Yes it's safe.  How easy it is depends on your hosting provider.

You may experience some bugs with certain plugins on 7.4
7.3 should work perfectly.

7.1 might sound old, but PHP versions stick around for a long time. 45% of the world still uses version 5.

Which PHP version did you upgrade to?  (and which version of Piwigo are you running on it?)
I'm also on Dreamhost and got an email saying they would be shifting to 7.3 next week some time.
When I originally set up Piwigo it wouldn't work right in anything higher than php 7.1, so that's what I've been using.  (I'm also due for a Piwigo update.)
Before I dive in and do all this long-delayed maintenance I want to be sure things will still work afterwards.
Thanks!

Thanks! 
I just:
(1) backed up my files and database
(2) updated Piwigo to 2.10.2
(3) updated php to 7.3 FastCGI at Dreamhost

All seemed to go "easy-peasy".

At first I didn't see any difference at all, but then I logged out and logged back in and saw the "new" Modus theme (I was using Bootstrap Default) . . . will need to figure out my new options there . . . but so far everything seems to be working fine.  Many of my plugins got disabled, so I'll need to sort out which, if any are important anymore.

All in all things went smoothly. 

It really helped to know someone else on Dreamhost had done this with no problems before I tried it.

Thanks so much!!

I advise you the opposite @Zentalquabula said, never update to the last version. Some CMS software may be unprepared for this and generate errors or don't work. Use an older PHP version but preferably to have the latest update of the version, for example if you use 7.2 branch make sure you use latest version of 7.2 to have the latest security updates.

there haven't been significant gain in speeds from 7.0 to latest 7.4 . the true speed gain is when switching from 5.6 to 7.0 , the latest is almost twice as fast https://kinsta.com/blog/php-benchmarks/

Last edited by eliz82 (2020-08-29 19:40:05)