Image title vs alt text vs file name: What’s the difference for SEO?
Image SEO is an important part of optimizing your website for search. Whether your goal is to have your image appear as a rich result, boost the page your image is on or even just rank on Google Images, you will likely have to deal with image SEO. When you are optimizing your images, you need to pay attention to all the text around your image, including the alt text, file names and image titles. In this guide, we show you how.
What is alt text?
Alternative text — also known as alt tag — is data specifically designed to make an image more accessible. It is the text displayed in place of an image if the image cannot load or if the user is browsing via a screen reader. Allowing screen reader users to understand the context behind an image makes the internet more accessible for the visually impaired. This is equally important for search engine optimization (SEO) because Google prioritizes websites that provide a good user experience for all visitors.
Most content management systems allow you to add alt text as you upload an image. However, when you don’t add any alt text, the image just appears empty if it cannot load.
What is an image/picture title?
An image title is essentially the name of an image. It’s the text that appears when a user hovers their mouse right above the image. It is distinct from an image description, which normally appears as a more textually heavy caption underneath the image. Image titles also appear in the HTML of a webpage and you can see them by right-clicking on images and hitting “inspect.”
The picture title is not displayed if the image fails to load, and screen readers generally won’t pick up on it, so its purpose is purely informational. There’s little to no impact on the accessibility of an image.
Image titles can be useful for user experience, giving readers more information about an image if they wish. They are a great opportunity to add optional context to an image without crowding your webpage.
What is an image file name?
An image file name is exactly what it sounds like: the unique identifier that both people and computers use to differentiate one image from another. Anytime you save or edit an image, you can give it a file name that will be used to identify the image offline on your computer system. Browsers also read and store image file names — you can view them by inspecting the image.
Once again, file names have no impact on accessibility since they are not displayed anywhere on the webpage unless a user decides to download the image.
How do the image titles, alt text and file names impact SEO?
All three have varying impacts on SEO, with alt text and file names being crucial for image SEO and titles being significantly less relevant. Alt text and file names help Google’s web crawler understand the context behind an image. Since the bot cannot just look at an image and understand what it means, it looks at the metadata (filenames and alt text) to understand and rank an image.
In their image SEO best practices, Google does not specifically mention image titles the way it does with alt text and file names. Google, however, mentions that all text around an image is used as context for said image. Google’s crawlers use this context to determine the relevance of an image to a certain keyword, which directly influences its ranking.
Context does not just comes not only from alt text, file names and image titles but also from the text near the image, including headings and captions. So you should optimize all the text around an image, particularly if the image is important.
How to optimize your image titles, alt text and file names
When optimizing your images for SEO, try to keep them as user-friendly as possible. Google will always prioritize user experience since its goal is to provide searchers with the most useful and relevant content. Here are our top tips:
Optimizing alt text for SEO
When writing your image alt texts, you must do more than add a keyword or two. Your alt text needs to describe the image and the context that it adds to the page.
- Include a keyword but do not stuff. In other words, add keywords wherever they can be justified.
- Do not start your alt text with something like “this is an image of” or “this image.” Instead, get straight to the alt text.
- Only add alt text to images that add value to a page. Decorative images do not need alt text.
- If your image contains text, you should add it to the alt text, too.
- Keep your alt text short — normally within 125 characters, unless the image is central to the page.
Optimizing image file names for SEO
When it comes to your image file name, you have considerably less room to work with. Google recommends your file names be descriptive but short, so avoid generic file names such as “Image01.” Follow these best practices when naming your image files:
- Use identifiable file names. The name should help users understand what the image is without them having to open it.
- Keep the name under six words.
- Use hyphens to separate words instead of spaces.
- Use a keyword wherever applicable. Do not stuff your file names.
Optimizing image titles for SEO
Your image title is the least important part of image optimization. It serves very little purpose for user experience because it only appears when a mouse hovers over the image and screen readers won’t pick it up. However, if your title tag contains important information, you should also make that information available elsewhere on the page.
This doesn’t mean it will hurt you to optimize your image title — just know that image titles alone are not a very strong or important ranking factor. Similarly to alt text, when optimizing your image title, try to be descriptive and use a keyword wherever possible, but avoid keyword stuffing.
🏷️And how about URL structure? Does it impact SEO? Read our guide on URL best practices to find out.
Need help with SEO?
If you want to understand all the many steps behind building and implementing a strong SEO strategy to generate leads for your business, get in touch with our team of SEO consultants and we will be happy to help out.
Frequently Asked Questions
What is the point of image descriptions?
An image description is a text that makes the image more accessible to visually impaired users. Alt text, captions and long in-text descriptions all fall within the umbrella of image descriptions. You should always try to describe your images for visually impaired users (or users with really bad internet), so your website is more accessible. It is good for user experience and SEO.
What kinds of image metadata are used for SEO?
Image alt text, titles and file names are all used in some capacity for SEO, but the most important metadata is the alt text and file name.
Should you optimize your image captions for SEO?
Yes, you absolutely should. Google has said that they use all the text around an image to understand its meaning and relevancy for a given keyword. This text includes the caption that normally sits right underneath the image. Try to make the caption descriptive, informative and user-friendly. If you can fit a keyword into your caption without hurting the user experience, then you should add it.
Momin Shahab is an SEO consultant at Productive Shop. He has worked in SEO on an international level for upwards of three years at various companies. He has gained training in content marketing, project management and data analysis. When he's not working or researching SEO, he is reading and collecting books.