diff --git a/test_upload.php b/test_upload.php
new file mode 100644
index 0000000..f954986
--- /dev/null
+++ b/test_upload.php
@@ -0,0 +1,38 @@
+<?php
+ini_set('display_errors', '1');
+error_reporting(E_ALL);
+require_once __DIR__ . '/db.php';
+
+echo "<h3>Test: dbLoadCompanies + dbSaveCompany</h3>";
+
+try {
+    $companies = dbLoadCompanies();
+    echo "Yrityksiä: " . count($companies) . "\n\n";
+
+    foreach ($companies as $comp) {
+        echo "ID: {$comp['id']}, nimi: {$comp['nimi']}, logo: " . ($comp['logo_file'] ?? '(tyhjä)') . "\n";
+        echo "  domains: " . json_encode($comp['domains']) . "\n";
+        echo "  cors_origins: " . var_export($comp['cors_origins'] ?? null, true) . "\n";
+        echo "  aktiivinen: " . var_export($comp['aktiivinen'], true) . "\n\n";
+    }
+
+    // Testaa save web1:lle (logo_file = test)
+    echo "--- Testataan save web1 (logo_file = 'test.png') ---\n";
+    foreach ($companies as $comp) {
+        if ($comp['id'] === 'web1') {
+            $comp['logo_file'] = 'test.png';
+            dbSaveCompany($comp);
+            echo "✅ dbSaveCompany OK\n";
+
+            // Palauta takaisin
+            $comp['logo_file'] = '';
+            dbSaveCompany($comp);
+            echo "✅ Palautus OK\n";
+            break;
+        }
+    }
+} catch (Throwable $e) {
+    echo "❌ VIRHE: " . $e->getMessage() . "\n";
+    echo "File: " . $e->getFile() . ":" . $e->getLine() . "\n";
+    echo "Trace:\n" . $e->getTraceAsString() . "\n";
+}