Image File Names for SEO: How to Name Images Right

This guide shows you how to write image file names for SEO the way Google recommends, gives you a naming formula you can reuse for blogs and online shops, and explains what to do with images you have already uploaded. Renaming images is one of the cheapest on-page fixes I make for clients, so it is worth getting right from the start.

Do image file names matter for SEO?

Yes, image file names matter for SEO, but as a small supporting signal rather than a major ranking factor. Google uses the filename as one clue about what an image shows, alongside alt text, captions and the surrounding page text.

Google’s image SEO best practices say that the filename can give Google very light clues about the subject matter of the image, and recommend filenames that are short but descriptive. Google’s own example is that my-new-black-kitten.jpg is better than IMG00023.JPG. The same page advises avoiding generic filenames like image1.jpg, pic.gif or 1.jpg when possible.

In practice, the filename matters most for Google Images traffic and for product photos, where many images look similar and text signals help Google tell them apart. On a blog post, the filename alone will not move rankings, but it costs nothing to do properly and it adds to the overall picture.

The filename also becomes part of the image URL. Anyone who sees that URL, in a shared link, an image search result or a browser tab, sees a clue about what the image contains.

Should image file names use hyphens or underscores?

Image file names should use hyphens between words, not underscores or spaces. The filename is part of a URL, and Google’s URL guidance recommends hyphens to separate words.

Google’s URL structure best practices say it recommends hyphens instead of underscores and, for historical reasons, does not recommend underscores. Spaces are even worse: they get encoded as %20, producing file URLs like red%20leather%20sofa.jpg that look messy and are easy to break.

The other rules I follow for every filename:

• Lowercase only. URLs are case sensitive, so mixing cases creates confusing duplicates.
• No special characters. Avoid apostrophes, ampersands, commas and accented letters unless your audience’s language needs them.
• Translate for localized sites. Google advises translating filenames when you localize images, keeping URL encoding rules in mind.
• Keep the right extension. Google Images supports BMP, GIF, JPEG, PNG, WebP, SVG and AVIF, and the extension should match the real format.
• No keyword stuffing. One clear description beats a list of keywords.

What is a good naming formula for images?

A good naming formula is subject plus key detail plus context, written in plain words in the order a person would describe the image. This table shows the formula applied to common image types.

For shops with hundreds of products, build the filename from data you already have: product name, colour, size or angle. That keeps names consistent and makes bulk renaming possible with a script or a plugin.

Should I rename images before uploading to WordPress?

Yes, you should rename images before uploading to WordPress, because the filename you upload becomes part of the permanent image URL in your media library. Renaming later is possible but more work.

When you upload a file to WordPress, it keeps your filename in the file path, usually inside a dated folder such as /wp-content/uploads/2026/03/. WordPress also creates resized copies with the dimensions added to the name. Changing the visible title in the media library does not change the file URL.

My upload routine for client sites:

1. Resize and compress first. Export at the largest size the layout needs, then compress. Large files slow pages down far more than a bad filename hurts.
2. Rename on your computer using the formula above.
3. Upload and check the file URL in the media library.
4. Write alt text in the media details or block settings. The filename does not replace alt text.
5. Place the image near relevant text, which Google also recommends, so the page supports what the image shows.

For images already uploaded with bad names, rename only the important ones, such as product photos and images that already get Google Images traffic. Renaming changes the URL, so update every page that uses the image and redirect the old file URL to the new one. Google also advises referencing an image consistently with the same URL so it can cache and reuse it, which is another reason to choose good names once and keep them. If you are building a new site, set naming rules from day one; it is part of how I hand over every WordPress website design project.

What image file name mistakes should I avoid?

The biggest mistakes are uploading camera or screenshot names unchanged, stuffing keywords into filenames, and renaming large numbers of old images without a plan. Each of these either wastes the opportunity or creates new problems.

These are the mistakes I find most often when I audit image libraries:

• Camera defaults everywhere. Names like IMG_4471.JPG or DSC00023.jpg on every product. The fix is a naming step in your upload process, not a one time clean up.
• Same name, different image. Ten files called banner.jpg in different folders. When names are unique and descriptive, both people and systems can tell images apart.
• Brand name on every file. Adding the company name to every filename adds length without describing the image. Use it only when the brand is what the image shows, such as a logo or packaging.
• Keyword lists. Names like plumber-london-cheap-plumber-emergency-plumber.jpg look like spam and describe nothing.
• Renaming without updating pages. Changing file names on the server without updating the pages that use them leaves broken images.
• Ignoring file size. A perfectly named 4 MB photo still slows the page. Compress first, then name.

Most of these come from rushed uploads, so the long term fix is a written rule that everyone who adds images follows.

How should I name images for a real product page?

Images are one part of a wider media strategy that includes video, captions and structured data; my content and media SEO service covers all of it. For a quick self check, image filenames and alt text are both in my free SEO audit checklist, and I review them on every on-page SEO project.

Frequently asked questions