diff --git a/tests/test_url_validator.py b/tests/test_url_validator.py
new file mode 100644
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--- /dev/null
+++ b/tests/test_url_validator.py
@@ -0,0 +1,268 @@
+# tests/test_url_validator.py
+# Unit tests for src/utils/url_validator.py
+#
+# Run with:   python -m pytest tests/test_url_validator.py
+# Or:         python tests/test_url_validator.py
+
+import sys
+import os
+
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), ".."))
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "src"))
+
+from utils.url_validator import (
+    is_valid_url,
+    parse_resource,
+    validate_resource,
+    validate_resources,
+)
+
+
+# ---------------------------------------------------------------------------
+# is_valid_url — valid URLs
+# ---------------------------------------------------------------------------
+
+def test_valid_https_url():
+    assert is_valid_url("https://example.com") is True
+
+
+def test_valid_http_url():
+    assert is_valid_url("http://example.com") is True
+
+
+def test_valid_url_with_path():
+    assert is_valid_url("https://example.com/path/to/resource") is True
+
+
+def test_valid_url_with_query_string():
+    assert is_valid_url("https://example.com/search?q=python&lang=en") is True
+
+
+def test_valid_url_with_fragment():
+    assert is_valid_url("https://example.com/page#section") is True
+
+
+def test_valid_url_with_port():
+    assert is_valid_url("https://example.com:8443/path") is True
+
+
+def test_valid_url_localhost():
+    assert is_valid_url("http://localhost:5000/") is True
+
+
+def test_valid_url_case_insensitive_scheme():
+    assert is_valid_url("HTTPS://EXAMPLE.COM") is True
+    assert is_valid_url("HTTP://EXAMPLE.COM") is True
+
+
+def test_valid_url_subdomain():
+    assert is_valid_url("https://docs.example.com/guide") is True
+
+
+def test_valid_url_with_trailing_slash():
+    assert is_valid_url("https://example.com/") is True
+
+
+def test_valid_url_with_hyphen_in_domain():
+    assert is_valid_url("https://my-example.com/") is True
+
+
+# ---------------------------------------------------------------------------
+# is_valid_url — invalid URLs
+# ---------------------------------------------------------------------------
+
+def test_invalid_none():
+    assert is_valid_url(None) is False
+
+
+def test_invalid_empty_string():
+    assert is_valid_url("") is False
+
+
+def test_invalid_whitespace_only():
+    assert is_valid_url("   ") is False
+
+
+def test_invalid_non_string():
+    assert is_valid_url(123) is False
+    assert is_valid_url(["https://example.com"]) is False
+    assert is_valid_url(None) is False
+
+
+def test_invalid_ftp_scheme():
+    assert is_valid_url("ftp://example.com/file") is False
+
+
+def test_invalid_mailto():
+    assert is_valid_url("mailto:user@example.com") is False
+
+
+def test_invalid_bare_domain():
+    assert is_valid_url("example.com") is False
+
+
+def test_invalid_file_scheme():
+    assert is_valid_url("file:///etc/passwd") is False
+
+
+def test_invalid_relative_path():
+    assert is_valid_url("/path/to/resource") is False
+
+
+def test_invalid_url_with_trailing_whitespace():
+    # The validator strips whitespace, so this is valid
+    assert is_valid_url("https://example.com  ") is True
+    # But with leading whitespace only
+    assert is_valid_url("  https://example.com") is True
+
+
+# ---------------------------------------------------------------------------
+# parse_resource — labeled format
+# ---------------------------------------------------------------------------
+
+def test_parse_resource_with_label():
+    result = parse_resource("MDN Docs: https://developer.mozilla.org/")
+    assert result["label"] == "MDN Docs"
+    assert result["url"] == "https://developer.mozilla.org/"
+
+
+def test_parse_resource_with_label_extra_whitespace():
+    # Leading/trailing whitespace on the whole string is stripped.
+    # Two spaces between label and ':' breaks the ': http' split marker,
+    # so this is treated as a bare URL (documented edge case).
