diff --git a/scripts/cleanup-outputs.js b/scripts/cleanup-outputs.js
new file mode 100644
index 0000000..5d3447f
--- /dev/null
+++ b/scripts/cleanup-outputs.js
@@ -0,0 +1,55 @@
+import { promises as fs } from 'fs';
+import path from 'path';
+
+const CWD = process.cwd();
+const README_PATH = path.join(CWD, 'README');
+const TESTS_DIR = path.join(CWD, 'tests');
+
+async function main() {
+  const readme = await fs.readFile(README_PATH, 'utf-8');
+  const modelBlocks = readme.match(/<!-- (?:MODELS|GEMINI)_START -->\n([\s\S]+?)\n<!-- MODELS_END -->/g) || [];
+  
+  const validFilenames = new Set();
+  modelBlocks.forEach(block => {
+    const lines = block.replace(/<!-- .*? -->/g, '').trim().split('\n');
+    lines.forEach(line => {
+      const trimmed = line.trim();
+      if (trimmed) {
+        validFilenames.add(`${trimmed.replace(/[\/:]/g, '_')}.js`);
+      }
+    });
+  });
+
+  if (validFilenames.size === 0) {
+    console.error('No models found in README. Aborting cleanup to prevent accidental data loss.');
+    return;
+  }
+
+  const testDirs = (await fs.readdir(TESTS_DIR, { withFileTypes: true }))
+    .filter(d => d.isDirectory())
+    .map(d => d.name);
+
+  let deletedCount = 0;
+
+  for (const dir of testDirs) {
+    for (const outSubDir of ['outputs', 'outputs_gemini']) {
+      const outPath = path.join(TESTS_DIR, dir, outSubDir);
+      try {
+        const files = await fs.readdir(outPath);
+        for (const file of files) {
+          if (file.endsWith('.js') && !validFilenames.has(file)) {
+            console.log(`Deleting stale output: ${dir}/${outSubDir}/${file}`);
+            await fs.unlink(path.join(outPath, file));
+            deletedCount++;
+          }
+        }
+      } catch (e) {
+        // Directory does not exist, move on
+      }
+    }
+  }
+
+  console.log(`Cleanup complete. Deleted ${deletedCount} stale files.`);
+}
+
+main().catch(console.error);