diff --git a/hashtheplanet/config/config.py b/hashtheplanet/config/config.py
index 3d1622c..0c85625 100644
--- a/hashtheplanet/config/config.py
+++ b/hashtheplanet/config/config.py
@@ -1,12 +1,20 @@
 """
 This module handles the config file.
 """
+from enum import Enum
 import json
 from typing import Dict, List
 
 from hashtheplanet.resources.git_resource import GitResource
 from hashtheplanet.resources.npm_resource import NpmResource
 
+class ConfigField(Enum):
+    """
+    This enum contains every field that can be found in the config file
+    """
+    TARGETS = "targets"
+    EXCLUDE_REGEX = "exclude_regex"
+
 class Config():
     """
     This class implements methods to manipulate the config file.
@@ -25,15 +33,15 @@ def parse(self, config_path: str):
         with open(config_path, "r", encoding="utf-8") as file_fp:
             self._config = json.load(file_fp)
 
-    def get_targets(self, resource_name: str) -> List[str]:
+    def get(self, resource_name: str, config_field: ConfigField):
         """
-        This methods returns the targets used by the given resource.
+        This methods returns a field content used by the given resource.
         """
-        module_info: Dict = self._config.get(resource_name)
+        field_content: Dict = self._config.get(resource_name)
 
-        if module_info is None:
-            return []
-        return module_info.get("targets")
+        if not config_field or not field_content:
+            return None
+        return field_content.get(config_field.value)
 
     def get_used_resources(self) -> List[str]:
         """
diff --git a/hashtheplanet/core/hashtheplanet.py b/hashtheplanet/core/hashtheplanet.py
index ba96a82..19519b1 100644
--- a/hashtheplanet/core/hashtheplanet.py
+++ b/hashtheplanet/core/hashtheplanet.py
@@ -15,7 +15,7 @@
 from sqlalchemy.orm import sessionmaker
 
 # project imports
-from hashtheplanet.config.config import Config
+from hashtheplanet.config.config import Config, ConfigField
 from hashtheplanet.executor.executor import Executor
 from hashtheplanet.sql.db_connector import Base, DbConnector, Hash
 
@@ -90,10 +90,11 @@ def compute_hashs(self):
             self._config.parse(self._input_file)
 
             for resource_name in self._config.get_used_resources():
-                targets = self._config.get_targets(resource_name)
+                targets = self._config.get(resource_name, ConfigField.TARGETS) or []
+                exclude_regex = self._config.get(resource_name, ConfigField.EXCLUDE_REGEX)
 
                 for target in targets:
-                    self._executor.execute(resource_name, target)
+                    self._executor.execute(resource_name, target, exclude_regex)
 
             logger.info("Computing done")
 
diff --git a/hashtheplanet/executor/executor.py b/hashtheplanet/executor/executor.py
index 3cba013..a30c98a 100644
--- a/hashtheplanet/executor/executor.py
+++ b/hashtheplanet/executor/executor.py
@@ -2,6 +2,7 @@
 This module handles the resource executions.
 """
 from importlib import import_module
+from typing import Optional
 
 from loguru import logger
 
@@ -17,7 +18,7 @@ def __init__(self, database: DbConnector, session_scope):
         self._database = database
         self._session_scope = session_scope
 
-    def execute(self, resource_name: str, target: str):
+    def execute(self, resource_name: str, target: str, exclude_regex: Optional[str] = None):
         """
         This method executes a resource to compute hashes.
         """
@@ -31,4 +32,4 @@ def execute(self, resource_name: str, target: str):
             return
 
         resource_instance: Resource = getattr(module, resource_class_name)(self._database)
-        resource_instance.compute_hashes(self._session_scope, target)
+        resource_instance.compute_hashes(self._session_scope, target, exclude_regex)
diff --git a/hashtheplanet/resources/git_resource.py b/hashtheplanet/resources/git_resource.py
index 0faaf08..ade765f 100644
--- a/hashtheplanet/resources/git_resource.py
+++ b/hashtheplanet/resources/git_resource.py
@@ -6,7 +6,7 @@
 import subprocess
 import tempfile
 from stat import S_ISDIR, S_ISREG
-from typing import List, Tuple
+from typing import List, Optional, Tuple
 
