diff --git a/web/server.py b/web/server.py
index 7e94281..ce16644 100644
--- a/web/server.py
+++ b/web/server.py
@@ -251,6 +251,28 @@ def cancel_job():
     except Exception as e:
         return jsonify({'error': str(e)}), 500
 
+@app.route('/api/clear-data', methods=['POST'])
+def clear_data():
+    """Delete all files from every county data directory under /data."""
+    counties = get_counties()
+    removed = []
+    errors = []
+    for county in counties:
+        county_dir = f'/data/{county["id"]}'
+        if not os.path.isdir(county_dir):
+            continue
+        for fname in os.listdir(county_dir):
+            fpath = os.path.join(county_dir, fname)
+            if os.path.isfile(fpath):
+                try:
+                    os.remove(fpath)
+                    removed.append(f'{county["id"]}/{fname}')
+                except Exception as e:
+                    errors.append(str(e))
+    if errors:
+        return jsonify({'error': '; '.join(errors)}), 500
+    return jsonify({'success': True, 'removed': removed})
+
 @app.route('/api/upload-file', methods=['POST'])
 def upload_file():
     """Upload a shapefile ZIP to a path under /data"""
diff --git a/web/templates/index.html b/web/templates/index.html
index 4889dc7..c6686c7 100644
--- a/web/templates/index.html
+++ b/web/templates/index.html
@@ -376,6 +376,7 @@
         <h1>OSM Import Tools</h1>
         <div class="topbar-sep"></div>
         <button class="btn-topbar" onclick="runScript('ls', '')">List Files</button>
+        <button class="btn-topbar" onclick="clearData()" style="color:#f88;">Clear Data</button>
         <div style="flex:1"></div>
         <div class="config-group">
             <a href="/api/config/counties.yml" class="btn-topbar-icon" title="Download counties.yml">↓ counties.yml</a>
@@ -725,6 +726,21 @@
         .finally(() => enableButtons());
     }
 
+    function clearData() {
+        if (!confirm('Delete all downloaded and processed files from all county folders?')) return;
+        fetch('/api/clear-data', { method: 'POST' })
+        .then(r => r.json())
+        .then(data => {
+            if (data.error) {
+                showStatus(`Error: ${data.error}`, 'error');
+            } else {
+                showStatus(`Cleared ${data.removed.length} file(s).`, 'success');
+                setTimeout(() => window.location.reload(), 800);
+            }
+        })
+        .catch(err => showStatus(`Error: ${err.message}`, 'error'));
+    }
+
     function uploadConfig(filename, input) {
         if (!input.files.length) return;
         const formData = new FormData();