Images
Images are used on websites to provide more engaging experiences for users, while also presenting more information about a topic. While positive for user experience, images can cause issues for a website’s SEO and performance. Our key takeaways from Google’s ongoing SEO Office Hours sessions cover more insights into the impact of unoptimized images, as well as best practice recommendations from Google.
For more on website content best practices for SEO, read our Guide to Optimizing Website Content for Search — or explore our Website Intelligence Academy resources on SEO & Content.
Google Doesn’t See Embedded Images as Links to Another Site
Google don’t treat embedded images in the same way as a link to another website.
Image Sitemaps Associate Images With Pages But Don’t Provide Context For Images
Image sitemaps are useful for Google as they show what images are associated with what landing pages, but they don’t provide context about the images themselves like alt text and image titles do.
Image Tags Without A Href Elements Aren’t Treated as Links
For an image to be considered as a link by Google, it needs to have an ‘a’ tag and href element. Using an img tag to point to an image on another site, for example, is not seen as a link.
Google Doesn’t Support Canonical Tags for Images
Canonical tags don’t work for images, so you can’t fold together different sizes of an image to make sure only the best size is indexed, for example. Google is looking into how best to use srcset for image search, however.
Redirect Old URLs When Migrating Images to a New CDN
When migrating images to a new CDN, make sure to redirect the old image URLs to the new ones as well as updating the embedded links in the webpage. Images aren’t crawled as frequently as webpages so you need to make sure all signals are aligned so Google can move them over as quickly as possible. Consider setting up a subdomain and transferring the images, so the URL doesn’t change except from the hosting.
Use the NoScript Tag or Markup For Lazy-loading Images
Add a NoScript tag to lazy-loading images or mark them up with structured data to help Googlebot process them.
Data-alt Attributes Have No Impact on Image Search or Regular Search
With regard to images, data-alt attributes are used more for lazy-loading and giving other information for images from scripts, but this isn’t used for indexing in any way.
Noindexing Images Will Cause Omissions From Image Search & Video Search
Noindexed images won’t appear in Google image search and if a site hosts its own videos the thumbnail image won’t be indexed, meaning that the video won’t be indexed either.
Images in a Body of Text Doesn’t Improve its Quality
Having imagery within a body of text doesn’t provide any SEO signals that will tell Google that it is better than a piece of content without imagery.
A Featured Snippet Can Source its Text & Image from Different Sites
Images in featured snippets are sometimes taken from a different website to the one where the text snippet was taken from.