9 Tips to Optimize Images for Search Engines
The right image can provide invaluable context to visitors, and break up what would otherwise be a wall of text. But search engines can’t ‘see’ images the way that humans do, which is part of the reason why it is important that you specifically optimize your images for search engines.
Don’t worry if that sounds complicated, because it is actually rather easy once you know what you need to do.
9 Tips to Optimize Images for Search Engines
1. Name Image Files Descriptively to Provide Context
Imagine for a minute that you are a search engine bot and you run into an image named Image0001.jpg. The file name doesn’t really tell you much apart from the fact that it is presumably the first image in a series.
If the image used a more descriptive file name such as dark-colored-shirt-XL.jpg on the other hand — more information could be gleaned from it. A search engine bot would be able to surmise that the image is of a shirt in a dark color that has an XL size.
That pretty much sums up why naming image files descriptively is always a good idea. The context that it provides is invaluable, and will definitely help search engines understand the image.
When you name your image files descriptively there are a few rules to follow:
- Use hyphens (-) to indicate spaces, and not underscores (_).
- Use plain language that is relevant to the image.
- Do not make it too long.
- Avoid keyword stuffing that does not add context.
2. Add ALT Attributes to Images
Every image that you publish on your website should have an alt attribute added to it. That alt attribute will specify an alternative text that will be displayed if the image cannot be loaded — and more importantly, will provide invaluable additional information to search engines.
The only images that should not have alt attributes are images that exist purely for decorative purposes — and do not contribute any other value or information.
As you can imagine, it is best for the alt attributes to be descriptive so that they can act as an alternative to the image itself — just like the file name. However alt text can be longer than the file name, allowing you to describe the image’s contents more effectively.
Only add keywords to alt text if they are natural and fit the image. Keyword stuffing of alt text is never a good idea, and should be avoided.
3. Place Captions Below Images
Another useful way to give search engines (and visitors) more information about your images is by placing a caption below them.
Essentially a caption is just a small line or paragraph of text that is normally placed directly below the image in its own box that describes the image and what it is about. That context can be invaluable to visitors, and search engines will benefit in a similar fashion.
As with alt-text, captions should not be added to decorative images. In fact, they should only be added to images where the additional context would be required and appropriate.
4. Use the Right Image Format
The format that you choose to save images in is important when you are going to be publishing them on a website. In particular, there are a few common formats that you should use for almost all of your images:
- JPEG or WebP should be used for the majority of larger images and photos and will provide decent quality at small file sizes. Although WebP has better compression than JPEG, it is less widely supported.
- PNG should only be used for images with transparent backgrounds — and even then only if the transparent background is really necessary.
- SVG is perfect for logos and icons and will allow you to scale both as required by using CSS itself.
Although at one stage GIF was a popular online image format, it is far less popular nowadays — mostly because of how inefficient it is. It is better to use video formats as opposed to animated GIFs or use PNG for transparent backgrounds.
