Image Filename SEO

Before an image ever lands on my server, I rename it on my local machine. For a client selling hiking gear, I ran a test on 200 product images. I renamed half from their generic 'IMG_1234.jpg' to descriptive names like 'men-brown-leather-hiking-boots-side-view.jpg', and left the other half as-is. Over three months, the renamed images saw a 14% higher click-through rate from Google Image search. That is not a game-changing lift, but it is measurable and cost-free. Some SEOs argue the effect is too small to bother with. I would counter that the effort is negligible – five seconds per file – and the cumulative effect across hundreds of images adds up.

My naming rule is simple: describe what the image shows in 3–5 words, separated by hyphens, all lowercase. If the image supports a page about 'best hiking boots' and the photo shows a pair of boots on a trail, I use 'hiking-boots-on-trail.jpg'. I do not force a keyword if it does not fit. For example, if the image is a beautiful landscape with no product, I name it 'mountain-lake-sunset.jpg' rather than 'scenic-background.jpg' – the former is more specific. There is an edge case for decorative images, like a subtle background pattern: I still use a sensible name like 'light-geometric-pattern.png' instead of 'bg.png' or 'image1.png'.

I also consider the user who might download the file. A filename like 'IMG_2020.jpg' helps no one when they are browsing their downloads folder. Descriptive filenames improve usability, which indirectly helps SEO because users may share or link to the file more easily. This is part of a broader [on-page SEO](/on-page-seo/) approach that considers every signal, not just the obvious ones.

Finally, I batch-rename files using a simple script when I have many images. That saves time and ensures consistency. The decision rule I follow: if someone saw this filename without the image, would they know what it shows? If yes, I upload. If no, I rewrite it.

Here are the pitfalls I have learned to avoid. First, do not keyword-stuff the filename. I once saw a competitor use 'buy-affordable-cheap-discount-hiking-boots-online.jpg'. That looks manufactured and helps no one. Google's guidance is clear: be descriptive first. A filename should answer 'What is this image?' not 'What keywords do I want to rank for?' Second, never use underscores. I used underscores for years because I thought they looked cleaner, but Google treats them as joiners – 'hiking_boots' is read as one word. Hyphens are the correct separator. Third, do not name files after the page URL. If your page URL is '/product/hiking-boots' but the image shows a tent, do not call it 'hiking-boots.jpg'. That misaligns the visual signal and can confuse Google's understanding of relevance.

Fourth, avoid overly long filenames. I used to write 'best-hiking-boots-for-men-under-100-dollars-review.jpg'. Google recommends short but descriptive. Now I aim for 3–5 words that actually describe the image. Fifth, be careful with case sensitivity. Some servers treat 'Product.jpg' and 'product.jpg' as different files, which can cause broken images. Stick to lowercase. Sixth, avoid including dates or version numbers unless essential. 'hero-banner-v2-2024.jpg' is less useful than 'hero-banner-winter-sale.jpg'.

A counter-argument worth noting: some content management systems auto-generate filenames from image titles. If your CMS uses a sensible pattern, that may suffice. But for important images – product photos, hero images, infographics – I prefer manual control. The effort is trivial, and the potential upside is a cleaner media library and a slight edge in image search.

Another watch-out: do not ignore alt text. The filename is a supporting signal, but [alt text](/alt-text/) is a primary on-page element for both accessibility and image ranking. Spend more time on alt text. Finally, do not rename images already indexed if it is a massive effort. Focus on new images going forward. For examples of good alt text, see [alt text examples](/alt-text-examples/).

I made several mistakes with image filenames that I now correct. First, I believed image filenames were a major page ranking factor. They are not. Google's documentation calls them a 'supporting signal' for image search, not a direct influence on page rank. I was spending time optimising filenames for keywords that had nothing to do with the image, hoping to boost the page itself. That was wasted effort. The real value is marginal and confined to image search traffic.

Second, I used underscores for years. I thought they were standard, but they actually join words, making 'hiking_boots' read as a single term. When I finally switched to hyphens, I saw no immediate jump in rankings, but at least I aligned with best practice. I also used long, keyword-dense filenames like 'best-hiking-boots-for-men-under-100-dollars-review.jpg'. I now know Google recommends short but descriptive names. I cut those down to 3–5 words that describe the image content, not the target keywords.

Third, I neglected alt text in favour of filenames. I thought if the filename was perfect, I could skip alt text. That was wrong. Alt text is far more important for accessibility and image ranking. The filename is a minor nudge; alt text is the main signal. I now prioritise writing good alt text for every meaningful image, using techniques from [seo copywriting](/seo-copywriting/).

Fourth, I ignored internal linking of images. I would upload images but never link to them from relevant pages. Now I make sure to use descriptive filenames and then internally link from related content, following [internal links SEO](/internal-links-seo/) best practices.

Finally, I did not consider the user's experience when they download the file. A filename like 'img_2020.jpg' is useless for someone organising their own media library. Now I think about both SEO and usability. I also learned that image SEO is part of a larger picture – see [image seo](/image-seo/) for the full approach.