diff --git a/passifypdf/cli.py b/passifypdf/cli.py
index 7364188..ddb9c65 100644
--- a/passifypdf/cli.py
+++ b/passifypdf/cli.py
@@ -1,13 +1,102 @@
-import argparse
-
-
-def get_arg_parser() -> argparse.ArgumentParser:
-    arg_parser = argparse.ArgumentParser(
-        description="Encrypt a PDF file with a password of your choice.",
-        epilog="For more information, visit: https://github.com/SUPAIDEAS/passifypdf"
-    )
-    arg_parser.add_argument("-v", "--version", action="version", version="%(prog)s 1.0")
-    arg_parser.add_argument("-i", "--input", required=True, help="Path to the input PDF file to be encrypted")
-    arg_parser.add_argument("-o", "--output", required=True, help="Path where the encrypted PDF file will be saved")
-    arg_parser.add_argument("-p", "--passwd", required=True, type=str, help="Password to encrypt the PDF file with")
-    return arg_parser
\ No newline at end of file
+"""CLI module using Typer for the passifypdf tool."""
+
+import logging
+from importlib.metadata import PackageNotFoundError, version
+from pathlib import Path
+
+import typer
+from typing_extensions import Annotated
+
+from passifypdf.encryptpdf import encrypt_pdf
+
+logger = logging.getLogger(__name__)
+
+try:
+    __version__ = version("passifypdf")
+except PackageNotFoundError:
+    __version__ = "unknown"
+
+app = typer.Typer(
+    name="passifypdf",
+    help="Encrypt a PDF file with a password of your choice.",
+    epilog="For more information, visit: https://github.com/SUPAIDEAS/passifypdf",
+    add_completion=False,
+)
+
+
+def version_callback(value: bool) -> None:
+    """Print the version and exit."""
+    if value:
+        typer.echo(f"passifypdf {__version__}")
+        raise typer.Exit()
+
+
+@app.command()
+def encrypt(
+    input: Annotated[
+        Path,
+        typer.Option(
+            "--input", "-i",
+            help="Path to the input PDF file to be encrypted.",
+            exists=True,
+            file_okay=True,
+            dir_okay=False,
+            readable=True,
+        ),
+    ],
+    output: Annotated[
+        Path,
+        typer.Option(
+            "--output", "-o",
+            help="Path where the encrypted PDF file will be saved.",
+        ),
+    ],
+    passwd: Annotated[
+        str,
+        typer.Option(
+            "--passwd", "-p",
+            help="Password to encrypt the PDF file with.",
+        ),
+    ],
+    force: Annotated[
+        bool,
+        typer.Option(
+            "--force", "-f",
+            help="Overwrite the output file if it already exists without prompting.",
+        ),
+    ] = False,
+    version: Annotated[
+        bool,
+        typer.Option(
+            "--version", "-v",
+            help="Show the version and exit.",
+            callback=version_callback,
+            is_eager=True,
+        ),
+    ] = False,
+) -> None:
+    """Encrypt a PDF file with a password of your choice."""
+
+    if output.exists() and not force:
+        overwrite = typer.confirm(
+            f"File '{output}' already exists. Overwrite?",
+            default=False,
+        )
+        if not overwrite:
+            logger.info("Operation cancelled.")
+            raise typer.Exit()
+
+    try:
+        encrypt_pdf(input, output, passwd)
+        logger.info(
+            "Congratulations!\nPDF file encrypted successfully and saved as '%s'",
+            output,
+        )
+    except Exception as e:
+        logger.error("Error: %s", e)
+        raise typer.Exit(code=1)
+
+
+def get_typer_app() -> typer.Typer:
+    """Return the configured Typer application instance."""
+    return app
\ No newline at end of file
diff --git a/passifypdf/encryptpdf.py b/passifypdf/encryptpdf.py
index e326cab..12509d1 100644
--- a/passifypdf/encryptpdf.py
+++ b/passifypdf/encryptpdf.py
@@ -6,8 +6,6 @@
 
 from pypdf import PdfReader, PdfWriter
 
-from .cli import get_arg_parser
-
 
 def encrypt_pdf(input_pdf: Union[str, Path], output_pdf: Union[str, Path], password: str) -> None:
     """
@@ -49,24 +47,11 @@ def encrypt_pdf(input_pdf: Union[str, Path], output_pdf: Union[str, Path], passw
         raise Exception(f"Failed to encrypt PDF: {e}")
 
