If your Zen Cart Website is slow, there are a lot of things you can do to improve its speed. It's unlikely any one of them will provide drastic results, but the cumulative gains might fix slowing you're experiencing.
To get to perform most of these fixes, you'll need to log in to your Zen Cart admin.
One of the easiest ways to improve slowness on your Zen Cart Website is disabling options you don't use. There are a number of them scattered throughout Zen Cart's menus — we've compiled a list of them here:
|Location||Rows (options) to turn off [false/OFF]|
|Configuration > My Store||Show Category Counts
Show Category Counts - Admin
|Tools > Layout Boxes Controller||sideboxes/manufacturers.php
|Configuration > Attribute Settings||Enable Downloads
Enable Price Factor
Enable Qty Price Discount
Enable Attribute Images
Enable Text Pricing by word or letter
|Configuration > Index Listing||Show New Products on Main Page
Show Featured Products on Main Page
Show Special Products on Main Page
Show Upcoming Products on Main Page
Show New Products on Main Page - Category with SubCategories
Show Featured Products on Main Page - Category with SubCategories
Show Special Products on Main Page - Category with SubCategories
Show Upcoming Products on Main Page - Category with SubCategories
You can reduce the speed of your Website by using images that are only as large as you need (for example: small images for thumbnails).
Zen Cart has documents that can help you with this, as well:
If your store contains a lot of products, dividing them into subcategories can help improve your load time. Zen Cart has those instructions in How do I add a category, subcategory or product?.
By default, Zen Cart treats all products as "new products." Reducing the timeframe this window uses can reduce your load time.
GZip compression will reduce the amount of data you send to visitors, which can help over slow internet connections.
Your stylesheet affects how your website looks; depending on how it was created, it can contain links to images hosted on other websites, which can cause slowing.
For help determining where these files might be, you can search your website using WebSiteOptimization.com.