PrestaShop 9 Complete Guide: New Architecture, New Theme, What's Missing

PrestaShop 9 officially launched on June 6, 2025, after nearly two years of development. For the PrestaShop community — home to over 250,000 active online stores — this is the most significant platform update since the move from version 1.7 to 8. It is a genuine architectural overhaul: a modernised technology stack, a brand-new default theme, a completely new Admin API, and a foundation designed for the next decade of ecommerce.

In March 2026, PrestaShop 9.1 followed with Hummingbird 2.0 as the default storefront theme and two new experimental features. This guide covers what arrived, why it matters, and what the roadmap still needs to deliver.

Part 1: Why PrestaShop 9 Is a Big Deal

The jump from PS8 to PS9 is best understood as a platform modernisation project, not just a feature release. The core team spent two years replacing ageing technical foundations with modern equivalents — upgrading the framework, API layer, front-end theme system, and developer toolchain all at once. For everyday store owners the most visible changes are speed and the new Hummingbird theme. For developers, it is the new Admin API and modernised codebase.

PrestaShop powers over 250,000 online stores globally. The majority run in Europe — France, Spain, Poland, and Latin America are especially strong markets. Version 9 represents the platform's biggest architectural commitment since 2017.

Part 2: Symfony 6.4 LTS — The New Technical Foundation

PrestaShop 9 is built on Symfony 6.4 LTS — a major leap from the Symfony 4.4 that powered PS8.

• Security support guaranteed through at least November 2027
• Faster code execution and reduced memory usage versus Symfony 4.4
• Access to modern Symfony features enabling cleaner module and integration development
• Better alignment with the PHP ecosystem — easier to hire developers and find compatible tooling

Part 3: PHP 8.1 to 8.4 Support

PrestaShop 9 requires PHP 8.1 minimum and supports through PHP 8.4 (PHP 8.3 recommended for production in 2026). PrestaShop 9.1 adds PHP 8.5 compatibility. Running PS9 on PHP 8.3+ delivers measurably faster response times and better memory efficiency compared to the PHP 7.x environments many legacy PS installations still use.

Server check: If your hosting still runs PHP 7.x, upgrading to PS9 requires a server environment upgrade first. Most modern managed hosts support PHP 8.3+ out of the box.

Part 4: New Admin API — Opening the Door to Headless Commerce

The most strategically significant addition in PS9: a brand-new Admin API built on API Platform with OAuth 2.0 authentication. This replaces the old approach of direct database access, legacy web services, or complex module hooks.

• Build headless storefronts using PrestaShop as a backend commerce engine with a custom front end
• Integrate cleanly with ERP systems, PIM platforms, and inventory management tools
• Power mobile apps and progressive web apps (PWAs) with clean API access
• Enable B2B portals, wholesale ordering systems, and custom checkout flows

The API was introduced in PS9.0 with some endpoints still in development. PS9.1 expanded coverage and improved stability. Continued Admin API development is a stated priority for 9.x releases throughout 2026 and 2027.

Part 5: Hummingbird Theme — A Modern Default Storefront

PrestaShop's old Classic theme was introduced with PS 1.7 and had not been substantially updated since — dated, poor mobile performance, and difficult to customise cleanly. Hummingbird replaces it entirely and became the default with PS9.1.

• Bootstrap 5.3.3 with proper dark mode support and a stable API for child themes
• BEM-based CSS for easier overrides without specificity conflicts
• TypeScript in the front office for type-safe JavaScript development
• SCSS with CSS @layer for modular, scalable styling architecture
• WebP and AVIF support baked in for optimised Core Web Vitals
• 95%+ EAA compliance — the European Accessibility Act (mandatory for EU stores from June 2025). Semantic HTML, ARIA attributes, keyboard navigation, and sufficient colour contrast built in from the ground up
• SEO-optimised structure with structured data and clean semantic HTML

For theme builders: Hummingbird is not backward-compatible with Classic-based child themes. New theme development in 2026 should start from Hummingbird. Classic themes still work on PS9 but won't benefit from the new architecture.

Part 6: Admin Back Office Modernisation

Beyond the new API, PS9 includes an extensive refresh of the admin interface: improved mobile responsiveness, better navigation and visual hierarchy, modernised UI components, and noticeably faster performance across catalog management and order processing — all thanks to the Symfony 6.4 upgrade.

Part 7: Performance Improvements

Early benchmarks comparing identical stores on PS8 vs PS9 show measurable improvements. The combination of Symfony 6.4, PHP 8.3+, and the optimised Hummingbird theme creates a noticeably faster storefront.

• Reduced memory usage from the Symfony 6.4 upgrade
• WebP/AVIF support in Hummingbird reduces image payload sizes significantly
• Leaner front-end JavaScript (jQuery deprecated in Hummingbird in favour of vanilla JS)
• Cleaner code execution paths from removal of legacy compatibility layers

Part 8: PrestaShop 9.1 — Hummingbird 2.0 and Experimental Features

Released March 2026, PS9.1's headline change is Hummingbird 2.0 becoming the default theme. It also introduces two experimental features behind feature flags:

Multi-Carrier Shipping: Assign different carriers to individual items within the same order — long-requested for stores shipping from multiple warehouses or using different fulfilment methods for different product categories.

Redesigned Discount System: A more flexible discount architecture making complex promotional rules easier to create and manage. The legacy system had significant limitations around stacking rules and customer segment targeting.

Part 9: What PrestaShop 9 Still Needs

• Incomplete Admin API coverage: Not all back-office endpoints are available yet — fully headless implementations still encounter gaps
• Module ecosystem compatibility debt: Symfony 4.4 → 6.4 plus PHP 8.x creates significant challenges. A complex store with 20+ modules could take 1–3 months to migrate
• No native page builder: Building custom landing pages still requires developer work or third-party modules
• Zero native AI features: No AI product descriptions, smart search, or automated SEO in core. Competitors like Shopify and BigCommerce are ahead here
• Thin B2B features: Quote management, company account hierarchies, and RFQ workflows remain largely module-dependent
• Multi-carrier shipping still experimental: Merchants needing this for production must wait for it to graduate to stable
• Checkout modernisation incomplete: The default checkout UX still underperforms vs one-page checkout experiences modern shoppers expect

Part 10: Should You Migrate?

New stores should start on PS9 — there is no reason to build on a version receiving no new features. Existing PS8 stores should plan a migration timeline: audit modules, assess custom theme requirements, and budget developer time. PS8 receives security patches through early 2027, so there is no emergency — but the gap widens every month you wait.

Conclusion

PrestaShop 9 rebuilds the platform on foundations that will support the next decade of ecommerce. Symfony 6.4 LTS, PHP 8.x support, the new Admin API, and Hummingbird collectively represent a genuine modernisation — not a cosmetic one. The gaps are real (incomplete API, absent AI, thin B2B), but the direction is right. For merchants evaluating PrestaShop in 2026: version 9 is the platform to build on.