Is it easy to upgrade from symfony2 to symfony 3 ?

Symfony2.7 beta1 is going to be released later today and it is going to be the next LTS (Long-Term-Support release). People still on Symfony2.3 have a year (until May) to upgrade to Symfony2.7.

Symfony2.7 is a special release. Even if it comes with more than new features (big and small), a lot of work was done on the deprecation notices framework. These notices help you easily upgrade to Symfony3.0 starting today, and they also ensure that everything works as expected in the core framework: compatibility between Symfony2.7 and3.0 where applicable, no usage of deprecated features in the core framework, ...

As I already explained a few months ago, the3.0 version is a semantic version bump.3.0 is allowed to break backward compatibility; but not by adding new features or by breaking compatibility; Symfony3.0 breaks backward compatibility because the compatibility layer introduced in all2.x versions will be removed. So, all new features from3.0 were introduced in2.x versions already. And because2.7 is feature-freezed now, it means that all features for3.0 are already known and we cannot deprecate anything anymore... and that's a problem. Because all the work done in3.0 won't have an easy upgrade path anymore starting from today. Of course there is a solution.

I've talked with a lot of people about the best solution to address this problem and I came up with a simple and efficient solution: the need for a Symfony2.8 version. This version will work as any other2.x versions, we will be able to add new features, deprecated other ones, and provide a good upgrade path to Symfony3.0.

Symfony2.8 will be released in November at the same time as Symfony3.0. Symfony2.8 is going to be a LTS release as well to allow people to still have a year to upgrade from2.8 to3.2 when it comes out (3.2 being the next LTS release and the first one of the3.x branch).

Let me recap:

• Symfony2.7 is going to be released as planned in May and will be a LTS release;
• Symfony2.8 will be released as planned in November and will be a LTS release as well;
• Symfony3.0 will be released as planned in November at the same time as Symfony2.8.

That depends. If you are looking for easy upgrade I'd recommend using a platform for hosting Symfony application. Here is a tutorial on how you can upgrade Symfony version if you are using such a platform: https://www.cloudways.com/blog/upgrade-symfony-2-to-3/