I'm getting mixed results when I search for this topic.
I need to upgrade my PHP-Version to 5.6.
I have an existing T3-Installation with Version 6.1.8 and am planning to upgrade another Version from 4.7 to 6.2 (can't go to 7 because of Templavoila [sic]).
So the question is: are T3 V 6.1.8 and 6.2.x compatible with PHP 5.6?
(I'm aware that I need to update the currently installed extensions that are running under 4.7 now).
I ran some tests on my localhost with PHP 5.6 and they went fine - just not sure if this will work «in the wild» as well...
Any clarification would be awesome ;)
Typo3's source code is stored on Github, so you can explore the version history very easily
Each version includes an INSTALL.md file, which details the requirements and compatibility.
The one for v6.2 is here: https://github.com/TYPO3/TYPO3.CMS/blob/TYPO3_6-2/INSTALL.md
Reading this file, it says:
Server system requirements
PHP >5.3.7 up to 5.5 (PHP 5.4 or later recommended)
This implies that it is not compatible with PHP 5.6.
However, I suspect a more likely scenario is that it was simply released before PHP 5.6 was available, so they are just quoting "up to 5.5" because it was the highest version available at the time. There is very little in the way of breaking changes between PHP 5.5 and 5.6, so it is unusual for a package to work with 5.5 and not 5.6, particularly if it is a well-written and maintained package like Typo3.
I will note that Typo 6.2 is still being maintained (the last update in Github shows as just a few days ago), so given that PHP 5.6 is the most widely used PHP version as of right now, the chances are very high that it will have been updated to PHP 5.6 compatibility at some point, even if it it wasn't compatible when intially released.
So my gut instinct tells me that you should be okay with 5.6 if you want to risk it. However if you want certainty you will probably be better to follow their recommendation and stick with 5.5.