How Do I Upgrade from Plone 4-5 to Plone 6 Without Rebuilding Everything?

Are you still using Plone 4 or 5 CMS and not sure how to move forward?

You’re not alone — many teams hesitate to upgrade because they think it means a full rebuild. But that’s no longer the case.

In this article, I’ll explain how to upgrade to Plone 6 without breaking your current setup, losing custom features, or disrupting your workflow.

Hi, I’m Vitaliy Podoba, founder of SoftFormance and a core Plone contributor. My team and I have been working with Plone since 2005 — back when it was version 2 — and we’ve helped over 80 organizations modernize, migrate, and scale their Plone-based platforms.

Let’s walk through the real, low-risk upgrade path to Plone 6 — the biggest release Plone has seen in years.

Why Upgrade to Plone 6?

There are strong reasons to upgrade to Plone 6:

• Volto, a modern React-based frontend with full REST API integration
• Better user experience for content editors
• Bootstrap 5 styling included out of the box
• Native Dexterity site root support
• Zope 5 backend with Python 3.11 compatibility
• Improved performance, security, and theming options

Plone 6 also retires legacy technologies like Archetypes and portal_quickinstaller, helping future-proof your CMS stack.

Common Misconceptions About the Upgrade

The biggest misconception is that “upgrading to Plone 6 means starting from scratch.” This is not true.

If you’re using Plone 5.2 or newer, you can upgrade in place. You’ll run the plone-upgrade view, migrate your ZODB database, and your existing content and permissions will stay intact.

However, there are some changes to expect:

• Your site root may appear empty after upgrade — this is resolved by completing the Dexterity root migration.
• Archetypes-based content types are no longer supported, so they must be converted to Dexterity.

How a Real Upgrade Works?

Here’s how we approach upgrades at SoftFormance:

Step 1: Audit Your Current System:

• Identify your current Plone version
• List all third-party add-ons
• Review custom templates and JavaScript (especially Barceloneta-based themes)

Step 2: Plan Your Frontend Strategy

You have two frontend options:

• Volto: A modern, decoupled React UI using REST API
• Classic UI: Server-rendered, legacy option still supported

Note: Do not install plone.volto if you intend to use Classic UI — they cannot coexist.

Step 3: Upgrade the Backend

• If you’re on 5.2, you’re already on Python 3. Otherwise, migrate first
• Plone 6 removes portal_quickinstaller and temp_folder, so check compatibility
• Replace deprecated code like ustring with string
• Run plone-upgrade and verify that database migrations completed

Step 4: Upgrade Add-ons

• Most modern add-ons now use plone.autoinclude instead of z3c.autoinclude
• Some deprecated packages, like collective.dexteritytextindexer, are now part of Plone core
• Update template overrides for Bootstrap 5 changes

Step 5: Modernize the UI (Optional)

• If switching to Volto, follow the official migration guide
• Replace outdated view aliases
• If staying with Classic UI, consider creating a fresh Barceloneta-based theme

When You Shouldn’t Upgrade (Yet)

Consider delaying your upgrade if:

• Your site heavily relies on Archetypes
• You depend on outdated or unsupported add-ons
• You don’t have in-house Plone expertise

In such cases, we often recommend a partial upgrade of the backend first, rebuilding critical parts in Volto, or migrating in stages.

Need Help? We Offer a Free Audit

Not sure whether to upgrade or rebuild? We can help.

Our team at SoftFormance offers a free Plone CMS audit. We’ll:

• Analyze your current version, add-ons, and customizations
• Identify the best migration path and any risks
• Help you decide between Volto and Classic UI
• Provide a phased roadmap and cost estimate

Click the link to request your free audit.

Let’s future-proof your Plone system — without unnecessary risk or cost.

Thanks for reading. If this article helped you, feel free to reach out.

See you next time!