 
-def main() -> int:
-    """
-    Main function to run the CLI.
-
-    Returns:
-        int: Exit code (0 for success, 1 for failure).
-    """
-    arg_parser = get_arg_parser()
-    args = arg_parser.parse_args()
-
-    try:
-        encrypt_pdf(args.input, args.output, args.passwd)
-        print(f"Congratulations!\nPDF file encrypted successfully and saved as '{args.output}'")
-        return 0
-    except Exception as e:
-        print(f"Error: {e}", file=sys.stderr)
-        return 1
+def main() -> None:
+    """Entry point: delegates to the Typer CLI application."""
+    from passifypdf.cli import app
+    app()
 
 
 if __name__ == "__main__":
-    sys.exit(main())
\ No newline at end of file
+    main()
\ No newline at end of file
diff --git a/pyproject.toml b/pyproject.toml
index 0aa8348..f945686 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -9,6 +9,8 @@ packages = [{include = "passifypdf"}]
 [tool.poetry.dependencies]
 python = "^3.8"
 pypdf = "^4.3.1"
+typer = {extras = ["standard"], version = "^0.12.0"}
+typing-extensions = "^4.0"
 
 [tool.poetry.group.dev.dependencies]
 coverage = "^7.0"
diff --git a/tests/unittests/test_cli.py b/tests/unittests/test_cli.py
new file mode 100644
index 0000000..bfed58c
--- /dev/null
+++ b/tests/unittests/test_cli.py
@@ -0,0 +1,186 @@
+"""Unit tests for the Typer-based CLI module."""
+
+from pathlib import Path
+from typing import Generator
+from unittest import TestCase
+from unittest.mock import MagicMock, patch
+
+from typer.testing import CliRunner
+
+from passifypdf.cli import app
+
+
+class TestTyperCli(TestCase):
+    """Tests for the Typer CLI application."""
+
+    def setUp(self) -> None:
+        """Set up test fixtures."""
+        self.runner = CliRunner()
+
+    # ------------------------------------------------------------------
+    # --help
+    # ------------------------------------------------------------------
+
+    def test_help_flag(self) -> None:
+        """Test that --help exits 0 and mentions key options."""
+        result = self.runner.invoke(app, ["--help"])
+        self.assertEqual(result.exit_code, 0)
+        self.assertIn("--input", result.output)
+        self.assertIn("--output", result.output)
+        self.assertIn("--passwd", result.output)
+
+    # ------------------------------------------------------------------
+    # --version
+    # ------------------------------------------------------------------
+
+    def test_version_flag(self) -> None:
+        """Test that --version exits 0 and prints the version."""
+        result = self.runner.invoke(app, ["--version"])
+        self.assertEqual(result.exit_code, 0)
+        self.assertIn("passifypdf", result.output)
+
+    # ------------------------------------------------------------------
+    # Happy path
+    # ------------------------------------------------------------------
+
+    @patch("passifypdf.cli.encrypt_pdf")
+    def test_encrypt_success(self, mock_encrypt: MagicMock) -> None:
+        """Test a successful encryption invocation."""
+        with self.runner.isolated_filesystem():
+            # Create a dummy input file so Typer's `exists=True` check passes
+            Path("input.pdf").write_bytes(b"%PDF-1.4 dummy")
+            result = self.runner.invoke(
+                app,
+                [
+                    "--input", "input.pdf",
+                    "--output", "output.pdf",
+                    "--passwd", "secret",
+                    "--force",
+                ],
+            )
+        self.assertEqual(result.exit_code, 0)
+        mock_encrypt.assert_called_once()
+
+    # ------------------------------------------------------------------
+    # Output collision — --force bypasses prompt
+    # ------------------------------------------------------------------
+
+    @patch("passifypdf.cli.encrypt_pdf")
+    def test_force_flag_skips_prompt(self, mock_encrypt: MagicMock) -> None:
+        """--force skips the overwrite prompt when output already exists."""
+        with self.runner.isolated_filesystem():
+            Path("input.pdf").write_bytes(b"%PDF-1.4 dummy")
+            Path("output.pdf").write_bytes(b"existing")
+            result = self.runner.invoke(
+                app,
+                [
+                    "--input", "input.pdf",
+                    "--output", "output.pdf",
+                    "--passwd", "secret",
+                    "--force",
+                ],
+            )
+        self.assertEqual(result.exit_code, 0)