 # third party imports
 from git import GitCommandError, Repo
@@ -54,10 +54,11 @@ def get_all_files_from_commit(commit: Commit) -> List[Tuple[FilePath, BlobHash]]
             file_list.append((blob.path, blob.hexsha))
         return file_list
 
-    @staticmethod
     def _hash_files(
+        self,
         files: List[GitFileMetadata],
-        repo_dir_path: str
+        repo_dir_path: str,
+        exclude_regex: Optional[str]
     ) -> List[FileMetadata]:
         """
         This method calculates the SHA256 hashes of input files.
@@ -69,6 +70,8 @@ def _hash_files(
         os.chdir(repo_dir_path)
 
         for (file_path, tag_name, blob_hash) in files:
+            if not self.should_save(exclude_regex, file_path):
+                continue
             try:
                 # We need to use a subprocess and not the GitPython library
                 # because when we execute "git cat-file -p [blob]" with it, it always removes the \n from the last line.
@@ -192,7 +195,7 @@ def _filter_stored_tags(stored_versions: List[VersionTable], found_tags: List[Ta
                 result.append(found_tag)
         return result
 
-    def compute_hashes(self, session_scope, target: str):
+    def compute_hashes(self, session_scope, target: str, exclude_regex: Optional[str]):
         """
         This method clones the repository from url, retrieves tags, compares each tags to retrieve only modified files,
         computes their hashes and then stores the tags & files information in the database.
@@ -203,6 +206,7 @@ def compute_hashes(self, session_scope, target: str):
 
         with tempfile.TemporaryDirectory() as tmp_dir_name:
             try:
+                logger.info(f"Cloning {target}")
                 repo = self.clone_repository(target, tmp_dir_name)
             except GitCommandError as error:
                 logger.warning(f"Error while cloning repository on {target}: {error}")
@@ -225,7 +229,7 @@ def compute_hashes(self, session_scope, target: str):
             files += self._get_diff_files(tags)
 
             logger.info("Generating hashes ...")
-            files_info = self._hash_files(files, tmp_dir_name)
+            files_info = self._hash_files(files, tmp_dir_name, exclude_regex)
 
         logger.info("Saving hashes ...")
         self._save_hashes(session_scope, files_info, tags, technology)
diff --git a/hashtheplanet/resources/npm_resource.py b/hashtheplanet/resources/npm_resource.py
index 8c301fc..3f2f475 100644
--- a/hashtheplanet/resources/npm_resource.py
+++ b/hashtheplanet/resources/npm_resource.py
@@ -4,7 +4,7 @@
 #standard imports
 import tarfile
 import tempfile
-from typing import Dict, List, Set, Tuple
+from typing import Dict, List, Optional, Set, Tuple
 import requests
 
 # third party imports
@@ -61,8 +61,7 @@ def save_tar_to_disk(file_path: str, npm_module_name: str, version: str):
         with open(file_path, 'wb') as file_fd:
             file_fd.write(request.content)
 
-    @staticmethod
-    def extract_hashes_from_tar(file_path: str) -> List[FileMetadata]:
+    def extract_hashes_from_tar(self, file_path: str, exclude_regex: Optional[str]) -> List[FileMetadata]:
         """
         This method returns all hashes of all files contained in a tar file.
         """
@@ -72,7 +71,7 @@ def extract_hashes_from_tar(file_path: str) -> List[FileMetadata]:
             for member in tar.getmembers():
                 file = tar.extractfile(member)
 
-                if file is None:
+                if file is None or not self.should_save(exclude_regex, member.path):
                     continue
                 files.append((member.path, Hash.hash_bytes(file.read())))
         return files
@@ -94,7 +93,7 @@ def _save_hashes(
                     self._database.insert_file(session, npm_module_name, file_path)
                     self._database.insert_or_update_hash(session, file_hash, npm_module_name, [version])
 
