Stencil is BigCommerce’s current theme platform that incorporates the latest best practices in technology, design standards, conversion, and SEO. A common misconception is that Blueprint and Stencil are just different styles of BigCommerce theme. In fact, the differences between them are much deeper. Stencil and Blueprint are different frameworks.
A framework is the foundational code base that a website is built on. It’s like the engine that powers a car. Stencil outperforms Blueprint because its “engine” (code base) is better.
As stated by BigCommerce, “Blueprint, our legacy theme framework, was built on a rigid, proprietary codebase, making it difficult for developers to customize and extend theme functionality. Stencil themes are built on non-proprietary, open-source code to minimize the learning curve for developers and to provide access to the best developers in the industry.”