Image with parameter - HTML

Question

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Answer 1

If this image is dynamic in some way, then the server that's hosting this image must be generating the image from PHP code.

Take a look at the GD library, which lets you use PHP to generate images based on nothing or other images. The parameter must be passed to include that value inside the image (for example, an image that includes the text "123" or calculates using it somehow, for example a user ID).

Then an .htaccess on the server rewrites the extension of .png to .php (or maybe another one) to make it look like a genuine image to some libraries and crawlers, or scripts etc.

Another option, is that this is a simple image and that value is being ignored, or is just random to make sure the image isn't cached.