The issue explained more thoroughly

Let's reiterate: When a customer completes an order in Magento, he is redirected to the succes page (with the URL checkout/success). This page shows a bit of information like which order was completed, and that the customer receives some mail. But there are various opportunities to pick up on this page:

• Thank the customer for the purchase
• Add product-specific details that the customer might need
• Invite the customer to share product information through social media (Facebook, twitter)

There might be many more tricks that can be applied to this page, but you'll get the picture: If you are sales minded, you will want to modify this page. So you modify the underlying PHTML-template templates/checkout/success.phtml and refresh the page. Damn, instead of viewing the modified contents, you are redirected back to the empty cart page and your order information is gone.

Making an extension to improve testing things like this

The normal solution would be to repeat the entire procedure. So, add products to the cart, go to the checkout, complete all steps in the checkout and end up on the success page again. If you are making tiny modifications, this process is time consuming and quite annoying. We at Yireo hate that. So we created a simple but effective extension to solve this issue once and for all: Yireo CheckoutTester.

The free CheckoutTester extension allows you to preview the success page under a specific URL. Even better, you can take any order already placed in your shop and use that as preview data of the success page. Now, every time when you modify the success page, you can simply navigate to the CheckoutTester URL and refresh the page as many times as you like. Testing made smarter. If you are customizing Magento to increase conversion, this is a must have. And it is free.