Let’s get straight to the point. The answer will be NO in majority of cases.
Joomla, as any other kind of software (like Windows, Mac OS or Linux) evolves through time and new versions are released on a regular basis by the community. Question is: do you really need to upgrade to a newer version? Basically, if you’re happy with your site and you don’t plan any upgrade and especially if you don’t have a big budget then the new version isn’t probably for you.
Yes the official support stopped on December 31 2014 for Joomla 2.5. What does that mean? It just means that there won’t be any other security or stability fix and that third-party developers will be no longer delivering components for this version of Joomla in the future. The latest 2.5 version at the time of writing is the version 2.5.28 and numerous security fix has been released already. If you’re running this version, you can then be confident that your website is unlikely to get hacked even if the zero risk situation doesn’t exist. If you’re not running the 2.5.28 version, please upgrade!
We have numerous clients currently running the even older version of Joomla, the version 1.5 for years without any issues.
Migrating to a newer Joomla version (3.3 at the time of writing) is a complex and expensive process in most cases as some of the core engine functions are not compatible with both versions. You should upgrade your site to a newer Joomla version only:
- if you have a very specific upgrade/plan to execute on your site like using a component which is only Joomla 3.3 compatible
- if you have enough budget/time for the migration
Never try to upgrade your Joomla site from 2.5.x to 3.x if you’re not a Joomla expert. Chances is that you will only be able to break your website.
In any case, running a regular backup of your site should always be the top priority in your maintenance schedule.