-    def compute_hashes(self, session_scope, target: str):
+    def compute_hashes(self, session_scope, target: str, exclude_regex: Optional[str]):
         """
         This method downloads all versions of an npm module and stores all the versions with their associated files
         and hashes and stores them in the database.
@@ -108,6 +107,6 @@ def compute_hashes(self, session_scope, target: str):
                 file_path = f"{tmp_dir_name}/{target}-{version}.tgz"
 
                 self.save_tar_to_disk(file_path, target, version)
-                files_info[version] = self.extract_hashes_from_tar(file_path)
+                files_info[version] = self.extract_hashes_from_tar(file_path, exclude_regex)
 
         self._save_hashes(session_scope, files_info, versions, target)
diff --git a/hashtheplanet/resources/resource.py b/hashtheplanet/resources/resource.py
index 644e266..e01bfe3 100644
--- a/hashtheplanet/resources/resource.py
+++ b/hashtheplanet/resources/resource.py
@@ -1,6 +1,9 @@
 """
 This module contains the base class for the resources.
 """
+import re
+from typing import Optional
+
 from hashtheplanet.sql.db_connector import DbConnector
 
 class Resource(): # pylint: disable=too-few-public-methods
@@ -12,8 +15,19 @@ class Resource(): # pylint: disable=too-few-public-methods
     def __init__(self, database: DbConnector):
         self._database = database
 
-    def compute_hashes(self, session_scope, target: str):
+    def compute_hashes(self, session_scope, target: str, exclude_regex: Optional[str]):
         """
         This method computes all the versions and their associated files & hashes and stores them in the database.
         """
         raise NotImplementedError()
+
+    @staticmethod
+    def should_save(exclude_regex: str, file_path: str):
+        """
+        This method permits to verify if the specified file should be saved in the database or not
+        """
+        if not file_path:
+            return False
+        if not exclude_regex:
+            return True
+        return not re.search(exclude_regex, file_path)
diff --git a/src/tech_list.json b/src/tech_list.json
index 1ee0d7d..75547d9 100644
--- a/src/tech_list.json
+++ b/src/tech_list.json
@@ -7,12 +7,14 @@
             "https://github.com/drupal/drupal.git",
             "https://github.com/magento/magento2.git",
             "https://github.com/joomla/joomla-cms.git"
-        ]
+        ],
+        "exclude_regex": "\\.php|tests\\/|test\\/|\\.gitignore|\\.package|\\.idea|qunit|\\.editorconfig|vendor\\/|\\.vue|\\.scss|\\.less"
     },
     "npm": {
         "targets": [
             "underscore",
             "jquery"
-        ]
+        ],
+        "exclude_regex": "tests\\/|test\\/|\\.jshintrc|\\.npmignore|\\.bowerrc|\\.jscsrc|\\.bower.json|\\.eslintrc.json|\\.jshintignore|\\.eslintrc|\\.scss|\\.less|\\.vue|\\.scss|\\.less|\\.idea"
     }
 }
diff --git a/tests/config/test_config.py b/tests/config/test_config.py
index e74ad04..8e4e0c8 100644
--- a/tests/config/test_config.py
+++ b/tests/config/test_config.py
@@ -8,7 +8,7 @@
 from unittest.mock import MagicMock, mock_open, patch
 
 # project imports
-from hashtheplanet.config.config import Config
+from hashtheplanet.config.config import Config, ConfigField
 
 def get_mock_open(files: Dict[str, str]):
     def open_mock(filename, *args, **kwargs):
@@ -61,9 +61,9 @@ def test_get_targets():
     config = Config()
 
     with patch.dict(config._config, {"git": {"targets": ["target1", "target2"]}}):
-        assert len(config.get_targets("git")) == 2
+        assert len(config.get("git", ConfigField.TARGETS)) == 2
 
-        assert len(config.get_targets("npm")) == 0
+        assert not config.get("npm", ConfigField.TARGETS)
 
 def test_get_used_resources():
     config = Config()
diff --git a/tests/resources/test_git_resource.py b/tests/resources/test_git_resource.py
index d270faa..712dccb 100644
--- a/tests/resources/test_git_resource.py
+++ b/tests/resources/test_git_resource.py
@@ -91,10 +91,11 @@ def test_hash_files():
 
     git_resource = GitResource(None)
 
+    # when there are no excluded files
     with mock.patch("subprocess.check_output", subprocess_mock(blobs)) as sp_mock, \
         mock.patch("os.getcwd", return_value="/foobar/") as getcwd_mock, \
         mock.patch("os.chdir", return_value=None) as chdir_mock:
-        files_metadata = git_resource._hash_files(git_files_metadata, "repo_dir_path")
+        files_metadata = git_resource._hash_files(git_files_metadata, "repo_dir_path", None)
 
         assert sp_mock.call_count == 3
         sp_mock.assert_called_with(['git', 'cat-file', '-p', 'e42f952edc48e2c085c206166bf4f1ead4d4b058'], shell=False)
@@ -114,11 +115,31 @@ def test_hash_files():
         assert files_metadata[1][1] == "1.2.5"
         assert files_metadata[1][2] == hashlib.sha256(blobs.get("e42f952edc48e2c085c206166bf4f1ead4d4b058")).hexdigest()
 