+        mock_encrypt.assert_called_once()
+
+    # ------------------------------------------------------------------
+    # Output collision — user says no
+    # ------------------------------------------------------------------
+
+    @patch("passifypdf.cli.encrypt_pdf")
+    def test_no_force_user_declines(self, mock_encrypt: MagicMock) -> None:
+        """Without --force, declining the prompt should cancel the operation."""
+        with self.runner.isolated_filesystem():
+            Path("input.pdf").write_bytes(b"%PDF-1.4 dummy")
+            Path("output.pdf").write_bytes(b"existing")
+            # Provide 'n' as user input to the prompt
+            result = self.runner.invoke(
+                app,
+                [
+                    "--input", "input.pdf",
+                    "--output", "output.pdf",
+                    "--passwd", "secret",
+                ],
+                input="n\n",
+            )
+        self.assertEqual(result.exit_code, 0)
+        mock_encrypt.assert_not_called()
+
+    # ------------------------------------------------------------------
+    # Output collision — user says yes
+    # ------------------------------------------------------------------
+
+    @patch("passifypdf.cli.encrypt_pdf")
+    def test_no_force_user_accepts(self, mock_encrypt: MagicMock) -> None:
+        """Without --force, accepting the prompt should proceed with encryption."""
+        with self.runner.isolated_filesystem():
+            Path("input.pdf").write_bytes(b"%PDF-1.4 dummy")
+            Path("output.pdf").write_bytes(b"existing")
+            result = self.runner.invoke(
+                app,
+                [
+                    "--input", "input.pdf",
+                    "--output", "output.pdf",
+                    "--passwd", "secret",
+                ],
+                input="y\n",
+            )
+        self.assertEqual(result.exit_code, 0)
+        mock_encrypt.assert_called_once()
+
+    # ------------------------------------------------------------------
+    # Missing required options
+    # ------------------------------------------------------------------
+
+    def test_missing_required_options(self) -> None:
+        """Omitting required options should exit with a non-zero code."""
+        result = self.runner.invoke(app, [])
+        self.assertNotEqual(result.exit_code, 0)
+
+    # ------------------------------------------------------------------
+    # Non-existent input file
+    # ------------------------------------------------------------------
+
+    def test_input_file_not_found(self) -> None:
+        """Passing a non-existent input file should exit with an error."""
+        with self.runner.isolated_filesystem():
+            result = self.runner.invoke(
+                app,
+                [
+                    "--input", "ghost.pdf",
+                    "--output", "output.pdf",
+                    "--passwd", "secret",
+                ],
+            )
+        self.assertNotEqual(result.exit_code, 0)
+
+    # ------------------------------------------------------------------
+    # encrypt_pdf raises an error
+    # ------------------------------------------------------------------
+
+    @patch("passifypdf.cli.encrypt_pdf")
+    def test_encrypt_failure_exits_with_1(self, mock_encrypt: MagicMock) -> None:
+        """If encrypt_pdf raises an exception, CLI should exit with code 1."""
+        mock_encrypt.side_effect = Exception("boom")
+        with self.runner.isolated_filesystem():
+            Path("input.pdf").write_bytes(b"%PDF-1.4 dummy")
+            result = self.runner.invoke(
+                app,
+                [
+                    "--input", "input.pdf",
+                    "--output", "output.pdf",
+                    "--passwd", "secret",
+                    "--force",
+                ],
+            )
+        self.assertEqual(result.exit_code, 1)
+
+    # ------------------------------------------------------------------
+    # get_typer_app helper
+    # ------------------------------------------------------------------
+
+    def test_get_typer_app_returns_app(self) -> None:
+        """get_typer_app() should return the configured Typer instance."""
+        from passifypdf.cli import get_typer_app
+        result = get_typer_app()
+        self.assertIs(result, app)
diff --git a/uv.lock b/uv.lock
new file mode 100644
index 0000000..bda0207
--- /dev/null
+++ b/uv.lock
@@ -0,0 +1,3 @@
+version = 1
+revision = 3
+requires-python = ">=3.13"