WooCommerce classic vs block checkout for peptide stores
We see this one constantly: a founder installs a payment plugin their processor recommended, everything looks configured, and the card option is nowhere on the checkout page. The plugin isn't broken. The store is using a checkout the plugin doesn't support.
The two checkouts
| Classic checkout | Block checkout | |
|---|---|---|
| How it's built | A page with the [woocommerce_checkout] shortcode | A Checkout block in the WordPress editor |
| Default for | Stores created before WooCommerce 8.3 | New stores since WooCommerce 8.3 (Nov 2023) |
| Payment plugin support | Almost every gateway, including older and custom ones | Only gateways that added block support |
| Custom code and fields | Years of snippets and plugins work with it | Needs block-aware extensions |
| When it fits | High-risk gateways and custom payment plugins | Gateways that clearly list block support |
How to check which one you have (2 minutes)
- In WordPress, go to Pages and open your Checkout page.
- If you see
[woocommerce_checkout], you're on classic. - If you see a Checkout block with sections like Contact information and Payment options, you're on block.
Symptoms of a mismatch
- The card payment option doesn't appear at all
- Customers see “There are no payment methods available”
- The card fields appear but Place order does nothing, or the token never gets created
- Everything works in the admin preview but not for real customers
Fixing it
Option 1: switch to classic. WooCommerce has a one-click switch in the Checkout block's settings. It's the fastest fix when your gateway only supports classic. Test on a staging copy first if you have custom fields or styling.
Option 2: use a gateway with block support. If you're choosing a processor now, ask the gateway provider directly whether their WooCommerce plugin supports the Checkout block.
Option 3: add block support to a custom plugin. It's real development work, not a setting. Worth it only if you need block-only features.
Before you launch, ask these three questions
- Does our payment plugin support the checkout type we're using?
- Has someone placed a real order on the live checkout, not just the preview?
- If we change processors later, does the new plugin support the same checkout?
If you're stuck on this, message us. It's usually a quick fix. And if WooCommerce keeps fighting you, our Genesis Biomapping case study shows what moving to a custom store looks like.
Frequently asked questions
What's the difference between WooCommerce classic and block checkout?
Classic checkout is the older shortcode-based checkout page. Block checkout is the newer version built with the WordPress block editor. Since WooCommerce 8.3 in November 2023, new stores get block checkout by default.
Why doesn't my payment method show up at checkout?
Many payment plugins, especially custom or high-risk ones, were built for classic checkout only. If a gateway doesn't support the Checkout block, it may not appear, and customers can see 'There are no payment methods available.'
How do I tell which checkout my store uses?
Edit your Checkout page in WordPress. If you see a [woocommerce_checkout] shortcode, it's classic. If you see a Checkout block with inner blocks like Contact information and Payment options, it's block checkout.
Is it safe to switch back to classic checkout?
Generally yes, and WooCommerce offers a one-click switch in the Checkout block settings. Test on a staging copy first, especially if you have custom checkout fields or styling.
Which checkout should a new peptide store use?
Use whichever your payment gateway fully supports. For many high-risk gateways today that's classic. Ask your developer or gateway provider before you launch, not after.
Sources and further reading
Where we can help
We build the whole business: store, payments, email and SMS, SEO, AEO + GEO, and supplier introductions.
See the done-for-you launch →More guides
- Approved, but every card still declines?: Tell an account problem from a code problem in 10 minutes.
- How a peptide checkout should work: Tokens, secret keys, refunds and double-charge protection, in plain English.
- The peptide payment backup plan: What to set up before a processor drops you, and what to do if it does.
- How to start a peptide business: The steps, in order, from business setup to first order.
- Peptide business startup costs: Every cost category, with a calculator that shows its math.
- Peptide supplier due-diligence scorecard: How to vet a wholesaler before you buy inventory.
- SEO vs AEO vs GEO for peptide sites: What each one is, and why peptide brands need all three.
- Peptide business launch checklist: Ten sections to finish before you open.
Written by the PepFounders team. This is general business information, not legal, tax or regulatory advice. Product classification and what you can sell depend on your products and markets, so talk to a licensed attorney.