Bootstrap 4 Uncaught Referenceerror Popper Is Not Defined

Have you ever encountered the frustrating "Uncaught ReferenceError: Popper is not defined" error while working on a Bootstrap 4 project? You're not alone! This common issue can be easily resolved with a few simple steps. Let's dive in and troubleshoot this error together.

When you see the "Uncaught ReferenceError: Popper is not defined" error in your browser's console, it typically means that the Popper.js library is not properly included in your project. Popper.js is a library used by Bootstrap for advanced tooltips and popovers.

To fix this error, the first thing you should check is whether you have included the required Popper.js library in your project. In Bootstrap 4, Popper.js is a mandatory dependency for certain components to work correctly. So, make sure you have added the Popper.js script to your HTML file before the Bootstrap.js script.

Here is an example of how you can include Popper.js and Bootstrap.js in your HTML file:

<!-- Include Popper.js -->


<!-- Include Bootstrap.js -->

By adding these script tags in the correct order, you ensure that the Popper.js library is loaded before Bootstrap.js, resolving the "Popper is not defined" error.

In case you are using a package manager like npm or Yarn to manage your project dependencies, you can install Popper.js along with Bootstrap by running the following commands in your terminal:

npm install @popperjs/core bootstrap

Once you have added Popper.js to your project and included it before Bootstrap.js, refresh your browser and see if the error persists. If you have followed these steps correctly, the "Uncaught ReferenceError: Popper is not defined" error should no longer show up, and your Bootstrap 4 components should work as expected.

It's worth noting that keeping your libraries and dependencies up to date is essential to prevent compatibility issues and errors like the one we discussed. Make sure to check for updates regularly and follow best practices for managing dependencies in your projects.

In conclusion, the "Uncaught ReferenceError: Popper is not defined" error in Bootstrap 4 is a common issue caused by the missing Popper.js library. By including Popper.js before Bootstrap.js in your project and ensuring both are up to date, you can easily fix this error and continue building awesome web applications with Bootstrap. Happy coding!