Astra and Kadence are both lightweight, customizable WordPress themes with free editions and commercial upgrades. The better choice usually depends on the design workflow and ecosystem you prefer.
Design controls
Kadence emphasizes its drag-and-drop header and footer builders and global typography and color controls. Astra provides a flexible theme foundation, broad page-builder compatibility, and a large starter-template ecosystem.
Page builders and blocks
Both themes can work with the WordPress block editor and popular page builders. Choose the theme that integrates most naturally with your preferred builder, template library, and dynamic-content tools.
Ecommerce
Both support ecommerce projects. Review the exact store controls included in the free edition and the commercial module you may need for product layouts, checkout styling, off-canvas features, or advanced headers.
Performance
A lightweight base is useful, but the final result also depends on images, fonts, page-builder output, third-party scripts, plugins, hosting, and caching. Test the complete site rather than relying only on theme marketing.
Decision
Use a staging site to build the same header, product page, blog post, and mobile layout with each theme. The faster and clearer workflow for your real design is usually the more useful answer.