Migrating from PrestaShop 1.6 to 8: what breaks and how to avoid it

Migrating PrestaShop 1.6 to 8 is not an update: it is a rebuild. Between those two versions there is a change in architecture, templates, and modules, and anyone who approaches it as if it were just pressing a button ends up with the store down for an entire weekend.

This guide to migrating PrestaShop 1.6 to 8 is about what is sure to break and the order in which it is best to do it, written from the side of the person who then has to fix it.

Why you can’t stay on 1.6

PrestaShop 1.6 has not received security patches for years and runs on PHP versions that are no longer supported. In practice, that means three things: your hosting will eventually force a PHP version your store cannot handle, every new payment gateway will stop offering you a module, and a known vulnerability will not be fixed.

It is not about having the latest version. It is that the ground is being pulled away.

What is sure to break when migrating PrestaShop 1.6 to 8

The theme

There is no theme migration between 1.6 and 8. The template engine changed and so did the front-end structure. Either you rebuild the theme on the new base or you buy a current one. It is the biggest item in the budget and it is worth assuming that from the start.

The modules

The ones from 1.6 do not work in 8. You have to look for the new version of each one, and that is where the real problem appears: abandoned modules do not have a new version. Make the inventory before starting, not halfway through.

Custom modifications

Any override or direct change to the core has to be redone. If back then someone touched core files instead of working with overrides, that part is archaeology.

The URLs

The link structure can change, and that is where rankings are lost. Every URL that changes needs its 301 redirect, and they have to be checked one by one before going live.

Migrating PrestaShop 1.6 to 8 in six steps, in order

1. Inventory. List of modules with their status —has a version for 8, does not have one, no longer needed— and list of customizations.
2. Full backup. Database and files, verified by restoring them somewhere else. A backup you have not tested restoring is not a backup.
3. Test environment. An exact replica with real data where you can do the entire migration without touching the live store.
4. Data migration. Products, customers, orders, and history. Here you check that old orders are still accessible, which is a tax requirement, not a whim.
5. Redirect map. Export the current URLs, compare them with the new ones, and set up 301s for everything that changes.
6. Change window. A low-sales day, with the store in maintenance mode for just long enough and the rollback path ready in case something goes wrong.

How much does it cost to migrate PrestaShop 1.6 to 8

The uncomfortable question. There is no fixed price because the cost is not determined by the catalog, it is determined by the customizations, but there are recognizable ranges.

A standard store, with a purchased theme and up-to-date commercial modules, sits in the lower range: it is mostly about migrating data, setting up the new theme, and redoing configurations. A store with custom developments, ERP integrations, and abandoned modules goes to the higher range, and there the biggest item is not the migration itself: it is rebuilding what was once done by touching the core.

The practical advice: always ask for the budget for migrating PrestaShop 1.6 to 8 to break down the theme, modules, and customizations separately. A fixed price without that breakdown hides the surprises, and in a migration the customer always pays for the surprises.

The five most expensive mistakes

• Migrating directly on production. Without a test environment, the first failure is discovered by a customer.
• Not inventorying the modules first. Discovering halfway through that your gateway module has no version for 8 stops the entire project.
• Forgetting the redirects. It is the number one cause of traffic drops after migrating PrestaShop 1.6 to 8, and it is completely avoidable.
• Jumping all at once from PHP 5.6 to the latest. It is better to go up in steps and check at each one.
• Doing it in peak season. Choose the slowest month of the year, not the one that suits your calendar.

If you want an official reference for the lifecycle and which versions are still receiving maintenance, the project itself maintains it in its system requirements documentation.

What to test before opening the migrated store

• A complete purchase from start to finish, with a real one-cent payment if the gateway allows it.
• Transactional emails: confirmation, shipping, and invoice.
• An old order opened from the back office.
• The search and category filters with the full catalog.
• The connection with your management software, if you have one.
• The redirects, with a sample of the URLs with the most traffic in Search Console.

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If you are also going to review the catalog during the migration, take a look at the product converter and the PrestaShop modules we maintain.

Frequently asked questions

How long does it take to migrate from PrestaShop 1.6 to 8?

Between two and eight weeks depending on the size of the catalog and how many customizations there are. What makes the difference is not the number of products, but the number of custom-made things.

Are old orders lost?

They do not have to be. They are migrated together with customers and invoices. Check that they can be consulted from the new back office before considering the migration valid: the obligation to keep them is still yours.

Is SEO lost when migrating PrestaShop 1.6 to 8?

It is preserved if you do the redirects properly. The typical drop in the first month is recovered if each old URL points with a 301 to its new equivalent.

Is it worth switching to another platform instead of migrating?

If you are going to rebuild the theme and modules anyway, it is a legitimate time to consider it. But changing platforms adds data migration to an already large project: do not do it just because it is trendy.