How to stop the browser from caching images

I came across this issue when building an “image manager”. The user would be prompted to upload an image, I would save it and change it’s name to a meaningful code. Problem is that when the page refreshed, the old image still showed. This was due to browser caching.

The browser uses caching so that you don’t have to download the same image multiple times. It recognizes an image by the url, so in order to stop caching we need to change the url so that the browser recognizes it as a new image.

C# Code:

// Add a meaningless but UNIQUE query string parameter to the url to stop browser caching the image
imgThumb.ImageUrl = String.Format("{0}?{1}",
imageUrl,
DateTime.Now.ToFileTimeUtc());

Please note that the following example is using C# server-side code to manipulate an ASP.NET <asp:Image> control . You could implement the same principle on a <img> tag’s “src” attribute using JavaScript