Pimcore Classic UI Is Being Retired.

Here's where most teams underestimate the impact.

1. Your custom extensions will break

If you've built any custom functionality in the Pimcore admin - and most production deployments have - it was written in ExtJS. Custom grid columns, specialized editors, admin plugins, workflow buttons, dashboard widgets. All of it sits on top of ExtJS controllers and components.

In Pimcore Studio, those ExtJS controllers need to be rewritten as React components or REST endpoints. Pimcore provides a plugin SDK with a migration CLI that can convert approximately 70% of boilerplate code automatically, but the remaining 30% - your actual business logic - requires manual migration.

The longer you wait, the more custom code accumulates on the deprecated stack.

2. The licensing landscape has shifted

Alongside the UI change, Pimcore moved from GPLv3 to the Pimcore Open Core License (POCL) starting with version 2025.1.

Key implications:

• Companies with >EUR 5M annual revenue must purchase a commercial license (Professional or Enterprise Edition) to use Pimcore 2025.1+
• If you stay on Classic UI (Community Edition), you now need a separate ExtJS perpetual license for EUR 1,480 due to Pimcore's OEM agreement with Sencha
• Pimcore Studio is included in all editions (Community, Professional, Enterprise) - no additional UI license needed

So staying on Classic UI actually costs more and gives you less. The incentive structure is clear: move to Studio.

3. Security support has a hard deadline

Pimcore 11 (the last version with Classic UI as the primary interface) lost Community Edition support in autumn 2025. Platform 2025.4 with LTS support runs until end of 2028 - but only for security and maintenance patches, not new features.

After 2028, if you're still on 2025.4 with Classic UI, you're running an unsupported platform on deprecated frontend technology with no vendor backing. That's not a technology choice - it's a liability.

4. Your development velocity will stall

ExtJS is not a technology modern developers want to work with. Finding experienced ExtJS developers in 2026 is increasingly difficult. The React/TypeScript ecosystem, on the other hand, has the largest developer community in the world.

By migrating to Studio, you unlock:

• A codebase that junior and mid-level developers can navigate
• Modern testing (Jest, React Testing Library) instead of zero test coverage
• Component-based architecture that's easier to maintain and extend
• Hot module replacement and proper build tooling for faster development cycles
• Access to the entire React/Ant Design component ecosystem

This directly translates to faster feature delivery and lower maintenance costs.

The window is clear:

• 2025.4 LTS is your safe harbor - it supports both UIs and is covered until end of 2028
• Studio 1.0 is feature-complete for editors and admins (end of Q1 2026)
• 2026.1 drops Classic UI entirely (end of March 2026)

If you start now, you have time to migrate methodically. If you wait until 2027, you'll be migrating under pressure with a shrinking support window.

The migration is not optional. It's not a matter of "if" but "when." And the organizations that treat it as an operational improvement project - not a panic-driven UI swap - will come out ahead.