ExpressionEngine® User Guide

Legacy Documentation

You are using the documentation for version 4.3.8. Go here for the latest version.

Upgrading from ExpressionEngine 3

This guide will help you update your site from ExpressionEngine 3 to the latest version of ExpressionEngine 4.

See also

If you are upgrading from ExpressionEngine 2, you must first upgrade to ExpressionEngine 3 seperately. Use the version 3 files and see Upgrading from ExpressionEngine 2.

1. Backup and Prepare

  1. Back-up your ExpressionEngine database and files.
  2. Download the latest release of ExpressionEngine (either ExpressionEngine Core or the standard edition, whichever your site is currently running) and unzip the files to a folder on your computer.


Check your third-party add-ons to see if you need updated versions for v4. Most add-ons do not need updating from v3, or only need minor changes. Your add-on vendor(s) can let you know what, if anything, you need to do for your installed add-ons.

2. Copy Files

Working either locally with your backed up files, or on the server (not recommended), copy the following files from the newly downloaded release to your site:

  1. Copy admin.php to admin.php
  2. Copy index.php to index.php
  3. Copy system/ee/ to system/ee/
  4. Copy themes/ee/ to themes/ee/
  5. Copy system/user/config/license.key to system/user/config/license.key


If you’ve moved your system directory, make sure to change both index.php and admin.php to point to the correct directory. And don’t forget to update all admin.php files if you’re running your control panel from multiple Sites!

3. Run The Update Wizard

Go to your site’s control panel URL (typically found at or and follow the on-screen instructions to update ExpressionEngine.

4. Clean up

You’re Done! ExpressionEngine is now fully updated. But before you go…

  • If the updater could not automatically rename the installer, rename or remove system/ee/installer/ directory manually. The installer directory can be safely removed after installing ExpressionEngine.
  • To enable one-click updating, make sure your file permissions are all set.
  • Review the Version Notes since they outline any version-specific changes that you may need to make to your installation.
  • Review file permissions if something isn’t working quite right.