What is the maximum number of products per order that Commerce supports?

Due to the way Commerce calculates items and products the performance starts to deteriorate noticeably at around 15-25 different products in the cart.

At around 50 different products, the cart definitely struggles and is likely to either timeout, or timeout the customers' patience.

The precise number of different products where Commerce no longer performs to your requirements will depend on your exact requirements, your server, and how you're using Commerce.

For the server, there are a few considerations that can either boost or hurt performance:

• PHP 8 is much faster than PHP 7. Make sure you're on PHP 8.1 or higher.
• The process is fairly database intensive. If your database is networked rather than local, that can significantly adversely impact the performance at larger quantities.
• The process is also fairly CPU heavy. Faster modern CPUs may be able to shave off some time.

Other factors in Commerce that can harm performance:

• Product price types and shipping methods are checked with almost every change to the order. Make sure those are not repeatedly hitting up APIs or doing complex math.
• Same with modules that hook into the cart or checkout process.

We try to improve the checkout performance a little in every release. However, if your customers routinely order 25-50 (or more) different products per order, we don't consider Commerce the right platform for your store.