WooCommerce Checkout Freezes on Submit – JS, Cache & Hosting Issues

A WooCommerce checkout that freezes on submit is one of the most frustrating (and expensive) problems a store can have.

Customers click “Place order”, the spinner shows up… and then nothing happens:

• No error message
• No redirect
• No order created
• No payment triggered

When this happens, the issue is almost never “WooCommerce is broken.”
It’s usually a JavaScript failure, caching issue, blocked AJAX request, or hosting-level restriction.

This guide walks through the real causes, in the exact order you should debug them.

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What “Checkout Freezes on Submit” Actually Means

When a customer submits checkout, WooCommerce relies on:

• JavaScript validation
• AJAX (wc-ajax=checkout)
• Nonces
• Cookies / sessions
• Server-side processing

If any one of these fails, the checkout can appear frozen—even though something is breaking silently in the background.

Most of the time, the browser already tells you what’s wrong.

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Quick Symptoms Checklist (Before You Touch Anything)

Open DevTools → Console + Network, then click Place order.

Common things you’ll see:

• Console errors (red text)
• wc-ajax=checkout returning 400, 403, or 500
• Request stuck as “pending”
• Response body showing HTML instead of JSON
• No request at all (JS never fired)

If checkout works in admin previews but fails for real customers, this is often tied to the same root causes explained in
👉 Why WooCommerce AJAX Works in Admin but Not on Frontend

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Check 1: JavaScript Errors on the Checkout Page (Most Common)

One JavaScript error is enough to stop checkout entirely.

Common errors:

• Uncaught TypeError
• jQuery is not defined
• wc_checkout_params is undefined
• Payment gateway script errors

If the JS responsible for submitting checkout never runs, the button just spins forever.

How to confirm

1. Open Console
2. Reload checkout page
3. Fix the first error you see (ignore downstream ones)

Common causes

• Theme JS bugs
• Minification / defer breaking script order
• Payment gateway scripts failing to load
• Custom snippets injected incorrectly

Quick test:
Disable JS minify/defer in your optimization plugin and retest checkout.

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Check 2: Cached Checkout Page (Stale Nonce Failure)

WooCommerce checkout relies heavily on nonces.
If your checkout page is cached, the nonce can expire—causing the submit to fail silently.

Symptoms:

• Spinner runs forever
• wc-ajax=checkout returns 400
• Response body includes “invalid nonce”

Fix

Make sure checkout is never cached:

• /checkout/
• /cart/
• /my-account/

This is a known WooCommerce requirement and documented in their performance best practices:

If you’re aggressively optimizing, pair this with selectively disabling cart fragments instead of brute-force caching:

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Check 3: wc-ajax=checkout Is Blocked or Failing

On submit, WooCommerce sends an AJAX request to:

?wc-ajax=checkout

If this request:

• Returns 403 → security / firewall
• Returns 400 → nonce or malformed data
• Returns 500 → PHP/server error
• Returns HTML → fatal error or redirect

Checkout will freeze.

How to test

Open Network tab → click Place order → click the wc-ajax=checkout request.

If this request fails, checkout will never complete.

If you’re seeing 400/403 patterns across AJAX endpoints, this post explains it in detail:

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Check 4: Security Plugins or WAF Blocking Checkout

Security tools often:

• Block POST requests
• Block AJAX endpoints
• Flag checkout fields as suspicious
• Rate-limit anonymous users

Admin works because:

• Your IP is trusted
• You’re authenticated

Frontend fails because:

• Guests hit stricter rules

Fix

Whitelist:

• admin-ajax.php
• /wc-ajax/
• /checkout/

If you’re using Cloudflare, disable Bot Fight Mode temporarily and retest.
Cloudflare documents how WAF rules affect AJAX endpoints here:

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Check 5: Hosting-Level Issues (CPU, Memory, mod_security)

Checkout is one of the heaviest operations WooCommerce performs.

Hosting issues that freeze checkout:

• CPU throttling
• Low PHP memory
• mod_security rules blocking POST data
• Slow database writes
• Object cache deadlocks

If checkout freezes under load, or only during traffic spikes, this is a red flag.

Check 6: Payment Gateway Script Failures

If a payment gateway JS fails:

• Stripe
• PayPal
• Square
• Klarna

Checkout may never submit.

Symptoms:

• Error only happens when a specific gateway is selected
• Console error references gateway JS
• Disabling the gateway fixes checkout

Fix

• Update the gateway plugin
• Ensure scripts aren’t deferred
• Test with Cash on Delivery or Check Payments to isolate the issue

WooCommerce explicitly recommends testing with a basic gateway for debugging:This ties directly into high resource usage issues explained here:

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Check 6: Payment Gateway Script Failures

If a payment gateway JS fails:

• Stripe
• PayPal
• Square
• Klarna

Checkout may never submit.

Symptoms:

• Error only happens when a specific gateway is selected
• Console error references gateway JS
• Disabling the gateway fixes checkout

Fix

• Update the gateway plugin
• Ensure scripts aren’t deferred
• Test with Cash on Delivery or Check Payments to isolate the issue

WooCommerce explicitly recommends testing with a basic gateway for debugging:

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Check 7: Cookies, Sessions & SameSite Issues

WooCommerce checkout requires cookies.

Problems happen when:

• Cookie consent blocks Woo cookies
• SameSite rules block cookies
• Checkout runs in an iframe
• Cross-domain setups exist

If sessions break, checkout can freeze or silently reset.

Related deep dive:

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Fix Summary (Run This Top to Bottom)

1. Fix first JavaScript error
2. Disable JS minify/defer temporarily
3. Ensure checkout/cart are not cached
4. Inspect wc-ajax=checkout response
5. Whitelist AJAX endpoints in security/WAF
6. Test with a basic payment gateway
7. Check hosting logs for CPU/memory issues
8. Confirm cookies persist

If checkout works after step 3 or 4, you’ve found the culprit.

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Why This Keeps Happening on WooCommerce Sites

WooCommerce checkout is:

• Dynamic
• AJAX-heavy
• Sensitive to caching and optimization
• Dependent on multiple scripts and cookies

It works great when configured correctly—but breaks fast when treated like a static page.

Understanding this flow saves hours of guesswork.