File URL vs Post URL

When you insert an image, WordPress gives you three choices as to how you want to link to that image.

Image Link in WordPress Media Manager

Click to view a larger version of this screen shot

Your choice affects how visitors can view the image and perhaps interact with it:

  • None – the image just sits on the page
  • File URL – the image links to a full-size version of the image. When a viewer clicks on the image in your post, they will be shown the image you originally uploaded, in its full size.
  • Post URL – the image links to an attachment page where the image, in a sense, becomes a blog post of its own. More description about the image is available, and visitors can comment.

Some Things to Consider

File URL

  • There is little benefit in uploading an image that is bigger than your viewers’ browser screen, unless it is important for them to see minute detail in the image. If the image is bigger than the viewer’s monitor resolution, they will have to scroll around to see the whole thing. It will also take longer for it load, and will take more bandwidth as well. For these reasons it is better to resize your images to a size that can easily be viewed on most monitors before you upload them.
  • This is an excellent choice for thumbnails, giving you the best of both worlds: a small initial file upload coupled with the ability to see a much larger image if the viewer wishes to do so.
  • Click on the thumbnail images in Gallery of Thumbnails Linking to Larger Images to see what happens when an image is linked to the file URL.

Post URL

  • This is a great way to include more information about an image than you would want to have in a caption. A large group portrait with four rows of people in it, a bouquet with a dozen kinds of flowers, or a fashion shot where you want to list the source of all the accessories, plus credit the stylists are just some of the situations where a detailed description “off screen” might be desirable.
  • Whatever information you put in the Description field of the image attachment will not be available to viewers unless they click on the image. Thus, you may want to include “Click on the image for more information” in your caption, to make them aware that there is more behind the curtain.
  • Click on the individual pictures in Individual Images with Descriptions to see how the image attachment is displayed to viewers. To a certain extent this is dependent on the design of the theme.