BigCommerce's Blueprint theme framework is being phased out. It is no longer supported or updated by BigCommerce. For merchants still running Blueprint storefronts, migration to Stencil isn't a feature upgrade decision — it's a maintenance requirement.
The good news is that Stencil is a meaningfully better architecture, and the migration delivers measurable performance improvements alongside the platform support continuity.
Blueprint vs. Stencil: The Performance Difference
The performance gap between Blueprint and Stencil is significant and objectively measurable. In comparative testing:
- Desktop PageSpeed: Stencil scores approximately 90; Blueprint approximately 79
- Mobile PageSpeed: Stencil scores approximately 74; Blueprint's mobile score is effectively unavailable as the framework lacks proper mobile optimization
- Google AMP support: Stencil supports it; Blueprint does not
- Akamai Image Manager integration: Stencil supports it; Blueprint does not
For merchants concerned about Core Web Vitals performance and its effect on search ranking, Blueprint is a structural disadvantage that no amount of optimization can overcome within the framework's constraints.
What Stencil Actually Is
Stencil is BigCommerce's current native theme framework. Key characteristics:
- Mobile-responsive by design. Built with responsive layouts from the ground up rather than adapted from a desktop framework.
- Handlebars.js templating. More modern and maintainable than Blueprint's template language.
- Built-in performance features. Image optimization, lazy loading, and CDN integration are part of the framework rather than additions.
- Customizable without custom code. The Theme Editor in BigCommerce's admin allows visual customization without requiring a developer for routine changes.
- Theme Store compatibility. Current BigCommerce theme marketplace themes are Stencil-only. Blueprint merchants can't access new themes.
What Migration Involves
Blueprint-to-Stencil migration isn't a settings toggle — it's a theme replacement. The process:
Theme selection or design. Either select an existing Stencil theme from the BigCommerce theme marketplace (and customize it to match your brand) or build a custom Stencil theme from your current design.
Template migration. Custom functionality built in Blueprint templates needs to be rebuilt in Stencil's templating system. The extent of this work depends on how heavily the Blueprint theme was customized.
Content and asset review. Images, custom HTML content blocks, and other content tied to Blueprint-specific template features need to be reviewed and migrated or recreated.
Integration verification. Third-party integrations and apps that relied on Blueprint-specific template hooks need to be verified against Stencil.
Testing. Full transactional flow testing — from product browse through checkout and order confirmation — before go-live.
The Catalyst Option
For merchants doing a Blueprint migration who are also evaluating their longer-term architecture, BigCommerce Catalyst — the headless Next.js storefront framework — is worth evaluating at the same time. Catalyst achieves higher Core Web Vitals scores than Stencil and provides frontend independence from the BigCommerce release cycle. See the Catalyst overview for details.
Arizon Digital has executed Blueprint-to-Stencil migrations for BigCommerce merchants — including custom theme development, template migration, and integration verification. Talk to us about what a Blueprint migration timeline looks like for your store.