+    git_resource = GitResource(None)
+
+    # When the *.cfg files are excluded
+    with mock.patch("subprocess.check_output", subprocess_mock(blobs)) as sp_mock, \
+        mock.patch("os.getcwd", return_value="/foobar/") as getcwd_mock, \
+        mock.patch("os.chdir", return_value=None) as chdir_mock:
+        files_metadata = git_resource._hash_files(git_files_metadata, "repo_dir_path", "\\.cfg$")
+
+        assert sp_mock.call_count == 2
+
+        getcwd_mock.assert_called_once()
+
+        assert chdir_mock.call_count == 2
+        chdir_mock.assert_called_with("/foobar/")
+
+        assert len(files_metadata) == 1
+
+        assert files_metadata[0][0] == "LICENSE"
+        assert files_metadata[0][1] == "1.2.3"
+        assert files_metadata[0][2] == hashlib.sha256(blobs.get("d159169d1050894d3ea3b98e1c965c4058208fe1")).hexdigest()
 
     with mock.patch("subprocess.check_output", subprocess_mock(blobs)) as sp_mock, \
         mock.patch("os.getcwd", return_value="/foobar/") as getcwd_mock, \
         mock.patch("os.chdir", return_value=None) as chdir_mock:
-        files_metadata = git_resource._hash_files([["empty", "1.2.1", "empty"]], "repo_dir_path")
+        files_metadata = git_resource._hash_files([["empty", "1.2.1", "empty"]], "repo_dir_path", None)
 
         assert sp_mock.call_count == 1
         sp_mock.assert_called_with(['git', 'cat-file', '-p', 'empty'], shell=False)
@@ -134,7 +155,7 @@ def test_hash_files():
     with mock.patch.object(subprocess, "check_output", MagicMock(side_effect=ValueError("error"))) as mock_exec, \
         mock.patch("os.getcwd", return_value="/foobar/") as getcwd_mock, \
         mock.patch("os.chdir", return_value=None) as chdir_mock:
-        git_resource._hash_files(git_files_metadata, "repo_dir_path")
+        git_resource._hash_files(git_files_metadata, "repo_dir_path", None)
 
         getcwd_mock.assert_called_once()
 
@@ -411,7 +432,7 @@ def mock_tmp_dir():
         session = MagicMock()
         git_resource = GitResource(DbConnector())
 
-        git_resource.compute_hashes(session, repo_url)
+        git_resource.compute_hashes(session, repo_url, None)
 
         # In this situation, we verify that by giving a good repo_url & a good tmp_dir_path
         # we download the tags, calculate hash & store them in the database
@@ -420,7 +441,7 @@ def mock_tmp_dir():
         mock_get_tag_files.assert_called_once_with(tags[0])
         mock_filter_stored_tags.assert_called_once_with([], tags)
         mock_get_diff_files.assert_called_once_with(tags)
-        mock_hash_files.assert_called_once_with([1, 2], tmp_dir_path)
+        mock_hash_files.assert_called_once_with([1, 2], tmp_dir_path, None)
         mock_save_hashes.assert_called_once_with(session, "hashed files", tags, "foobar")
 
     with patch.object(
@@ -435,7 +456,7 @@ def mock_tmp_dir():
     patch.object(GitResource, "_hash_files", return_value="hashed files") as mock_hash_files, \
     patch.object(GitResource, "_save_hashes") as mock_save_hashes, \
     patch.object(DbConnector, "get_versions") as mock_get_versions:
-        git_resource.compute_hashes(MagicMock(), repo_url)
+        git_resource.compute_hashes(MagicMock(), repo_url, None)
         mock_clone_repo.assert_called_once_with(repo_url, tmp_dir_path)
 
