Few Magento decisions generate more debate than the frontend stack. Luma, the default theme, is widely criticised but universally compatible. Hyva has become the community favourite by throwing out Luma’s JavaScript stack entirely. Having delivered stores on both, here is the comparison we walk clients through.
The Core Difference
Luma is built on KnockoutJS, RequireJS, jQuery UI and hundreds of JavaScript widgets. A typical Luma category page ships over a megabyte of JavaScript before your own customisations. Hyva replaces all of it with Alpine.js and Tailwind CSS - two small, modern libraries - and rebuilds the templates from scratch. The result is a frontend that routinely scores 90+ on Lighthouse where Luma struggles to reach 40.
Performance in Practice
The gap is real and commercial. We migrated a fashion retailer from a customised Luma to Hyva and saw mobile LCP drop from 4.8 seconds to 1.3 seconds, with a measurable uplift in conversion rate the following month. Core Web Vitals are a ranking factor, so the SEO benefit compounds the conversion benefit.
Extension Compatibility: Luma’s Real Advantage
Every Magento extension ships Luma-compatible frontend code; very few ship Hyva compatibility out of the box. The Hyva compatibility module ecosystem has grown quickly - most major payment, shipping and marketing extensions are now covered - but every third-party module needs checking before you commit. Budget for compatibility work on any extension that renders in the storefront, especially checkout extensions.
Build Effort and Cost
A Luma customisation starts faster because the base templates exist, but the frontend tooling is miserable and performance tuning is endless. Hyva requires rebuilding templates, which costs more upfront for heavily customised designs, but developer velocity afterwards is dramatically better. For a new build, Hyva is usually cheaper over two years. For an existing, deeply customised Luma store, the rebuild cost needs a proper business case.
The Middle Ground
You do not have to go all-in at once. Options we use in practice:
- Hyva with Luma fallback for specific routes while migrating incrementally
- Hyva Checkout on a Luma store - the checkout is where Luma hurts most, and replacing just that route is a contained project
- Breeze theme as a lighter alternative that keeps Luma’s layout but replaces the JavaScript stack
Our Recommendation
For any new Magento 2 or Adobe Commerce build in 2026, default to Hyva unless a hard dependency forces otherwise. For existing Luma stores, start with a Hyva Checkout pilot, measure the conversion delta, and use that data to justify the full rebuild. The performance gap is too large to ignore, but the migration path should be staged and measured, not a big-bang leap.