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Upgrading Magento 2.2 to 2.3 – Easy step by step instructions

Step one: 

Before we do anything – go ahead and backup your store, we’ll need to backup the codebase and the database, this should be a smooth upgrade but you never know (it is Magento afterall…) You’ll be thankful that you can revert back to a working version of your magento store easily if something goes wrong during the upgrade process. Backing up your store for things like this is important, don’t underestimate this step!

You can do this via the Magento CLI, or for peace of mind you may prefer exporting the database manually.

We’ll assume you’re using a sane way of versioning and maintaining your magento stores codebase, like GIT or SVN. We’ll be using GIT so we can create a new branch and use this branch to perform the upgrade from Magento 2.2 to Magento 2.3 and test it before merging it back in to your master branch. Ensure your composer.json  is backed up too in your repository.

Step two:

With our magento store safely backed up, we can go ahead and begin the upgrade process. It’s relatively easy in Magento 2 as majority of it is handled by updating your composer file. This is done usually via the command line. Run the following commands to kickstart the upgrade process.

This will add the new Magento 2.3 dependencies to your composer file:

composer require magento/product-community-edition=2.3.0 --no-update

This will add third party dependencies that the new 2.3 system uses:

composer require --dev phpunit/phpunit:~6.2.0 friendsofphp/php-cs-fixer:~2.10.1 lusitanian/oauth:~0.8.10 pdepend/pdepend:2.5.2 sebastian/phpcpd:~3.0.0 squizlabs/php_codesniffer:3.2.2 --no-update

This will remove some third party dependencies that are no longer used:

composer remove --dev sjparkinson/static-review fabpot/php-cs-fixer --no-update

Now open the  composer.json  file and add  Zend\\Mvc\\Controller\\": "setup/src/Zend/Mvc/Controller/  into the “psr-4” section.

The psr-4 section in your composer file should now look like the following:

"autoload": {
    "psr-4": {
        "Magento\\Framework\\": "lib/internal/Magento/Framework/",
        "Magento\\Setup\\": "setup/src/Magento/Setup/",
        "Magento\\": "app/code/Magento/",
        "Zend\\Mvc\\Controller\\": "setup/src/Zend/Mvc/Controller/"

And finally, you’ll want to change the “version” attribute in your composer.json  file to  2.3.0, this step is more for you and your developer friends sanity the next time you open this composer file, they wont be confused by wrong version numbers.

… Now for the moment of truth, to tell composer to install and update the new dependencies, we run on the command line:

composer update

Once that’s complete, you’ll want to remove the var caches and generated directories. If you use Redis or Memcached, you’ll want to flush the cache for these.

rm -rf var/cache/*

rm -rf var/page_cache/*

rm -rf generated/code/*

Finally, kickoff the install and upgrade scripts using:

php bin/magento setup:upgrade

Step three:

Congratulations! Your store should be now updated to Magento 2.3.

If you visit your website and you get a PHP syntax error that looks like “syntax error, unexpected ‘?’, expecting variable (T_VARIABLE) ” or  a 500 error, try checking/switching your PHP version to 7.1.3+, this is a new requirement for Magento 2.3. If you was running Magento 2.2 on PHP 7.0.13 this might be a common issue with the upgrade.

However an often overlooked step is to check any third party or custom extensions that you’ve installed don’t have any deprecated/breaking code changes in them. This upgrade is quite tame and doesn’t seam to have many breaking changes, but be sure to check out the official Magento 2.3 breaking changes list here.

If you get an issue with composer and an error that includes  requires composer-plugin-api ^1.1 – try updating your composer using  composer self-update as it may just be a little out of date.

Need help or just want to consult with us on your latest Magento or eCommerce project?


Mike Sheward

Technical Director

Mike is our Technical Director who has worked on eCommerce projects since 2014 and has been with Develo since 2015. He became certified in Adobe Commerce in 2023. Mike’s favourite aspect of web development is tackling intricate eCommerce challenges with the bespoke platform Magneto/Hyvä, and he tells us his best achievement from working at Develo is fostering a culture of growth and innovation within our team. Outside of work, he can be found spending time with his family, baking and walking his dogs.

Develo is a leading Magento agency and eCommerce web development company based in Birmingham, in the UK, serving clients globally since 2010. We provide our Learn articles to share knowledge of magento web development, web app development and more to the wider web developer community. To extend your team with our white label web developers, collaborate or consult with us on your project contact us here.



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