Why does running `flask run` on Windows result in “flask is not recognized as an internal or external command, operable program or batch file”? – Flask

The Problem:

When running the command flask run on Windows, some users encounter the error message "flask is not recognized as an internal or external command, operable program or batch file". This error prevents the Flask application from running properly.

Solutions:

Solution 1: Use python -m flask run

Instead of using flask run, try running the command python -m flask run. This command ensures that the Flask module is executed correctly and avoids the "flask is not recognized" error. Make sure you are in the same directory as the application.py file.

Solution 2: Install Flask in the Current Directory

If you are working in a different directory where Flask is not installed, you can install Flask in the current directory using the following command:

pip install flask

This will install Flask and make it available for use in the current directory. After installation, try running flask run again.

Solution 3: Reinstall Flask

In some cases, the issue may be caused by a corrupted or incomplete installation of Flask. To fix this, you can uninstall Flask using the following command:

pip uninstall flask

Once the uninstallation is complete, close the command prompt and reopen it as an administrator. Then, reinstall Flask by running:

pip install flask

After the reinstallation, verify the Flask version using the command flask --version.

Conclusion:

The error "flask is not recognized as an internal or external command, operable program or batch file" can occur when running flask run on Windows. This issue can be resolved by using python -m flask run, installing Flask in the current directory, or reinstalling Flask. By following these solutions, you can successfully run Flask applications on Windows without encountering this error.

Sources:

• Flask Documentation{target="_blank"}