+    result = parse_resource("  MDN Docs  :  https://developer.mozilla.org/  ")
+    assert result["label"] == "MDN Docs  :  https://developer.mozilla.org/"
+    assert result["url"] == "MDN Docs  :  https://developer.mozilla.org/"
+
+
+def test_parse_resource_label_with_colon():
+    # The split marker is ": http", so a URL-only string starting with
+    # "http" is treated as a bare URL, not a label
+    result = parse_resource("Tutorial: https://example.com/tutorial?q=what")
+    assert result["label"] == "Tutorial"
+    assert result["url"] == "https://example.com/tutorial?q=what"
+
+
+# ---------------------------------------------------------------------------
+# parse_resource — bare URL format
+# ---------------------------------------------------------------------------
+
+def test_parse_resource_bare_https():
+    result = parse_resource("https://example.com")
+    assert result["label"] == "https://example.com"
+    assert result["url"] == "https://example.com"
+
+
+def test_parse_resource_bare_http():
+    result = parse_resource("http://example.com")
+    assert result["label"] == "http://example.com"
+    assert result["url"] == "http://example.com"
+
+
+def test_parse_resource_bare_url_with_path():
+    result = parse_resource("https://example.com/path/to/page")
+    assert result["url"] == "https://example.com/path/to/page"
+
+
+# ---------------------------------------------------------------------------
+# parse_resource — edge cases
+# ---------------------------------------------------------------------------
+
+def test_parse_resource_none():
+    result = parse_resource(None)
+    assert result == {"label": "", "url": ""}
+
+
+def test_parse_resource_empty_string():
+    result = parse_resource("")
+    assert result == {"label": "", "url": ""}
+
+
+def test_parse_resource_non_string():
+    result = parse_resource(123)
+    assert result == {"label": "", "url": ""}
+
+
+def test_parse_resource_colon_without_space():
+    # "Label:https://..." does not match ": http" split marker
+    result = parse_resource("Label:https://example.com")
+    assert result["url"] == "Label:https://example.com"
+    assert result["label"] == "Label:https://example.com"
+
+
+def test_parse_resource_whitespace_only():
+    result = parse_resource("   ")
+    assert result == {"label": "", "url": ""}
+
+
+# ---------------------------------------------------------------------------
+# validate_resource
+# ---------------------------------------------------------------------------
+
+def test_validate_resource_valid():
+    result = validate_resource("Docs: https://example.com/docs")
+    assert result["label"] == "Docs"
+    assert result["url"] == "https://example.com/docs"
+    assert result["valid"] is True
+
+
+def test_validate_resource_invalid_url():
+    result = validate_resource("Docs: not-a-valid-url")
+    assert result["label"] == "Docs"
+    assert result["url"] == "not-a-valid-url"
+    assert result["valid"] is False
+
+
+def test_validate_resource_bare_valid_url():
+    result = validate_resource("https://example.com")
+    assert result["valid"] is True
+
+
+def test_validate_resource_bare_invalid_url():
+    result = validate_resource("bare-domain.com")
+    assert result["valid"] is False
+
+
+# ---------------------------------------------------------------------------
+# validate_resources
+# ---------------------------------------------------------------------------
+
+def test_validate_resources_list_of_valid():
+    resources = [
+        "MDN: https://developer.mozilla.org/",
+        "https://docs.python.org/",
+    ]
+    results = validate_resources(resources)
+    assert len(results) == 2
+    assert all(r["valid"] for r in results)
+
+
+def test_validate_resources_mixed_valid_invalid():
+    resources = [
+        "Valid: https://example.com/",
+        "Invalid: ftp://example.com",
+    ]
+    results = validate_resources(resources)
+    assert len(results) == 2
+    assert results[0]["valid"] is True
+    assert results[1]["valid"] is False
+
+
+def test_validate_resources_empty_list():
+    results = validate_resources([])
+    assert results == []
+
+
+def test_validate_resources_not_a_list_returns_empty():
+    assert validate_resources("not a list") == []
+    assert validate_resources(None) == []
+    assert validate_resources(123) == []
+
+
+# ---------------------------------------------------------------------------
+# Run directly
+# ---------------------------------------------------------------------------
+
+if __name__ == "__main__":
+    import pytest
+    sys.exit(pytest.main([__file__, "-v", "--no-header"]))