What to do when customers cannot add items to the cart

Why does this happen?

Online shops run on software such as PrestaShop, OpenCart, Magento or VirtueMart. When the cart button does nothing, one of a few common things is wrong. Work through the checks below in order. Take a backup before you change settings or files.

Checks for shop owners

1. Clear the shop cache. A cache is a saved copy of pages. An old copy can hide changes. Find the cache option in your shop admin panel and clear it.
2. Check the stock. If a product has zero stock, many shops block the cart button. Open the product and raise the quantity.
3. Check the product is active. Make sure it is enabled, has a price, and is in a category.
4. Check required options. Some products need a size or colour first. Make sure all options are valid.
5. Turn off new add-ons. If the problem began after you installed an extension or theme, switch it off and test again. Extensions often clash.
6. Switch to a default theme. If the cart works with the default theme, your custom theme has a fault.
7. Look for browser errors. Open the shop, press F12, and click the Console tab. Click the cart button. Red messages point to broken JavaScript, the code that makes buttons work. Share them with your developer or support.
8. Check the cookie and session settings. The shop stores your cart using a session, a short-term memory for each visitor. If the shop address changes between http and https, or between www and non-www, the cart can empty. Pick one address style and use it everywhere.
9. Check the SSL settings. If your site has an SSL certificate, make sure the shop is set to use HTTPS. An SSL certificate encrypts data between the visitor and your site.
10. Check disk space and folder permissions. If the session folder is full or not writable, carts fail. Ask Hostvento support to check this.
11. Check PHP version. PHP is the language your shop runs on. If you updated PHP recently, the shop software may not support it. Switch to a version your shop supports.
12. Check the error log. Your control panel or File Manager may have a log file named error_log. Read the last lines for clues.

Checks for customers

• Refresh the page.
• Try another browser.
• Clear cookies for the shop.
• Turn off ad blockers for the shop.

If nothing works, open a support ticket with the shop address and the steps you already tried.

Quick recap

• Clear the cache and check stock and product status.
• Turn off new extensions and test with a default theme.
• Look at browser console errors and the server error log.
• Keep one consistent address and use HTTPS.
• Ask support if the problem remains.