There’s more to image SEO than writing a few alt tags—a lot more. Some may even argue that with Google’s recent advances in machine learning, alt tags no longer matter. For example, here’s what happens when you upload a photo of a cat into Google’s Cloud Vision API—their machine-learning image identification tool: That example comes straight from Google’s official guidelines. It’s used to show what a well-written alt tag looks like. Here’s their general advice for writing these: Google uses alt text along with computer vision algorithms and the contents of the page to understand the subject matter of the image.
When choosing alt text
Focus on creating useful, information-rich content that uses keywords appropriately and is in context of the content of the page. Avoid filling alt attributes with company data keywords (keyword stuffing) as it results in. A negative user experience and may cause your site to be seen as spam. Matt Cutts gives some equally good advice for alt text in this old, yet still relevant video: Oh, and don’t forget about captions. Those are important too. Here’s what Google says: Google extracts information about the subject matter of the image from the content of the page, including captions and image titles. Wherever possible, make sure images are placed near relevant text and on pages that are relevant to the image subject matter.
Look at that last
Image again to see an example of an image caption. It’s the small text below that describes what it shows. I recommending using these wherever possible. 3. Choose the Mobile Numbers best file type Image SEO Most images on. The web are one of three file types: JPEG, PNG, and GIF. Each of them uses a different compression method. That means file sizes between the three file types can vary dramatically. That’s important. Here’s why: Images are often the largest contributor to overall page size, which can make pages slow and expensive to load. Page load time is crucial for SEO. Google has confirmed that it’s a ranking factor on both desktop and mobile. Your task is to choose the most appropriate file type for each image.
