diff --git a/bulkredditdownloader/download_filter.py b/bulkredditdownloader/download_filter.py
new file mode 100644
index 0000000..806fd0d
--- /dev/null
+++ b/bulkredditdownloader/download_filter.py
@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+# coding=utf-8
+
+import re
+
+
+class DownloadFilter:
+    def __init__(self, excluded_extensions: list[str] = None, excluded_domains: list[str] = None):
+        self.excluded_extensions = excluded_extensions
+        self.excluded_domains = excluded_domains
+
+    def check_url(self, url: str) -> bool:
+        """Return whether a URL is allowed or not"""
+        if not self._check_extension(url):
+            return False
+        elif not self._check_domain(url):
+            return False
+        else:
+            return True
+
+    def _check_extension(self, url: str) -> bool:
+        if not self.excluded_extensions:
+            return True
+        combined_extensions = '|'.join(self.excluded_extensions)
+        pattern = re.compile(r'.*({})$'.format(combined_extensions))
+        if re.match(pattern, url):
+            return False
+        else:
+            return True
+
+    def _check_domain(self, url: str) -> bool:
+        if not self.excluded_domains:
+            return True
+        combined_domains = '|'.join(self.excluded_domains)
+        pattern = re.compile(r'https?://.*({}).*'.format(combined_domains))
+        if re.match(pattern, url):
+            return False
+        else:
+            return True
diff --git a/bulkredditdownloader/tests/test_download_filter.py b/bulkredditdownloader/tests/test_download_filter.py
new file mode 100644
index 0000000..c8957a5
--- /dev/null
+++ b/bulkredditdownloader/tests/test_download_filter.py
@@ -0,0 +1,54 @@
+#!/usr/bin/env python3
+# coding=utf-8
+
+import pytest
+
+from bulkredditdownloader.download_filter import DownloadFilter
+
+
+@pytest.fixture()
+def download_filter() -> DownloadFilter:
+    return DownloadFilter(['mp4', 'mp3'], ['test.com', 'reddit.com'])
+
+
+@pytest.mark.parametrize(('test_url', 'expected'), (('test.mp4', False),
+                                                    ('test.avi', True),
+                                                    ('test.random.mp3', False)
+                                                    ))
+def test_filter_extension(test_url: str, expected: bool, download_filter: DownloadFilter):
+    result = download_filter._check_extension(test_url)
+    assert result == expected
+
+
+@pytest.mark.parametrize(('test_url', 'expected'), (('test.mp4', True),
+                                                    ('http://reddit.com/test.mp4', False),
+                                                    ('http://reddit.com/test.gif', False),
+                                                    ('https://www.example.com/test.mp4', True),
+                                                    ('https://www.example.com/test.png', True),
+                                                    ))
+def test_filter_domain(test_url: str, expected: bool, download_filter: DownloadFilter):
+    result = download_filter._check_domain(test_url)
+    assert result == expected
+
+
+@pytest.mark.parametrize(('test_url', 'expected'), (('test.mp4', False),
+                                                    ('test.gif', True),
+                                                    ('https://www.example.com/test.mp4', False),
+                                                    ('https://www.example.com/test.png', True),
+                                                    ('http://reddit.com/test.mp4', False),
+                                                    ('http://reddit.com/test.gif', False),
+                                                    ))
+def test_filter_all(test_url: str, expected: bool, download_filter: DownloadFilter):
+    result = download_filter.check_url(test_url)
+    assert result == expected
+
+
+@pytest.mark.parametrize('test_url', ('test.mp3',
+                                      'test.mp4',
+                                      'http://reddit.com/test.mp4',
+                                      't',
+                                      ))
+def test_filter_empty_filter(test_url: str):
+    download_filter = DownloadFilter()
+    result = download_filter.check_url(test_url)
+    assert result is True