OpenCart 3 to OpenCart 4 Migration

Migration from OpenCart 3 to OpenCart 4

A real move to the fourth branch — not an in-admin update, but a transfer into a clean installation with everything adapted that will not carry over on its own.

Why this is a separate service, not a "version update"

The architecture changed between the third and fourth branches. Modifications written for OpenCart 3 do not apply in the fourth — their search patterns no longer match. The theme needs rework. Some paid modules simply do not exist for the new branch.

Worth stating separately: OpenCart 4.0 and 4.1 are different platforms. In 4.0 there is no modification mechanism at all; in 4.1 it came back in a different shape. Choosing the sub-version is part of the job, not a detail.

How the work runs

1. Compatibility audit. An inventory of modifications, theme, paid modules and custom code. The output is a list of what will break and an honest answer on whether to migrate at all.
2. Staging. The fourth branch deployed separately from the live store.
3. Data: products, categories, orders, customers and — critically — SEO URLs.
4. Code: theme adaptation, modifications ported to the new mechanisms, modules without compatible versions replaced.
5. End-to-end testing: search, product page, cart, checkout, payment, emails, admin.
6. Cutover with a rollback plan.

What it actually costs

The listed price is a reference point for a store of average complexity. The real figure depends on how many modifications you have and how custom the theme is. I quote precisely after the compatibility audit — it is billed separately and credited towards the migration if you go ahead with it.