JavaScript strict mode isn’t always the propounded choice, according to the German software engineer Arnold Abraham. He shares that he’s been wondering whether there is a reason not to use strict mode in JavaScript. Especially, when Google will tell you that this is definitely a good idea.

Arnold gave 21 reasons why we shouldn’t be obsessed with JavaScript strict mode in an article, published in Medium. Here they are:

1. The Suicidal Statement

2. Strict Mode → Runtime Errors → The Worst Ones!

3. Unnecessary Strict Mode Errors Flagged by ESLint Beforehand

4. Implied Globals

5. Non-writable Variables

6. Unique Object Literal Property Names

7. Unique Function Parameter Names

8. A Small Win of Strict Mode Turned Into a Loss

9. Octal Issues

10. Setting Properties on Primitive Values

11. Strict Mode Slows Down Your Code

12. Strict Does Not Simplify Variable Usage

13. Deleting Plain Names

14. arguments.callee

15. What Is Meant by “Securing”?

16. Referencing the Global Object in Functions

17. Walking the Stack

18. Strict Mode Could Impact the Future-Proofness of Your Work

19. There Can Be Issues Mixing Both Modes

20. Reserved Words

21. Function Statements

Then comes the question: Why do we have to use strict mode anyway, when we have tools like ESLint?

However, this is an individual decision to be made. So, if you prefer to work in strict mode, then do it. But if you and your project are better when not – here are 21 reasons why you are right to think so.