Images play a big role in content marketing and SEO.
They help with content readability, user engagement, average page on time, and even conversions. Similarly, optimised images also help Google understand what the page is about and even bring additional organic traffic from Google Images search results.
We all know that image alt text is a strong signal.
But what about the image file name?
In a recent Search Off the Record podcast, Google’s John Mueller and Lizzi Sassman discuss the importance of image filenames, share best practices, and warn users of a seemingly innocuous mistake that could cast plenty.
Google’s image guidelines documentation
But before we jump into their conversation, let’s briefly see what the Google image guidelines documentation says about image file names.
“The filename can give Google clues about the subject matter of the image. For example, my-new-black-kitten.jpg is better than IMG00023.JPG. If you localize your images, make sure you translate the filenames, too.”
The SEO importance of image file names
At the start of the conversation, Lizzi and John reaffirmed Google’s image guidelines documentation’s stance and the importance of descriptive image file names.
“We do recommend doing something with the filenames in our image guidelines. So having descriptive filenames is good. But I don’t think you would see a significant change if you already do the other things around images, like the alt texts, [and] the text surrounding the image.
Those are really, really strong signals.
And the filename itself is often… it’s kind of from a technical point of view. This is what we called it, but it doesn’t provide any real unique information, usually.
Of course, if you don’t do the alt text, or if you don’t have good surrounding text, then, of course, the filename might be the only place where you mention what this image is about.
But if you do the rest, then usually the filenames are okay.”
Optimising image file names, changes, and Google crawling
The above information leads to an important question: if descriptive image file names help, and if your website doesn’t have optimised images, should you change them?
Before jumping into the potential benefits of undertaking an optimisation campaign, it’s a good idea to hear John’s thoughts on a technical issue — how Google crawls images.
According to him, when you change an image file name, it’s a very slow process. Unlike content, Google doesn’t crawl images as often because there are rarely any changes there.
“And the other thing with filenames, especially for images, is when we crawl images, we tend not to crawl them as often, because usually, they don’t change a lot.
So that means if you change all of the filenames across the website, then it’s going to take a lot of time for Google’s systems to see, “Oh, well, this is a new image, and we have to kind of look at it at some point.”
And to understand kind of that connection between the old image and the new one, that’s something that’s just going to take a very long time.
So if you changed all of them at once, my guess is… I don’t know, over a period of a couple of months at least, it’ll be kind of annoying in Image Search in that we kind of drop the old ones first because they’re no longer mentioned on the page and pick up the new ones in a really slow way.
So that’s something where I would try to only do that if it’s really, really critical.”
And updating image file names is rarely critical.
But … will changing your image file names help with SEO at all?
John Mueller doesn’t think so — especially considering the effort and probability of human error.
“I don’t think that would make it better. That probably would have minimal effect, maybe no visible effect at all,” says John.
Not to mention the chances of making a mistake (e.g., missed redirects or broken links) that could cost you search traffic. In addition, it could also have a negative impact on your website’s health and technical SEO foundation.
Summary and takeaways
So here are some notable takeaways from this very insightful discussion.
- Descriptive file names for images help because they help Google understand what an image is about.
- However, they are not as strong a signal as alt text and the text that surrounds the image on a web page.
- If you already have images with improper file names on the website, most of the time, it won’t be worth the effort to update all the file names. That’s because Google doesn’t crawl images as frequently as it crawls content. And changing the images may result in images going uncrawled and not indexed for several weeks.
- Local businesses, however, should try to upload optimised images from the start. This includes uploading relevant images with contextually meaningful surrounding text, small file sizes for maximum loading speed, and keyword-rich and descriptive alt text and image file names.
We hope you found this article useful. Stay tuned for more SEO news, tips, and strategies.
