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What We Found Inspecting Public Shopify Storefronts: PostBoost HTML Teardown

Audit your Shopify storefront HTML for PostBoost post-purchase upsell gaps using this teardown checklist.

Oct 21, 2026PostBoost Team

Quick Verdict (TL;DR) Post-purchase upsells can boost AOV, but many Shopify stores miss them due to HTML or gateway issues. Use this teardown checklist to verify your storefront before changing apps or theme settings.

You installed a post-purchase upsell app, but offers never appear. Or you see them in testing but not in production. The hidden cost: lost revenue from every missed upsell, plus wasted time debugging. Common culprits include incompatible payment gateways, multiple post-purchase apps conflicting, or theme customizations that break the checkout extension. Without a systematic audit, you're guessing.

What to check first

First-party public HTML inspection across 2 sampled storefront(s) (4 public page(s) checked) surfaced recurring patterns in: post_purchase (4 storefront sample(s)). Review Shopify Post-Purchase Checkout Extension requirements: the offer page appears after initial payment is authorized and before the Thank You page, requires a compatible gateway such as Shopify Payments, and only one post-purchase app can be selected as active in Shopify Checkout settings. Use these anonymized public-HTML observations to explain how merchants can verify their own storefront markup before changing apps or theme settings.

Side-by-side comparison

Aspect Status Quo (No Audit) PostBoost with Audit
Offer visibility Unpredictable; may not show Verified via HTML inspection
Gateway compatibility Assumed, often wrong Checked against Shopify requirements
App conflicts Multiple apps active, causing failures Only one post-purchase app active
Commission fees Varies by app, often 10-20% 0% commission, flat monthly fee
Debugging time Hours of trial and error Structured checklist pinpoints issues
Customer experience Broken or missing offers Seamless 1-click upsell after payment

How to work through it

  1. Check your payment gateway: Post-purchase offers require Shopify Payments or a compatible gateway. In Shopify admin, go to Settings > Payments and confirm your primary gateway supports post-purchase. If not, offers won't display.

  2. Verify only one post-purchase app is active: In Shopify admin, go to Settings > Checkout > Post-purchase upsell. Ensure only PostBoost (or your chosen app) is selected. Multiple apps cause conflicts.

  3. Inspect your live storefront HTML: Use browser developer tools (F12) on your product and checkout pages. Look for post-purchase related scripts or meta tags. Missing or malformed tags may indicate theme conflicts. Compare against a clean Shopify theme.

  4. Test a real transaction: Place a test order using Shopify's test payment gateway (or a real transaction with a refund). After payment, confirm the post-purchase offer page appears before the Thank You page. If not, check for JavaScript errors in the console.

  5. Review theme customizations: If you use a custom theme, ensure it doesn't override checkout extensibility. Check for outdated snippets or hardcoded checkout scripts. Consult your theme developer if unsure.

  6. Document findings: Note any missing elements, errors, or gateway issues. Use this to decide whether to adjust settings or switch apps.

Where the product fits

PostBoost is built for Shopify merchants who want to add 1-click post-purchase upsells without commission fees. It uses the official Shopify Post-Purchase Checkout Extension API, so it requires Shopify Payments or a compatible gateway. Only one post-purchase app can be active at a time. PostBoost is not a fit if you use an incompatible gateway or need multiple post-purchase apps simultaneously.

Next step

Ready to fix your post-purchase upsell gaps? Start your audit with PostBoost at https://postboost.getsearivo.com.

Frequently asked questions

Why isn't my post-purchase offer showing up?

Common reasons: incompatible payment gateway, another post-purchase app active, or theme conflicts. Check your gateway and app settings first.

Can I use PostBoost with any Shopify plan?

PostBoost requires a Shopify plan that supports checkout extensibility (typically Basic or higher). Also, your gateway must support post-purchase offers.

How do I switch from another post-purchase app to PostBoost?

First, deactivate the other app in Shopify Checkout settings. Then install PostBoost and set it as the active post-purchase extension. Test thoroughly before going live.

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