The filename of your Shopify product images

Two things decide whether a product image turns up in a search: its dimensions and its alt text, both already covered on this blog. There is a third piece, quieter, and it survives every transformation Shopify’s CDN applies to the file: the filename itself.

What a generic filename gives away

Open the media library of any Shopify store, and a good share of the filenames look like this:

These are the metadata a camera or a piece of software picked for you, not a description of your product. The free PixelUnik audit recognises these names automatically, from verifiable shapes like the ones above: camera prefixes, digit-only names, hexadecimal ids, filler words. Nothing subjective about it.

Why it matters

A filename is text, readable before the image content is analysed at all. It is one of the few signals a search engine can read without guessing anything. A file named brown-leather-lace-up-boot.jpg carries information the moment it is opened. A file named IMG_4471.jpg carries none.

It is a supporting signal, not the main one. Alt text does the heavy lifting for image search, as covered in the article on alt text. The filename has one advantage alt text does not: it requires no writing. Where a descriptive sentence has to be thought through, a filename is a few words joined by hyphens.

What Shopify does not do

Alt text is one click away inside the product page. The filename is not: Shopify offers no button to rename a media file once it has been uploaded. The only way to change a name is to re-upload the image under a new one, which gives it a new address on the CDN.

That new address has a consequence people forget. When you change a product handle, that is, its address, Shopify offers to create a redirect so your external links keep working. There is no equivalent for a renamed image: the old address simply stops answering. If that image was indexed in Google Images, pinned on Pinterest or linked from another site, the link breaks the moment you rename it.

What is worth renaming

Not every image sits on the same side of that trade-off. A generic lifestyle shot, unlikely to be shared or indexed on its own, does not justify a broken link for a marginal gain. The main image of a product that sells well does deserve a descriptive name: it is the one a buyer saves, pins, or finds again through an image search.

A good name describes what is visible, in the same spirit as good alt text: the type of product, the material or colour, a variant where it applies. brown-leather-lace-up-boot.jpg rather than IMG_4471.jpg. No stacked keywords, no brand name repeated for nothing. The rules are the ones that govern alt text, because the same reader reads both.

PixelUnik renames a file from its product page, one image at a time, from the Starter plan up. Renaming a whole catalogue in one batch is reserved for the Growth plan, and each renamed image costs one credit, like any other operation. Either way the operation leaves the file weight alone beyond what is necessary: it re-encodes at near lossless quality and never goes below 2048 px, the threshold from the first article in this series. The goal is the name, not compression.

Check your own store

Open a product page, click an image in its gallery, and read the filename shown under the preview. If you find a string of digits or a camera prefix there, that image does nothing to help you get found through image search. Start with your best sellers: they have the most to gain from a name that actually says what they show.