Downsizing and optimising image size for pages and posts

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    Firstly, is it better to downsize images outside of WordPress before adding them to the Media Library, or downsizing them using the Resize tool in the image editing page?
    Secondly, in your guide to image size, you say

    if we detect a Retina display we serve the image at double the size so it displays with maximum sharpness, but that only works if the image that appears in your media library is larger than the size that appears on your site.

    Does this mean that I should upload the image to the Media Library at the original size (by way of example, 2000 pixels wide) then downsize to 740 pixels wide (the standard width of the single column version of the Twenty-Seventeen theme). Then, when a Retina screen is detected this will automatically upsize to 1480 pixels wide (or to the full size of the image in the Media Library, if that is smaller than 1480 pixels wide). Many thanks, Rob

    The blog I need help with is


    Hi again. I just uploaded an image 1480×1059 pixels in size (downsized using the Scale Image feature). However, when I added it to a page, the size appears to be 525×376 pixels (see below). Do you know why this is? Many thanks, Rob

    <img src="" alt="Earthrise from the Moon, photographed by Apollo 8 crewmember Bill Anders" width="525" height="376" class="aligncenter size-large wp-image-71446" />


    Update – I have also found that the image does not stretch right across from the page left margin to the right margin, it is narrrower than the 740pixels width, even though it is present in the Media library at 1480×1059 pixels. Do you know how I can get images to stretch right across the width of the column? Many thanks.


    I had a reply from a chat session on the issue of whether to downsize an image outside of WordPress before uploading. Their answer was: “For personal preference (I can’t say if it is better or not), I optimize my images before uploading them. But when I do, I upload them as large as a can so that Retina displays are still clear.”

    I also have a solution to the issue of images not stretching across the full width of the column in TwentySeventeen theme, when viewed on a computer screen. This solution was provided by staff member Achyuth Ajoy. The solution is as follows:

    I have found a solution to fix the image problem on blog posts. To set your images to full-with follow the steps below.
    • Open the URL:
    • Set Max Width of Large size section to 1000.
    • Save the changes.
    Here is a screenshot:
    Image link:
    The problem was that since the large image size was set to 640, the image won’t take up the full-width on desktop browsers.
    The above steps will solve that problem.

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