What is the difference between the classic WooCommerce checkout and Cart and Checkout Blocks?

The classic WooCommerce checkout runs on the [woocommerce_checkout] shortcode, rendered through your theme’s PHP templates and customized with PHP hooks and filters. Cart and Checkout Blocks are a full rebuild using React, customized visually in the block editor and extended through a JavaScript Store API instead of PHP hooks. Blocks have been the default for new WooCommerce stores on block themes since version 8.3, released in November 2023. The difference isn’t cosmetic, it’s a different technology underneath, which is why plugin compatibility is the main thing that decides which one you should actually be running.

Classic checkout vs Checkout Blocks

Are all payment gateways compatible with Checkout Blocks?

No. Gateway and plugin support for Checkout Blocks varies, and older or less-maintained ones are the most likely to lack it. If your only active payment gateway is block-incompatible, WooCommerce shows a visible warning on the checkout page instead of failing silently. You can revert to classic checkout with one click, from inside the Payment Options block’s settings sidebar, no developer needed.

This isn’t hypothetical. On WooCommerce’s own support forums, a store owner was told the Eway Payment Gateway by WebAware was installed, active, and confirmed incompatible with their store’s block-based checkout, with support pointing them to WooCommerce’s own Eway gateway plugin as the compatible replacement.

Which one should you use

Best if launching a new store: use Checkout Blocks. Launch on a block theme, confirm your payment gateway and any checkout-modifying plugins explicitly support blocks. Most major gateways support blocks at this point.

Best if you can’t confirm block support: stay on Classic checkout. If your store depends on a payment gateway or checkout extension that hasn’t published block compatibility, or you’re running custom checkout logic that would need rebuilding against the Store API, Classic is still fully supported. WooCommerce keeps shipping bug fixes for it even though new feature work goes to Blocks.

If you’re not sure which category your store falls into, check each active payment and checkout plugin’s changelog or product page for explicit block support before switching anything on a live site.

Can you switch back if it doesn’t work out

Yes. Both the Cart and Checkout blocks can be transformed back to their classic shortcode equivalents using the “Transform” option in the block toolbar. Since the two blocks work together, revert both at once rather than switching only one, otherwise you’ll end up with a mismatched cart and checkout experience.

For most new builds, Checkout Blocks are the right default, the conversion data and WooCommerce’s own development direction both point that way. For an established store, the honest first step is a plugin compatibility audit before touching anything, not a blanket switch. If you’d rather have someone check compatibility and handle the migration safely, Stagebit’s WooCommerce development team does exactly this kind of checkout migration work.