Your WooCommerce checkout is broken. Customers are hitting a spinner, a blank page, or a payment error — and every minute it stays down costs real sales.
After fixing dozens of WooCommerce stores, the cause almost always falls into one of 10 categories. Here's how to diagnose and fix each one.
1. Caching Plugin Blocking Checkout
Symptom: Infinite spinner, cart totals wrong, nonce errors.
Checkout must never be cached. Exclude these from cache AND your CDN:
/cart//checkout//my-account/- Any URL with
wc-ajax=
Don't forget server-level caching — nginx FastCGI cache or Varnish won't be cleared by your WordPress cache plugin.
2. Plugin Conflict
Symptom: Checkout works in safe mode but not normally.
Use the Health Check & Troubleshooting plugin to enable safe mode (disables plugins for admin only). If checkout works, re-enable plugins one by one until it breaks.
Most common offenders: JS minifiers, CAPTCHA plugins, checkout field editors.
3. Theme Incompatibility
Symptom: Layout broken, checkout form doesn't submit.
Switch to Storefront theme temporarily. If checkout works, your active theme is the problem.
4. JavaScript / AJAX Errors
Symptom: Place Order button does nothing.
Open Chrome DevTools → Console. Look for red errors. Disable JS combining/deferring options in your speed plugin specifically for checkout pages.
5. SSL / Mixed Content
Symptom: Payment fields missing, browser shows broken padlock.
Payment gateways require HTTPS. Force HTTPS site-wide and run a search-replace to update any http:// database URLs.
6. Payment Gateway Misconfiguration
Symptom: Silent payment failure or "Unable to process payment."
Check: API keys (live vs test mode), webhook URLs, currency settings. For Stripe, check Developers → Webhooks for delivery failures.
Stripe plugin versions 9.4.0 and 9.5.0 (April–May 2025) had a checkout-breaking bug. Update immediately if you're on either.
Symptom: "No shipping methods available" blocking checkout.
WooCommerce → Settings → Shipping — confirm at least one zone covers your customers' countries with an active method.
8. Outdated WooCommerce or PHP Version
Symptom: Works for some users, broken for others.
Update WooCommerce core and all gateway plugins. Confirm PHP 8.1 or 8.2 — PHP 7.x causes major compatibility issues.
9. PHP Memory Limit Too Low
Symptom: 500/502/504 errors during checkout.
Add to wp-config.php:
define( 'WP_MEMORY_LIMIT', '256M' );
define( 'WP_MAX_MEMORY_LIMIT', '512M' );
10. Outdated Template Overrides
Symptom: Layout oddities after WooCommerce update.
WooCommerce → Status → System Status → scroll to Template Overrides. Any flagged in red need updating to match the current WooCommerce version.
Full guide with diagnostic checklist: amanurrahman.com/blog-post/woocommerce-checkout-not-working