Error Merge JavaScript Files/CSS File

[filippo_scifo1]

Hi All,

I've very big performance issue with my magento installation, I'm trying to optimize the site, but when I try to merge JS and CSS the website is not showing right.

Any suggestion?

I've read that marging JS an CSS can be very good for performance, but in this way I'm not able to try this solution due the error.

Can anyone help me?

Thanks

[JLHC]

Merging CSS and JS may not work properly with all configurations and themes so if it doesn't work, you should keep it disabled. 

Besides that, this wouldn't give you too much performance increase and may even slow things down if your server supports HTTP/2 . 

[filippo_scifo1]

Thank you for the response.

I supposed merging is not always compatible...

I don't know how to proceed with optimization:

https://developers.google.com/speed/pagespeed/insights/?url=shop.matranga.it&tab=desktop

the performace are very slow and the biggest issue seems linked to 

Defer parsing of JavaScript

Minify JavaScript

Can you help me how to address this with magento?

Thank you

[JLHC]

Taking a look at the report, the biggest issue is definitely not JavaScript related. 

Under "Reduce server response time", it states that your server responded in 7.5 seconds which is taking too long. 

This can be due to multiple reasons from third-party extensions, themes, slow server or all of them. 

You may want to try enabling Magento Profiler to see if it identifies any possible cause of slowdown. 

If extensions and themes are not causing the slowness, the problem may be server related in which case you may want to try running your website from another server to see if that speed things up. 

[filippo_scifo1]

Hi James,

thanks a lot for your support, I've already activated profiler, this is the result (first part) but not clear how to proceed now, consider I've also created a dev environment and the response time is always very slow: