Oftentimes, you might come across the error "bad auth: authentication failed." What does this error mean?
"Bad auth" means the authentication method is not proper due to providing wrong username or password; hence, it failed.
This blog will discuss the possible mistakes we make for which this error appears and the solutions we can try to fix the error.
1) using whitespaces
When you put your username and password, do not add any whitespace (extra space) before and after your username and password in the MongoDB string connection.
const uri =
const uri =
2) username and password did not match
Check if the username and password in your MongoDB connection string matches with the username and password in your mongodb database access
Correct: Username and password matches
3) Forgot to save username and password
Make sure you have clicked the 'Add User' button after creating the username and password in your database access.
4) Using angle brackets
Do not put your username and password inside the angle brackets like the picture below:
5) Environment variables did not match
If you are using environment variables, make sure you have written them correctly in your MongoDB connection string
Did not match
6) Do not add any space when assigning your secret information to the environment variables
7) Don't forget to do the following before using the environment variables
Always check if you have installed dotenv in your package.json. If you haven't, then run this command to install dotenv
npm i dotenv
After installation, make sure you have imported dotenv
Take time and go through your code to see if you have made the mistakes discussed above when your authentication fails. I am sure one of these solutions will help you connect your MongoDB successfully. Happy coding!!!