E-Commerce conversion rate reduced dramatically after adding a new payment processor

Hello. We've been using Stripe, and we had a really good conversion rate. However, Stripe decided to stop working with us, and we had to switch to another payment processor - Cardinity.

After switching to it, our conversion rate dropped a lot.

Trying to figure it out why:

When we used stripe, we had:

1. Internal payment page
2. No 3D secure checkout.

Once we started to use Cardinity, we got:

1. External payment page (people are being redirected to another page (official Cardinity page) to make the payment)
2. 3D secure checkout

Which one causes the biggest drop in conversions?

3D secure checkout or external payment page?

Or both? What are your opinions?

External payment page may lead to security concern and also does not look so professional in the mind of buyers while 3D checkout is inconvenience. Both could be contributing for the reason but I personally feel, external payment page is bigger factor. People won't mind to take little inconvenience for safety which 3D provides

Buyer behaviour definitely changes when being redirected. Less clicks, less pages = more sales.

Yes. Sometimes people dont have their 2FA device with them or something. They too lazy to complete 3d secure. Your product maybe is not so necessity that they really need to buy it.

So that why your conversion rate dropped. They too lazy to pick up and make 2FA for 3D for your product

As suggested by other members, the external checkout page will drop your conversion rate.

External Payment Page.
Too much steps for pay action.

By the way, you can set up an internal payment page using third-party software such as Payment Orchestration Platform and connect Cardinity to it as a payment gateway. This can potentially give you back your conversion rate.

From my experience external checkout doesn't matter much.

While forcing 3D payments completely kills conversions. It's definitely the culprit. 3D should always be optional, if possible.

Maybe Cardinity requires 3D as they deem your business as high-risk. Also they are a small payment provider, their international card acceptance rates will likely be lower than Stripe even without 3D. I recommend to look for other merchant providers.