Search engine optimization, typically called SEO, can make or break your site. SEO is the process of increasing your website’s visibility to search engines. It’s a popular topic but there’s one SEO-related issue that tends to be overlooked: image optimization. How much traffic are you losing due to poor image SEO?
Yes, it’s true. Image searches can drive a lot of traffic to your website if you know what you’re doing. The trick is to understand how search engines work and format your images accordingly. Here are a few fundamental tips that will get you started.
Image SEO Tip #1: Alt Text
“Make sure you set your image alt tags” is one of the most common pieces of advice when it comes to image SEO and for good reason. Technically, IMG is the tag, and ALT is the attribute. What is the attribute? It’s a short text description of your image and it’s used to give context to search engines regarding the said image.
Have you ever wondered how Google knows how to bring up the right pictures when you run an image search for “dandelion”? There are a lot of factors but alt text is one of the most important. Without it, Google wouldn’t know the difference between dandelions and tulips.
Fortunately, alt attributes are easy to implement. Just insert a bit of HTML into your <img> tags:
But keep in mind that alt text won’t help you much if you don’t use them correctly. Here are some tips for making the most of them.
- Use keywords. General SEO tactics apply to alt texts too, which means keywords are still extremely important. Remember to be descriptive and contextual!
- Short and sweet. Keep your alt attribute length below 125 characters and don’t stuff in too many keywords. Bad case scenario — some search engines may skip alt texts that are too long. Worst case scenario — some search engines may ignore your images entirely.
- Not always needed. Alt attributes should only be used for images that you want indexed by search engines. Other images, like website backgrounds and theme elements, can be ignored.
Image SEO Tip #2: File Names
Like alt texts, file names are important because they provide further description of your image for search engines. If your image file name is nondescript gibberish, Google won’t know what it’s supposed to represent.
For example, your smartphone camera might produce an image with a file name like IMG_20140318_152680.jpg. Is that a picture of an apple? A car? The Eiffel Tower? It would be much more helpful to call it red-panda-eating-carrots.jpg. Suddenly, the image has context.
Fortunately, file names are easy to change. It requires very little effort for you to rename your images and the results are more than worth it. Here are some guidelines to keep in mind:
- Use keywords. No surprise here. The reasoning is two-fold: keywords help Google to contextualize your image (just like alt tags), but image file names are also used in URLs.
- Hyphens are best. SEO experts consider it best practice to separate file name keywords using hyphens (-). Rejected alternatives include plus signs (+), underscores (_), and whitespace ( ).
- Short and unique. Include no more than 4 keywords in the file name, though I personally prefer to cap out at 3. Be descriptive and unique without being ambiguous or confusing.
Image SEO Tip #3: File Size
A few years ago, Google announced that page loading speeds would become a factor in search rankings. In hindsight, it makes a lot of sense. Between two sites of equal value, the faster one will always be preferred. The takeaway is that faster-loading images will tend to rank higher in search results.
The best way to improve image speeds is to reduce file size and the easiest way to reduce file size is to use an image format that’s optimized for the web:
- PNG. For the most part, PNG is the preferred image format for Internet use. It supports transparency, it has lossless compression, and its file sizes are small. Plus, there are PNG compression tools for even further file size savings.
- JPG. This is the standard format for photographs and images that have huge color palettes (millions of colors in a single image).
- GIF. Useful for animations and static images with fewer than 256 colors.
Don’t resize dynamically. If you upload a 400×300 image and display it at 800×600, it will look ugly. On the other hand, if you upload an 800×600 image and display it at 400×300, you’re wasting a lot of bandwidth. Always size the image to the correct resolution BEFORE you upload it.
If you want to know more about image compression, read the page where Google Developers head to — PageSpeed Insights (Optimize Images)
Image SEO Tip #4: Page Context
What if you run a website that’s nothing but photos? Let’s say you have a portfolio of photographs, web designs, game screenshots, etc. How will search engines know what those photos are about? More importantly, how can you make sure that your portfolio ranks well?
The answer lies in page context.
Computer scientists haven’t yet engineered a way to look at an arbitrary photo and determine what it is without contextual hints, which means you need to provide said context. Do this by surrounding your images with relevant text, keywords, etc.
There are many ways to influence the context around an image. Alt text, as explained in Tip #1, is one example. Image titles and captions are another example. Paragraph text can be useful, website titles can be useful, and even comments can be useful. Search engines will utilize as much information as they can find on the page.
For more information, check out this video on gaining PageRank with images.
There are a handful of other image SEO tips out there, but they’re quite nuanced and don’t provide as much bang-for-the-buck as the four tips outlined above. In fact, as long as you employ proper use of alt texts, file names, and file sizes, you should start to see an increase in the amount of search traffic brought in by your images.
Know any other image SEO tips that can prove helpful? Please share them with us in the comments!
Image Credit: Forest Light via Flickr