Merchant Image Audit for WooCommerce — product image audit for the Google Merchant Center 500×500 minimum

Merchant Image Audit for WooCommerce finds product images smaller than 500×500 pixels and shows where a larger original already sits on your site. Google Merchant Center is raising the minimum product image size — image_link and additional_image_link — to 500×500 px for all product categories. Merchant Center has shown the warning “Image too small for upcoming enforcement” since 14 April 2026, and enforcement starts on 31 January 2027. Google says it will optimize some smaller images itself, but it does not say which ones.

A shop that has been importing products for years can have thousands of such images and no way to see them: WordPress shows every picture as a neat thumbnail. The plugin checks every image of every product and tells you which products need attention and what to do about them.

For OpenCart there is a separate version — Merchant Image Audit for OpenCart.

What the plugin does not do. It never enlarges an image and never adds a frame around it: Google’s help does not say enlarged images are accepted, and it asks not to use images with a border. An enlarged small picture is still a small picture. The plugin works only with images that are already on the site.

What the buyer and Google see

The audit runs in the admin and shows nothing to buyers. Buyers only notice the result of the Pro fixes: the product page shows a large main image instead of a blurry thumbnail, and the small one moves to the gallery. Google gets images that pass the minimum — so the product does not get limited because of its image size.

The plugin checks exactly the images Google for WooCommerce sends to Google: the main image (or the first gallery image when there is none) as image_link, the gallery as additional_image_link; a variation without its own image uses the parent’s. It takes the full-size image WordPress serves.

What the admin gets

• One-button audit — WooCommerce → Merchant Image Audit → “Run the audit”. Products are checked in steps with a progress bar; close the tab mid-run and “Continue the audit” picks up where it stopped.
• A verdict for every offer (a simple product or a variation): main image OK; main image too small but a large one is in the gallery; no image large enough; main image unusable (file missing, a format Google does not accept, over 64 megapixels or 16 MB); no image. Plus a separate list of products whose main image is fine but whose gallery has small images.
• Larger originals already on the site. Very often a small product image is a thumbnail (a file name ending in -300×300) that was uploaded or imported as an image of its own, while the full picture is still there. The audit finds the full image with the same name in the media library, the file in the same folder that is not in the media library, and the original of an image cropped in the WordPress image editor (“Restore original image”).
• Images under the recommended size — a separate counter of images that pass the minimum but stay under the 1500×1500 Google recommends.

• Product list with thumbnails, sizes and the reason, filtered by verdict, with a link to edit each product. Works on a phone too.
• A “Google image” column in Products and a box on the product edit screen — you see the problem where you already work with products.
• The list stays current: a product is checked again when it is saved or when one of its images is edited.

• CSV — one line per image: product, SKU, image URL, size, what is wrong and where the larger original is. Problems only or all products; comma or semicolon (for Excel with a decimal comma), with a BOM and formula protection. Hand it to whoever re-shoots or replaces the photos.
• WP-CLI: wp catcode-mia scan, wp catcode-mia summary, wp catcode-mia export file.csv.
• Pro: “Use the larger originals” — the same picture in full size replaces the thumbnail, in bulk or one product at a time with “Use the original”; a file that is not in the media library yet is added to it first. Originals kept by the WordPress image editor are not restored automatically — that would undo a crop.
• Pro: “Large gallery image as the main image” — the first large gallery image becomes the main image and the small one moves to the gallery. Variation images are never swapped (they show the chosen option); a variable product whose variations have small images of their own is left as it is.
• Pro: undo. Before the first change of a product its images are saved, and “Undo” brings them back — in bulk or for one product.

• Pro: Google for WooCommerce, storefront untouched. Send a large gallery image instead of a small main image (for a variation — from the parent’s gallery, the way Google for WooCommerce picks images); leave small images out of additional_image_link; set “Don’t Sync and show” for products with no large image at all — the previous value is kept, and the product is synced again as soon as the audit finds a large image for it. “Sync them again” returns all such products by hand.
• Pro: custom field catcode_gmc_image (ok, fixable, small, bad, none) on every product and variation — for other feed plugins that can filter by a custom field.
• Pro: weekly audit in the background via WP-Cron, with the result and the change since last time by e-mail.

How it works — step by step

1. Install the plugin and open WooCommerce → Merchant Image Audit → “Run the audit”.
2. The plugin goes through published products 25 at a time (configurable) and reads the full-size image size of each offer from the WordPress metadata — the file is opened only when the size is missing. It checks that the file exists, its format and Google’s limits.
3. For every small image it looks for a larger original: in the media library, as a file next to it, in the WordPress image editor backup.
4. It gives every offer a verdict and shows an overview with counters. Clicking a counter opens the list of exactly those products.
5. Next — a CSV for whoever re-shoots the photos, or the Pro fixes: originals, a large gallery image as the main one, Google for WooCommerce settings.
6. After the fixes the list updates itself: a saved or edited product is checked again. Run the full audit as often as you like; in Pro — weekly in the background.

On a test catalogue of 5,050 products the audit took 33–37 seconds on PHP 7.4 and 8.3, with the longest request at 0.4 s. “Use the larger originals” for 2,000 products (importing 1,000 files into the media library) took 5.5 minutes without a single error; undo for 3,000 products took a minute.

Under the hood

• Own tables for the audit results — the audit writes nothing to products or their meta.
• Sizes from the WordPress metadata: a file is read only when WordPress did not store its size, so the audit is fast even on large catalogues.
• AJAX steps instead of one long request: no request runs into max_execution_time, and an interrupted audit continues.
• The media library lookup handles numbered names (item-5 and item-50 are not mixed up) and never imports the same file twice.
• Google for WooCommerce through its own filter woocommerce_gla_product_attribute_values (imageLink and additionalImageLinks) and its visibility meta; tested on both adapters — Content API and Merchant API.
• Undo keeps the previous main image and gallery of a product from before its first change.
• Deleting the plugin removes its tables, settings, meta and cron jobs and gives products their previous Google for WooCommerce visibility back.

How to install

1. Plugins → Add New → Upload Plugin: choose catcode-merchant-image-audit-for-woocommerce-free-1.0.1.zip and activate.
2. WooCommerce → Merchant Image Audit → “Run the audit”.
3. Open the Products tab or download the CSV.
4. For Pro: upload the Pro build over the free one (WordPress offers to replace the installed version) and paste the licence key from the e-mail on the Settings tab — or press “Try Pro for 7 days” there.