Does the customer keep the same quantity after the change?

Yes. The new combination takes over the line quantity, delivery address and position in the cart. If the chosen combination was already in the cart, both quantities are added up on a single line.

What happens if the new combination does not have enough stock?

If out of stock ordering is not allowed for the product, the module refuses the swap and shows the number of units available. The original line stays as it was. In the window, out of stock combinations are greyed out or hidden before the customer even clicks.

Does the module work with my theme?

The module uses the displayCartExtraProductActions hook found in the cart of the Classic theme and most themes built on it. If your theme does not call it, the script places the button using the remove links of the lines. Test on a copy of your shop, especially with a heavily customized theme.

Can the combination of a customized product be changed?

Not in version 1.0.0. Lines that carry a customization (engraved text, uploaded file) keep their combination, because the customization is attached to the original combination. The button does not appear on those lines.

Does the module edit core or theme files?

No. No override, no template edit. The module hooks into two native hooks and loads one CSS file and one JavaScript file on the cart page only.

PrestaShop Checkout & Payment

Change Product Variant in Cart for PrestaShop 8 & 9: Edit Size and Color Without Removing the Product

Customers change size or color without leaving the cart.

In PrestaShop, a customer who wants an M instead of an S has to remove the line, find the product page again, pick the right size and add it to the cart once more. Some customers give up at that point. With this module, a "Change" button on each line opens a window with the sizes, color swatches, combination image, price and stock. One click on "Update cart" and the line is replaced, in the same place, with the same quantity.

At a glance

"Change" button on each cart line, or dropdown lists right in the line
Color swatches, size buttons, image, price and price difference per combination
Stock and minimum quantity checked server side before the swap
Quantity, delivery address and line position kept
Change history and share of edited carts that became orders

PrestaShop 8 & 9 Cart No override 8 languages

30-day refund
12 months updates
24h support

www.datafirefly.com/en/

Change Product Variant in Cart for PrestaShop 8 & 9: Edit Size and Color Without Removing the Product

v1.0.0 · updated 2026-10-13

What it does

The short version.

Customers fix their size without starting over

The Change button opens a window with the product attribute groups, in your catalog order: swatches for colors (textures included), buttons for sizes, a dropdown for groups with more than 8 values. The image of the selected combination shows at the top, with its price and the difference from the current line. On mobile, the window slides up from the bottom of the screen.

No impossible combination

If the customer picks Blue while M Blue does not exist, the module switches to the existing combination that keeps the most current attributes, an orderable one first. Values without stock are greyed out or hidden, depending on your setting. PrestaShop stock management and out of stock ordering are respected.

A swap checked server side

Before touching the cart, the module checks that the combination belongs to the product and the shop, that stock covers the quantity and that the minimum quantity is reached. It adds the new combination before removing the old one, and rolls back if something fails. If the chosen combination is already in the cart, quantities are merged.

The cart refreshes as usual

After the swap, the module fires the native PrestaShop updateCart event: the line, totals, cart rules and header mini cart update without a reload. If the theme does not react to this event, the page reloads to show the right cart.

The long version

Everything you'd want to know before you install.

A detailed look at how Change Product Variant in Cart for PrestaShop 8 & 9: Edit Size and Color Without Removing the Product works, why we built it the way we did, and the thinking behind the features above.

§ 01

Why the PrestaShop cart stalls on a simple size change

The native cart lets customers change the quantity or remove a line, nothing more. To go from an S to an M, the customer has to remove the product, go back to its page, find the right combination and add it again. On mobile, that is four or five screens for a one second fix. This module adds the missing step: change the combination where the customer already is.

§ 02

Two layouts depending on your shop

The window mode suits fashion, footwear or home decor shops: the color is picked on a swatch and the image follows the selection. The dropdown mode suits technical or B2B catalogs, where the customer wants to switch a reference in one move from the line. In that mode, the theme's native attribute rows are hidden to avoid showing them twice.

§ 03

A swap that follows your shop rules

The module goes through the PrestaShop cart methods (updateQty and deleteProduct), not through direct queries on cart lines. Automatic cart rules, specific prices and minimum quantities apply as they do for a normal add to cart. Lines tied to a gift cart rule are refused with a message, so a running offer is not broken.

§ 04

Measure what the feature brings

Each change is logged with the cart, the product, the starting combination and the chosen one. The configuration page shows the number of changes over 30 days, the number of carts concerned, how many became orders, the most changed products and the last 20 changes. A product often changed from S to M points to a size guide worth reviewing.

Everything included

The long list.

Customers fix their size without starting over — The Change button opens a window with the product attribute groups, in your catalog order: swatches for colors (textures included), buttons for sizes, a dropdown for groups with more than 8 values. The image of the selected combination shows at the top, with its price and the difference from the current line. On mobile, the window slides up from the bottom of the screen.

No impossible combination — If the customer picks Blue while M Blue does not exist, the module switches to the existing combination that keeps the most current attributes, an orderable one first. Values without stock are greyed out or hidden, depending on your setting. PrestaShop stock management and out of stock ordering are respected.

A swap checked server side — Before touching the cart, the module checks that the combination belongs to the product and the shop, that stock covers the quantity and that the minimum quantity is reached. It adds the new combination before removing the old one, and rolls back if something fails. If the chosen combination is already in the cart, quantities are merged.

The cart refreshes as usual — After the swap, the module fires the native PrestaShop updateCart event: the line, totals, cart rules and header mini cart update without a reload. If the theme does not react to this event, the page reloads to show the right cart.

"Change" button per line opening a selection window

Alternative mode: dropdown lists in the line, applied as soon as they change

Color swatches and attribute textures, buttons for sizes, dropdown for groups with more than 8 values

Group and value order taken from the catalog

Combination image, price with or without tax according to the customer group, strikethrough price on discounts

Price difference shown against the current line

Stock status: in stock, only X left (PrestaShop threshold), backorder, out of stock

Unavailable combinations greyed out or hidden

Automatic switch to the closest existing combination

Server side check of stock, minimum quantity, shop and token

Add before remove, with rollback if the operation fails

Quantities merged if the chosen combination is already in the cart

Quantity, delivery address and line position kept

Refresh through the native updateCart event, reload as a fallback

Automatic placement under the line attributes, can be turned off

JavaScript fallback for themes that do not call the displayCartExtraProductActions hook

Excluded products by ID

Adjustable accent color

Keyboard navigation, accessible window (dialog role, Escape, focus)

History: changes over 30 days, carts concerned, carts that became orders, most changed products

actionDfCartCombinationChange hook for your own processing

Module translated into English, French, Spanish, German, Italian, Dutch, Polish and Portuguese

No override, no Composer dependency

€89.00

One-time · 12 months updates

Read the docs

Unlimited dev & staging installs
Source code included
30-day refund
24h support · EN / FR

5.0/5 19 reviews

giuliano 9 October 2026 ★★★★★

“very useful module, with the bulk matching we restored the catalogue after importing from WooCommerce where we only had one image per variation, then just had…”
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giuliano stellac 2 October 2026 ★★★★★

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Giuliano 30 July 2026 ★★★★★

“Exceptional technical support, fast, available and knowledgeable.”
DataFirefly Mega Menu & Burger

Change Product Variant in Cart for PrestaShop 8 & 9: Edit Size and Color Without Removing the Product

The short version.