aeca18c88fdee7a99df44322314279e15799e41d7cb274e4e8bb0b451a3bc622d6182e157dfa1717d6cda75e9cd8cd5d
+    "@isaacs/brace-expansion": "npm:^5.0.0"
+  checksum: 10c0/e43e4a905c5d70ac4cec8530ceaeccb9c544b1ba8ac45238e2a78121a01c17ff0c373346472d221872563204eabe929ad02669bb575cb1f0cc30facab369f70f
   languageName: node
   linkType: hard
 
@@ -2008,12 +2034,12 @@ __metadata:
   languageName: node
   linkType: hard
 
-"prettier@npm:^3.5.3":
-  version: 3.5.3
-  resolution: "prettier@npm:3.5.3"
+"prettier@npm:^3.6.2":
+  version: 3.6.2
+  resolution: "prettier@npm:3.6.2"
   bin:
     prettier: bin/prettier.cjs
-  checksum: 10c0/3880cb90b9dc0635819ab52ff571518c35bd7f15a6e80a2054c05dbc8a3aa6e74f135519e91197de63705bcb38388ded7e7230e2178432a1468005406238b877
+  checksum: 10c0/488cb2f2b99ec13da1e50074912870217c11edaddedeadc649b1244c749d15ba94e846423d062e2c4c9ae683e2d65f754de28889ba06e697ac4f988d44f45812
   languageName: node
   linkType: hard
 
@@ -2119,15 +2145,15 @@ __metadata:
   resolution: "root-workspace-0b6124@workspace:."
   dependencies:
     "@shopify/prettier-plugin-liquid": "npm:^1.9.3"
-    better-sqlite3: "npm:^11.10.0"
-    cheerio: "npm:^1.1.0"
+    better-sqlite3: "npm:^12.2.0"
+    cheerio: "npm:^1.1.2"
     cli-progress: "npm:^3.12.0"
     css: "npm:^3.0.0"
     front-matter: "npm:^4.0.2"
-    glob: "npm:^11.0.2"
-    html-validate: "npm:^9.5.5"
+    glob: "npm:^11.0.3"
+    html-validate: "npm:^10.0.0"
     markdownlint-cli2: "npm:^0.18.1"
-    prettier: "npm:^3.5.3"
+    prettier: "npm:^3.6.2"
     shell-quote: "npm:^1.8.3"
     xml2js: "npm:^0.6.2"
   dependenciesMeta:
@@ -2425,10 +2451,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"undici@npm:^7.10.0":
-  version: 7.10.0
-  resolution: "undici@npm:7.10.0"
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