PS PrestaShop PrestaShop Beginner

Automatic Product Image Watermark — Complete Guide

Install, configure and use the automatic product image watermark: PNG logo and text modes, opacity, percentage size, 9 positions and tiled, JPG/PNG/WebP/AVIF formats, thumbnail regeneration and best practices for PrestaShop 8 and 9.

Updated Module version 1.0.1

Overview

The Automatic Watermark module stamps your logo or your name onto your product image thumbnails, with no manual work. The watermark is applied as soon as an image is added to a product and on every thumbnail regeneration. The key point: your original files are never modified. Only the per-image-type variants (large, home, category, etc.) are stamped, which guarantees that a fresh regeneration always starts from a clean source.

The module offers two modes — a transparent PNG logo or text — with fine control over opacity, size, position and the formats processed. It is compatible with PrestaShop 1.7, 8 and 9, and only requires the PHP GD extension, present on virtually every host.

Installation

  1. In the back office, open Modules > Module Manager.
  2. Click Upload a module and drop in the module’s ZIP archive.
  3. Once installation is complete, click Configure.

On install, the module registers the actionWatermark hook and applies ready-to-use defaults (60% opacity, bottom-right position, logo size at 25% of the width, all image types selected). The GD extension is checked: if it is missing, installation is aborted with an explicit message.

Configuration

The configuration page is organised into three panels: Watermark type, Appearance & position and Application. A preview of the currently uploaded logo is shown at the top of the page, along with a direct button to the thumbnail regeneration.

Watermark type

  • Mode — choose between Logo (PNG image) and Text.
  • Watermark logo — upload your image (transparent PNG recommended, 4 MB maximum). The file is converted to PNG to preserve transparency. Leave this field empty to keep the current logo.
  • Delete logo — tick this box to remove the saved logo.
  • Watermark text — the text to embed in Text mode (shop name, copyright, URL…).
  • Text colour — the text colour, in Text mode.

Appearance & position

  • Opacity (%) — from 1 (very transparent) to 100 (opaque).
  • Logo size (% of image width) — the logo width expressed as a percentage of the image width. A value of 0 keeps the logo’s native size. Expressing the size as a percentage lets the watermark keep consistent proportions across every image format, from the large product page to the category thumbnail.
  • Text size (% of image width) — same principle, for Text mode.
  • Text angle (°) — text tilt, in Text mode.
  • Position — nine anchors (top/middle/bottom × left/center/right) or the Tiled mode, which repeats the watermark across the whole image.
  • Horizontal and vertical margins (px) — the gap in pixels from the edge, for anchor positions.
  • Tile spacing (%) — the gap between repetitions, used only with the Tiled position.

Application

  • Minimum width (px) — images narrower than this value are not watermarked. This avoids stamping micro-thumbnails (cart, search), where a watermark would be unreadable.
  • Image types to watermark — select the relevant image types (large_default, home_default, etc.). Each type shows its dimensions to help you choose.
  • Formats to process — JPG, PNG, WebP and AVIF. Select the formats generated by your shop. PrestaShop 8 and 9 often produce WebP and AVIF in addition to the main format.

After every change, remember to save, then regenerate thumbnails to apply the new settings to images already online. Newly uploaded images are watermarked automatically with the current settings.

How the watermark works

The module hooks into PrestaShop’s native actionWatermark hook, triggered on every (re)generation of a product image’s thumbnails. For each selected image type and each active format, the module loads the generated thumbnail, applies the watermark, then resaves the file reusing the quality levels defined in your shop’s image settings.

Only the per-image-type variants are processed: the original file stays intact. You can therefore change the watermark and regenerate as often as you like without ever degrading the source.

In logo mode, your PNG’s transparency is preserved thanks to a custom alpha-merge that combines the global opacity you set with the image’s native transparency. No frame or opaque background is added around the logo.

Applying the watermark to existing products

The hook only processes an image at the moment it is generated. To watermark a catalogue already online, run a thumbnail regeneration:

  1. Open Design > Image Settings (a direct button is available on the module page).
  2. Run the thumbnail regeneration for product images.

Regeneration recreates the thumbnails from the originals, then the module applies the watermark to them. On very large catalogues, prefer PrestaShop’s native regeneration, designed to handle large volumes. Regeneration is also available from the command line:

bin/console prestashop:thumbnails:regenerate products

Logo mode or text mode

Logo mode suits you if you have a strong visual identity: a transparent PNG placed bottom-right at 60% opacity is enough to sign your visuals without disturbing the product.

Text mode is ideal for a quick notice without preparing a file. The DejaVuSans font is bundled with the module, which guarantees identical rendering on every host, independent of the fonts installed on the server.

Compatibility

  • PrestaShop — 1.7, 8.x and 9.x. The 9.x compatibility covers the new Symfony-based regeneration: the module resolves its file paths defensively to work even when legacy constants are not loaded.
  • PHP — 7.2 and above, with the GD extension.
  • Formats — JPG, PNG, WebP and AVIF, as well as high-density @2x variants. Processing WebP and AVIF depends on those formats being supported by the server’s GD library.

Uninstallation

Uninstalling removes the module’s configuration and its hook. Watermarks already applied remain on the thumbnails until the next regeneration. To get watermark-free images back, uninstall the module then regenerate thumbnails: they start again from the original files, which remained intact.

Troubleshooting

The watermark is not being applied. Check that at least one image type and one format are ticked in the Application panel, that a logo is indeed uploaded in logo mode (or text entered in text mode), and that the minimum width does not exclude the target image type. Then run a thumbnail regeneration.

  • The logo appears too small or too large — adjust the Logo size (as a % of the width), or set it to 0 to keep the native size.
  • WebP or AVIF not watermarked — the server must have a GD library compiled with support for those formats. If not, the relevant files are simply skipped, with no error.
  • Watermark on tiny thumbnails — increase the Minimum width to exclude small formats.

FAQ

Are my original images modified?

No. Only the thumbnails generated per image type are watermarked. The original file stays intact.

How do I apply the watermark to products already online?

Configure the module, then run a thumbnail regeneration from Design > Image Settings. Newly uploaded images are watermarked automatically.

Does the module work with WebP and AVIF?

Yes, as well as with @2x variants, provided the server’s GD extension supports those formats.

Do I need to prepare a file for text mode?

No. You simply type the text; the font is bundled with the module.

Is my PNG logo’s transparency preserved?

Yes, thanks to a custom alpha-merge that preserves transparency while applying the chosen opacity.

Is the module compatible with PrestaShop 9?

Yes, the module is compatible with PrestaShop 1.7, 8 and 9, including the new Symfony-based regeneration.

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