diff --git a/test/external/external_test_simple_tokenizer.py b/test/external/external_test_simple_tokenizer.py
new file mode 100644
index 0000000000..b3e33e0d4d
--- /dev/null
+++ b/test/external/external_test_simple_tokenizer.py
@@ -0,0 +1,39 @@
+from transformers import AutoTokenizer
+from datasets import load_dataset
+from tinygrad.apps.llm import SimpleTokenizer
+from tinygrad.helpers import tqdm, getenv
+
+# use ALLOW_FAILED=-1 to go over the entire dataset without printing.
+if __name__ == "__main__":
+  base_tokenizer = AutoTokenizer.from_pretrained("NousResearch/Meta-Llama-3-8B-Instruct")
+  vocab_words = [ word for word, _ in sorted(base_tokenizer.get_vocab().items(), key=lambda t: t[1]) ]
+  inv_vocab = { tid: word for word, tid in base_tokenizer.get_vocab().items() }
+  simple_tokenizer = SimpleTokenizer(vocab_words)
+
+  color_codes = [ 91, 92, 94, 93, 95 ]
+  def color_tokens(tids): return "".join(f"\033[{color_codes[i%len(color_codes)]}m{inv_vocab[t]}" for i, t in enumerate(tids)) + "\033[0m"
+
+  ds = load_dataset("OpenAssistant/oasst1")
+  allow_failed = getenv("ALLOW_FAILED", 10)
+
+  fail_count, total = 0, 0
+
+  for idx, el in enumerate(tqdm(ds["train"])):
+    total += 1
+
+    try: simple_tokens = tuple(simple_tokenizer.encode(el["text"]))
+    except RuntimeError: simple_tokens = ()
+    base_tokens = tuple(base_tokenizer.encode(el["text"], add_special_tokens=False))
+
+    if simple_tokens != base_tokens:
+      fail_count += 1
+      allow_failed -= 1
+
+      if allow_failed >= 0:
+        print(f"tokens mismatch at index: {idx}.\n")
+
+        print("simple:  ", color_tokens(simple_tokens))
+        print("official:", color_tokens(base_tokens) + "\n")
+
+      if allow_failed == 0: break
+  print(f"{fail_count}/{total} samples are inconsistent with the official tokenizer.")