diff --git a/.gitignore b/.gitignore
index bee8a64..5542df6 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1 +1,6 @@
 __pycache__
+# Ignore the extracted ISO 639-3 code tables directory and its zip archive.
+# These files are likely large data resources not needed in version control.
+iso-639-3_Code_Tables_20240415/
+iso-639-3_Code_Tables_20240415.zip
+
diff --git a/Makefile b/Makefile
index d296424..b6bfe9e 100644
--- a/Makefile
+++ b/Makefile
@@ -4,9 +4,13 @@ init:
 get-table:
 	# https://iso639-3.sil.org/code_tables/download_tables
 	wget https://iso639-3.sil.org/sites/iso639-3/files/downloads/iso-639-3_Code_Tables_20240415.zip
+	unzip -o iso-639-3_Code_Tables_20240415.zip
 
 combine-wikipedia:
 	cat wikipedia_languages.csv  wikipedia_languages_extra.csv > wikipedia_languages_all.csv
 
 generate:
-	python generate.py
+	python3 generate.py
+
+validate:
+    python3 validate_output.py
diff --git a/requirements.txt b/requirements.txt
index dffbfe9..c7f9a31 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -2,3 +2,4 @@ beautifulsoup4
 jinja2
 lxml
 pyarrow
+pytest
\ No newline at end of file
diff --git a/test_validate_output.py b/test_validate_output.py
new file mode 100644
index 0000000..25b169e
--- /dev/null
+++ b/test_validate_output.py
@@ -0,0 +1,20 @@
+from validate_output import validate_markdown_file
+import os
+
+def test_missing_title(tmp_path):
+    test_file = tmp_path / "test1.md"
+    test_file.write_text("Summary: This is a test.")
+    errors = validate_markdown_file(str(test_file))
+    assert "Missing title" in errors
+
+def test_missing_summary(tmp_path):
+    test_file = tmp_path / "test2.md"
+    test_file.write_text("# Test Title")
+    errors = validate_markdown_file(str(test_file))
+    assert "Missing summary section" in errors
+
+def test_valid_markdown(tmp_path):
+    test_file = tmp_path / "test3.md"
+    test_file.write_text("# Test Title\nSummary: All good.")
+    errors = validate_markdown_file(str(test_file))
+    assert not errors
\ No newline at end of file
diff --git a/validate_output.py b/validate_output.py
new file mode 100644
index 0000000..b4b4ac3
--- /dev/null
+++ b/validate_output.py
@@ -0,0 +1,44 @@
+import sys
+import os
+import re
+
+def validate_markdown_file(filepath):
+    with open(filepath, 'r', encoding='utf-8') as f:
+        content = f.read()
+    errors = []
+    if not re.search(r'^# ', content, re.MULTILINE):
+        errors.append("Missing title")
+    if "Summary:" not in content:
+        errors.append("Missing summary section")
+    return errors
+
+def validate_directory(output_dir):
+    failed = False
+    for fname in os.listdir(output_dir):
+        if fname.endswith('.md'):
+            errors = validate_markdown_file(os.path.join(output_dir, fname))
+            if errors:
+                failed = True
+                print(f"{os.path.join(output_dir, fname)}:")
+                for err in errors:
+                    print(f"  - {err}")
+    return failed
+
+def main():
+    base_dir = sys.argv[1] if len(sys.argv) > 1 else "../web-languages"
+    failed = False
+    if os.path.isdir(base_dir):
+        # Validate all subdirectories
+        for subdir in os.listdir(base_dir):
+            full_path = os.path.join(base_dir, subdir)
+            if os.path.isdir(full_path):
+                if validate_directory(full_path):
+                    failed = True
+    else:
+        print(f"Error: Directory '{base_dir}' does not exist.")
+        sys.exit(1)
+    if failed:
+        sys.exit(1)
+
+if __name__ == "__main__":
+    main()
\ No newline at end of file