diff --git a/test.html b/test.html
index 7cabb63..5697ed1 100644
--- a/test.html
+++ b/test.html
@@ -11,7 +11,7 @@
       font-weight: normal;
       font-style: normal;
     }
-    body, input, select, button, a, label {
+    body, input, select, button, a, label, code, pre {
       font-family: "Stain", sans-serif;
     }
     .checker {
@@ -27,18 +27,19 @@
   <script src="https://cdn.tailwindcss.com"></script>
 </head>
 <body class="bg-white text-neutral-800 min-h-screen">
-  <main class="max-w-5xl mx-auto px-4 py-8 flex flex-col gap-6">
+  <main class="max-w-6xl mx-auto px-4 py-8 flex flex-col gap-6">
     <header class="flex items-center justify-between">
       <h1 class="text-4xl tracking-tight">bg test<span class="text-neutral-400">.lol</span></h1>
       <a href="/" class="text-sm underline text-neutral-500 hover:text-neutral-800">back to vibegif</a>
     </header>
 
     <p class="text-neutral-500">
-      Upload image(s), run <code>@imgly/background-removal</code>, compare results. First run may take longer (model download).
+      Upload image(s), run <code>@imgly/background-removal</code>, inspect output + logs.
+      First run can take longer due model download.
     </p>
 
-    <section class="grid md:grid-cols-4 gap-4">
-      <div class="flex flex-col gap-2">
+    <section class="grid md:grid-cols-5 gap-4">
+      <div class="flex flex-col gap-2 md:col-span-2">
         <label class="text-xs text-neutral-400 uppercase tracking-wider">Files</label>
         <input id="inp-files" type="file" accept="image/*" multiple class="border border-neutral-300 rounded-lg px-3 py-2" />
       </div>
@@ -73,12 +74,18 @@
       <p id="status" class="text-sm text-neutral-500"></p>
     </section>
 
+    <section class="border border-neutral-200 rounded-xl p-3">
+      <div class="flex items-center justify-between mb-2">
+        <p class="text-xs text-neutral-400 uppercase tracking-wider">debug log</p>
+        <button id="btn-clear-log" class="text-xs underline text-neutral-500 hover:text-neutral-800">clear log</button>
+      </div>
+      <pre id="log" class="text-xs whitespace-pre-wrap break-words max-h-56 overflow-auto bg-neutral-50 rounded-lg p-3"></pre>
+    </section>
+
     <section id="results" class="grid md:grid-cols-2 gap-4"></section>
   </main>
 
   <script type="module">
-    import removeBackground from "https://esm.sh/@imgly/background-removal@1.7.0";
-
     const el = {
       files: document.getElementById("inp-files"),
       type: document.getElementById("sel-type"),
@@ -86,14 +93,36 @@
       quality: document.getElementById("inp-quality"),
       run: document.getElementById("btn-run"),
       clear: document.getElementById("btn-clear"),
+      clearLog: document.getElementById("btn-clear-log"),
       status: document.getElementById("status"),
+      log: document.getElementById("log"),
       results: document.getElementById("results")
     };
 
     const objectUrls = new Set();
+    let removeBackgroundFn = null;
+    let loadingLibPromise = null;
+
+    const now = () => new Date().toLocaleTimeString();
+
+    const appendLog = (...args) => {
+      const line = `[${now()}] ${args.map((v) => {
+        if (v instanceof Error) return `${v.name}: ${v.message}`;
+        if (typeof v === "object") {
+          try { return JSON.stringify(v); } catch { return String(v); }
+        }
+        return String(v);
+      }).join(" ")}`;
+      console.log("[bg-test]", ...args);
+      if (el.log) {
+        el.log.textContent += (el.log.textContent ? "\n" : "") + line;
+        el.log.scrollTop = el.log.scrollHeight;
+      }
+    };
 
     const setStatus = (msg) => {
       el.status.textContent = msg || "";
+      appendLog("STATUS:", msg || "");
     };
 
     const clamp = (v, min, max) => Math.max(min, Math.min(max, v));
@@ -164,12 +193,14 @@
     const revokeAllUrls = () => {
       for (const url of objectUrls) URL.revokeObjectURL(url);
       objectUrls.clear();
+      appendLog("revoked object urls");
     };
 
     const clearResults = () => {
       revokeAllUrls();
       el.results.innerHTML = "";
-      setStatus("");
+      el.status.textContent = "";
+      appendLog("cleared results");
     };
 
     const setBusy = (busy) => {
@@ -178,10 +209,62 @@
       el.run.style.cursor = busy ? "not-allowed" : "pointer";
     };
 
+    async function loadLib() {
+      if (removeBackgroundFn) return removeBackgroundFn;
+      if (loadingLibPromise) return loadingLibPromise;
+
+      const urls = [
+        "https://esm.sh/@imgly/background-removal@1.7.0?bundle",
+        "https://cdn.jsdelivr.net/npm/@imgly/background-removal@1.7.0/+esm"
+      ];
+
+      loadingLibPromise = (async () => {
+        let lastErr = null;
+
+        for (const url of urls) {
+          try {
+            appendLog("trying import:", url);
+            const mod = await import(url);
+            const fn = mod?.default || mod?.removeBackground || mod?.imglyRemoveBackground;
+            if (typeof fn !== "function") {
+              throw new Error(`No usable remove function export. keys=${Object.keys(mod || {}).join(",")}`);
+            }
+            removeBackgroundFn = fn;
+            appendLog("library loaded from:", url);
+            return removeBackgroundFn;
+          } catch (err) {
+            lastErr = err;
+            appendLog("import failed:", url, err);
+          }
+        }
+
+        throw lastErr || new Error("Failed to load @imgly/background-removal from all CDNs.");
+      })();
+
+      return loadingLibPromise;
+    }
+
+    function formatErr(err) {
+      if (!err) return "Unknown error";
+      if (err instanceof Error) return `${err.name}: ${err.message}`;
+      try { return JSON.stringify(err); } catch { return String(err); }
+    }
+
     el.clear.addEventListener("click", clearResults);
+    el.clearLog.addEventListener("click", () => { el.log.textContent = ""; });
+
+    window.addEventListener("error", (e) => {
+      appendLog("window.error:", e.message || e.error || e);
+    });
+
+    window.addEventListener("unhandledrejection", (e) => {
+      appendLog("unhandledrejection:", formatErr(e.reason));
+    });
 
     el.run.addEventListener("click", async () => {
       const files = [...(el.files.files || [])];
+      appendLog("run clicked. files:", files.map(f => `${f.name} (${f.size} bytes)`));
+
       if (!files.length) {
         setStatus("pick at least one image first.");
         el.files.focus();
@@ -192,15 +275,20 @@
       setBusy(true);
 
       try {
+        setStatus("loading @imgly/background-removal...");
+        const removeBackground = await loadLib();
+
         const outputType = el.type.value;
         const outputFormat = el.format.value;
         const quality = clamp(Number.parseFloat(el.quality.value || "0.9") || 0.9, 0, 1);
+        appendLog("config:", { outputType, outputFormat, quality });
 
         for (let i = 0; i < files.length; i++) {
           const file = files[i];
           setStatus(`processing ${i + 1}/${files.length}: ${file.name} ...`);
 
           const config = {
+            debug: true,
             output: {
               type: outputType,
               format: outputFormat,
@@ -209,11 +297,15 @@
             progress: (key, current, total) => {
               if (!total) return;
               const pct = Math.round((current / total) * 100);
-              setStatus(`downloading model assets (${key}) ${pct}% — file ${i + 1}/${files.length}`);
+              el.status.textContent = `downloading model assets (${key}) ${pct}% — file ${i + 1}/${files.length}`;
             }
           };
 
+          appendLog("calling removeBackground for:", file.name);
+          const started = performance.now();
           const outBlob = await removeBackground(file, config);
+          const ms = Math.round(performance.now() - started);
+          appendLog("done:", file.name, `in ${ms}ms`, `blob=${outBlob.type} ${outBlob.size} bytes`);
 
           const originalUrl = URL.createObjectURL(file);
           const outputUrl = URL.createObjectURL(outBlob);
@@ -232,14 +324,17 @@
 
         setStatus(`done ✓ processed ${files.length} image${files.length > 1 ? "s" : ""}.`);
       } catch (err) {
+        const msg = formatErr(err);
         console.error(err);
-        setStatus(`error: ${err?.message || String(err)}`);
+        setStatus(`error: ${msg}`);
+        appendLog("FATAL:", msg, err?.stack || "");
       } finally {
         setBusy(false);
       }
     });
 
     window.addEventListener("beforeunload", revokeAllUrls);
+    appendLog("test page booted");
   </script>
 </body>
 </html>
