GZip Compression

[cs_jono]

Hey,

Was just going through the admin section of ZC and came upon a section called GZip Compression. Can someone please tell me what exactly this setting controls within ZC?

[Qdixon]

gzip is how content is transported to the browser, generally it is more efficient to have it on...but on some servers it may be a bit slower in response time. It is default off and is a server specific optimization function.

[cs_jono]

What do you mean by it is how content is transported to the browser? Is it something that tells commands the browser what to read? Why is it more efficient to have it turned on instead of off? How do you know for your specific server if it's better or not?

Thanks so much in advance!

[Qdixon]

gzip is a compression algorithm...what it does it makes the server with the website compress the information being passed to your computer browser where it already knows how to decompress it and view it.

Without gzip enabled you are viewing a webpage load before your eyes, some parts loading at their own pace. With gzip enabled it generally gives a slight stall and appears instantly all at the same time.

The server really depends on what is running on it and how you website is setup. Best thing is to look at the difference by switching it on and off.

Gzip is good for quick loading or optimized sites and bad for sites that have a lot of big pictures or slow server connections.

For the most part you want it enabled, but it really depends on your server and the needs of your site.

[Website Rob]

Actually, I would disagree with having gzip ON. It is OFF by default and there is a good reason for that.


Basically, it's the same as sending a Letter. Puts everything into an evelope or container and when received, it must be opened. Each OS has it's own method of sending / opening these containers.

gzip came first and it worked so well it was ported to Windows and called Zip. Forget what Mac calls it.

Works great for sending large eMails, with lots of photos or attachments, but for Web sites and pages it can cause problems.

[cs_jono]

Website Rob, I am a little confused now, how does it cause problems?

Thanks in advance for your reply!

[Website Rob]

Using 'gzip' for Web related files means:
A) using another process and thus, potentially slowing things down
B) needing to store the gzip file somewhere

The 'tmp' directory for the Server is the usual place to store certain files like this but nowadays, security is tighter than what it used to be. Thus, using gzip for a Web site can problems from: blank web pages to things just not working properly at all.

It was handy to use 'gzip' for Web related files when Server hardware did not have the speed it does today and tight security was not a necessity. Those days are long gone.

'gzip' still has it uses but not the best method for trying to obtain faster load times. For that, best to be on a well maintained Server that is not overloaded.

[cochlear]

I talked to my host today about GZip, and got some interesting info on the performance side of things.

I was told that GZip has its use for very large sites like Yahoo (I guess that's why Yahoo includes gzip as a performance tip), but for my site the benefit is minimal. For this reason my host doesn't even do it.

So what does this mean for my Zen Cart store, which has GZip turned on? Well, apparently GZip is still performed by Zen Cart's PHP code, just not by my host (just paraphrasing, I know little about these things interact with each other). However, CSS and HTML do not go through PHP, so they are not zipped. If I want to I can always upload compressed versions of these files (anyone tried this?).

Anyway I think I'll follow the experts advice and forget GZip.