Optimizely CMS 11 support has ended - Here's what that means for you
Optimizely CMS 11 is no longer supported. The newer version, CMS 13, became available at the end of March 2026, and Optimizely only supports the two most recent versions at any time - so CMS 11 dropped out of support on 10 April 2026. We recommend starting to plan the move to CMS 13 now, before the gap between your site and the supported version grows any wider.
Key dates:
CMS 13 became available: 31 March 2026
CMS 11 support ended: 10 April 2026
Support policy: only the two most recent versions are supported at any time
What you should do: Start planning the upgrade now
What "no longer supported" actually means:
Your website won't stop working. It will keep running exactly as it does now. What stops is the safety net underneath it - if a security issue is ever found, it won't get fixed. There's no set date when your site will suddenly break, but the longer it stays on an unsupported version, the more exposed it becomes.
Why this upgrade isn't as simple as it sounds:
Moving from one version of the CMS to another is a well-understood process: Optimizely has clear steps for that part, so it's low-risk. The real work is in everything that's been built around your website over the years: custom features, connections to other systems (like your customer or product database), and custom tools your team uses behind the scenes. These were built specifically for your site, so when the technology underneath changes, they often stop working and need to be individually checked and rebuilt. That's where most of the time and effort actually goes, not the upgrade itself.
Where the effort actually goes:
The technical foundation. The system your website is built on needs a significant update behind the scenes. This is usually the single biggest piece of work in the whole upgrade, and it's easy to underestimate because it's invisible to anyone using the site day to day.
Search and related content features. If your website has a search bar, autocomplete, filtering, or "related pages" type features, these will likely need to be rebuilt using a newer system.
Custom-built tools and admin screens. Any tools built specifically for your team will likely need rework to function in the new version. It's also a good opportunity to retire any tools nobody actually uses anymore.
What you gain:
This isn't just about staying supported — there are real upsides too:
A better content editing experience. The newer version comes with an improved way for your team to build and manage pages, giving more control over layout. It works best if your content structure is reorganised at the same time, rather than just carried over as-is.
A more modern, secure foundation overall. Once the technical update is done, everything the site is built on is simply more current and easier to build on going forward.
How we'd plan it:
Check what's involved before setting a budget. The real cost depends on what's been custom-built around your site, not the upgrade itself. A short review of your site's add-ons, custom features, search, and integrations gives you a much more accurate picture.
Test the riskiest parts first. Before committing to a full plan, it's worth trialling the trickiest pieces — the technical foundation update and the search rebuild — on a small part of the site first.
Treat the content structure as part of this project, not something to sort out later.
Next Step?
Get in touch with us and we'll help you plan the move from CMS 11 to CMS 13 for your site.
Dov Tombs
Managing Director – APAC