         # In this situation, we verify that by giving a wrong repository we stop the function
diff --git a/tests/resources/test_npm_resource.py b/tests/resources/test_npm_resource.py
index 32fe2fb..d1fd6cb 100644
--- a/tests/resources/test_npm_resource.py
+++ b/tests/resources/test_npm_resource.py
@@ -72,7 +72,7 @@ def mocked_get_request(url: str, *args, **kwargs):
 
 def test_extract_hashes_from_tar():
     path = "./test.tgz"
-    members = ["a", "b", None, "c"]
+    members = ["a", "b.txt", None, "c"]
 
     class MockedTarMember():
         def __init__(self, member) -> None:
@@ -105,10 +105,11 @@ def mocked_open_tar(file_path: str) -> MockedTarFile:
         assert file_path == path
         return MockedTarFile()
 
+    # when there are no excluded files
     with mock.patch("tarfile.open", MagicMock(side_effect=mocked_open_tar)) as mock_open_tar:
         npm_resource = NpmResource(MagicMock())
 
-        files = npm_resource.extract_hashes_from_tar(path)
+        files = npm_resource.extract_hashes_from_tar(path, None)
         assert mock_open_tar.called is True
         assert mock_open_tar.call_count == 1
 
@@ -117,12 +118,27 @@ def mocked_open_tar(file_path: str) -> MockedTarFile:
         assert files[0][0] == "a"
         assert files[0][1] == hashlib.sha256("a".encode("utf-8")).hexdigest()
 
-        assert files[1][0] == "b"
-        assert files[1][1] == hashlib.sha256("b".encode("utf-8")).hexdigest()
+        assert files[1][0] == "b.txt"
+        assert files[1][1] == hashlib.sha256("b.txt".encode("utf-8")).hexdigest()
 
         assert files[2][0] == "c"
         assert files[2][1] == hashlib.sha256("c".encode("utf-8")).hexdigest()
 
+    # When the *.txt files are excluded
+    with mock.patch("tarfile.open", MagicMock(side_effect=mocked_open_tar)) as mock_open_tar:
+        npm_resource = NpmResource(MagicMock())
+
+        files = npm_resource.extract_hashes_from_tar(path, "\\.txt$")
+        assert mock_open_tar.called is True
+        assert mock_open_tar.call_count == 1
+
+        assert len(files) == 2
+
+        assert files[0][0] == "a"
+        assert files[0][1] == hashlib.sha256("a".encode("utf-8")).hexdigest()
+
+        assert files[1][0] == "c"
+        assert files[1][1] == hashlib.sha256("c".encode("utf-8")).hexdigest()
 
 def test_save_hashes():
     npm_module_name = "test"
@@ -174,7 +190,7 @@ def __exit__(self, *args):
     def mock_tmp_dir():
         return MockDir()
 
-    def mock_extract_hashes_from_tar(file_path: str):
+    def mock_extract_hashes_from_tar(file_path: str, exclude_regex: str):
         if file_path == f"{tmp_dir_path}/{target}-1.2.3.tgz":
             return files_info["1.2.3"]
         elif file_path == f"{tmp_dir_path}/{target}-1.2.4.tgz":
@@ -190,7 +206,7 @@ def mock_extract_hashes_from_tar(file_path: str):
         mock.patch("tempfile.TemporaryDirectory", MagicMock(side_effect=mock_tmp_dir)):
         npm_resource = NpmResource(MagicMock())
         session = MagicMock()
-        npm_resource.compute_hashes(session, target)
+        npm_resource.compute_hashes(session, target, None)
 
         mock_versions.assert_called_once()
         mock_tar.call_count == 2
diff --git a/tests/resources/test_resource.py b/tests/resources/test_resource.py
index 5f12086..ba63618 100644
--- a/tests/resources/test_resource.py
+++ b/tests/resources/test_resource.py
@@ -17,7 +17,21 @@ def test_compute_hashes():
     resource = Resource("database")
 
     try:
-        resource.compute_hashes(None, None)
+        resource.compute_hashes(None, None, None)
         assert False
     except NotImplementedError as error:
         assert True
+
+def test_should_save():
+    resource = Resource("test")
+
+    assert resource.should_save(".php", "test.php") is False
+    assert resource.should_save(".js", "test.php") is True
+    assert resource.should_save("^tests/", "tests/foobar.js") is False
+
+def test_should_save_none():
+    resource = Resource("test")
+
+    assert resource.should_save(None, "test.php") is True
+    assert resource.should_save(".js", None) is False
+    assert resource.should_save(None, None) is False