How Google Classifies Your Images
First, let’s talk about how Google classifies your images. Google is interested in helping people find the images they are looking for. The first thing Google does is try to identify all the duplicate images and filter them to show the best one. This means that, like content, unique images will win out against images that have a lot of replication. Next, Google results can be filtered, by size, type, and color. The types include news, faces, clip art, line drawings and photos. So these categorizations of your image are important, because people use these filters to narrow their image search, and this gives you an opportunity to position yourself for very specific image search results.
Using Alt Tags
Alt tags are vital for your images. Alt tags are the alternate text that is displayed when the image is not available, and search engines use this text to identify what the image is. For example, the alt tag for a banana would be, (you guessed it) banana. In most cases, the alt tag really is that straight forward.
Using a Title Tag for your Images
While not as important as the alt tag, the title tag is also important. The title tag is the title of the picture, and should describe it accurately. Users will see this title when their mouse hovers over the picture.
Image Captions describe the picture in detail. The more details you provide, the easier it’s going to be for the search engines to rank your picture.
Which image name tells you more about the image: “tf7g9.jpg” or “yellow_banana.jpg?” Naming your images to reflect the substance of the image is important. This image name also shows up in the URL where the picture is located. So your URL would look like this: “http://yourdomain.com/yellow_banana.jpg” This URL, in addition to the alt tag, title tag and caption, helps search engines understand what the picture contained on the page is.
Images Optimization Best Practices
These are some best practices for image optimization according to Google. In general, try to provide the best user experience on the page as a whole. This includes:
- Thinking about what the user is looking for and trying to provide that with your images
- Offering high quality images
- Providing lots of descriptive text
- A good image title
- A strong caption
- Related pictures
- Ability to rate pictures
- Immersing the user into an image centered experience