What causes "TypeError: myFunction is not a function"?

A variable was overwritten with a non-function value Calling a method that doesn't exist on an object Importing a named export as a default export (or vice versa) Calling an async function without await and then calling .then() on the result incorrectly A typo in the function name

JavaScript Error2 Fixes Available

TypeError: X is not a function

TypeError: myFunction is not a function

What does this error mean?

This error means you tried to call something as a function, but it isn't one. The variable holds a different type (string, number, object, undefined) instead of a function.

Common Causes

A variable was overwritten with a non-function value
Calling a method that doesn't exist on an object
Importing a named export as a default export (or vice versa)
Calling an async function without await and then calling .then() on the result incorrectly
A typo in the function name

How to Fix It (2 Solutions)

Check what the variable actually contains

Log the variable before calling it to see its actual type.

Code

console.log(typeof myFunction); // Should be 'function'
console.log(myFunction);        // Inspect the actual value

Verify your import statement

Ensure you are using the correct import syntax for the module.

Code

// Named export
import { myFunction } from './module';

// Default export
import myFunction from './module';

Related Errors

JavaScript

TypeError: Cannot read properties of undefined (reading 'bgColor')

View fix

JavaScript

TypeError: Cannot read properties of undefined (reading 'toLowerCase')

View fix

JavaScript

TypeError: Cannot read properties of undefined (reading 'indexOf')

View fix

Browse all error fixes