Image SEO

How to optimize your images for search engines:

1. File Name:

  • Do not use the generic name (e.g. DCMIMAGE10.jpg) as assigned by your camera or phone
  • Use descriptive, keyword-rich file names, and separate the words in your filename with a dash (hyphen), and not an underscore (the underscore isn’t a recognized word separator)
  • Avoid writing extremely lengthy filenames
  • Avoid keyword stuffing!


  • Not good:
    • DSC_9807.jpg This tells Google nothing at all!
    • blackcat.jpg  Blackcat is not a word
    • a-black-cat-under-a-red-car.jpg No need to include stop words in your filename (a, the, it, to, etc.). Keep it short and simple
    • black_cat_under_red_car.jpg The underscore isn’t a recognized word separator. To Google, this just reads as blackcatunderredcar.jpg! Which is not a word
    • black-cat.jpg The Internet has probably millions of pictures of black cats!
  • Best:
    • black-cat-under-red-car.jpg Descriptive, and with the correct separators and no stop words

2. Alt Text:

  • “In situations where the image is not available to the reader, perhaps because they have turned off images in their web browser or are using a screen reader due to a visual impairment, the alternative text ensures that no information or functionality is lost.”  Wikipedia
  • Provides enhanced accessibility on your site for those who are unable to see your images, their computer will read the alt text to them, letting them know what’s there
  • Be sure to add alt texts. Make sure the alt text includes your SEO keyword and relates to / describes the image
  • Avoid writing excessively long alt text that would be considered spammy
  • Avoid keyword stuffing!


  • Not good:
    • <img src=”puppy.jpg” alt=””/>
  • Better:
    • <img src=”puppy.jpg” alt=”puppy”/>
  • Best:
    • <img src=”puppy.jpg” alt=”Dalmatian puppy playing fetch”>
  • Avoid keyword stuffing:
    • <img src=”puppy.jpg” alt=”puppy dog baby dog pup pups puppies doggies pups litter puppies dog retriever labrador wolfhound setter pointer puppy jack russell terrier puppies dog food cheap dogfood puppy food”/>
    • Keyword Stuffing results in a negative user experience, and may cause your site to be perceived as spam. Instead, focus on creating useful, information-rich content that uses keywords appropriately and in context.

3. Title:

  • The title tag  is for human readers (not for search engine crawlers!)
  • It’s what’s revealed when you hover over the image without clicking
  • It does improve user experience to have a proper title set
  • Offers a good way to provide non-essential information, for example the mood of the image, or what it means in context (i.e. nice to have info), or can be written as a call to action to prompt a reader to act
  • When you upload an image to WordPress, you can set a title and an alt attribute. By default, it uses the image filename in the title attribute, which, if you don’t enter an alt attribute, it copies to the alt attribute. While this is better than writing nothing, it’s pretty poor practice. You really need to take the time to craft proper attributes for every image you add on your website
  • Avoid keyword stuffing!


  • Not good (if you don’t enter anything, WordPress will copy the filename here – avoid!)
    • chocolate-cake
  • Good:
    • Chocolate Layer Cake
    • Chocolate Cake for Sam’s birthday
    • Chocolate cake recipe

4. Caption: 

  • The text that accompanies the image (displayed underneath your image)
  • People use that text in scanning an article
  • Captions under images are read on average 300% more than the body copy itself, so not using them, or not using them correctly, means missing out on an opportunity to engage a huge number of potential readers
  • Adding a caption to your image can have the same benefit as adding alt text. It tells Google and other search engines what your image is about. However, in some places on your website, captions probably don’t make sense and might look funny, so don’t overdo these. For instance, having a caption underneath your hero image (or main image) in your blog post would detract from your design.
  • Think about the visitor first, don’t add a caption just for image SEO
  • Avoid keyword stuffing!
Image attributes
Image SEO example