you can use inspect element to see product image source and download the images .
the sizes of image are more than 400 kb.
I want to reduce the size of the image.
please help me to find solution.
Use the Resize function in magento like;
$_imageUrl = $this->helper('catalog/image')->init($_product, 'small_image') ->resize($width, $height);
<img src="<?php echo $_imageUrl; ?>" />
or use the bellow extension allows you to optimize all the images in your site, also you can Schedule your Optimization.
@jason's answer is entirely correct, you probably just need to add the 'resize' part to your template where it pulls through the hi-res 'thumbnail'.
Obviously there is more than one way to do anything. You can just set the web server to only serve images of a certain size (or smaller), with it dynamically resizing and optimising anything it finds.
Add Google's Pagespeed Module to your server and configure it to just work on your images for now. The instructions for that are here:
This entry is particularly worth the read for where you are:
The advantage of the Pagespeed way is that you don't have to manually worry about uploading the correct size images or making sure your templates are behaving. You can just let Pagespeed sort it out and you can then focus on developing other aspects of your site.
Why not run your image folder thru Photoshop and resize/optimize the images. Drop them back in your media folder and be done with it? Batch process your images to a smaller/progressive format and use a standard image size like 900x900 or whatever for your future images. Irfranview is a free alternative that can batch process. Your images are 400kb because they are huge and not optimized.
Instead of resizing each image individually, you will get more benefit from making sure you are serving the right image. Eg when to use Spriting, PNG, JPG and others.
It is possible to do this manually or to automate the browser optimization and quality globally using a image processing platform.
If you automatically serve WEBP images instead of JpG to chrome users and JPG XR images to Internet explorer- you gain an immediate benefit of up to 50%-80% reduction in size. Adding in a CDN will also give a lot of advantages and make the images faster.
If you share the url - then I am happy to give specific advise.
Otherwise here is a case study - that might be useful: http://www.magecloud.net/blog/a-case-study-speed-up-magento-pages-by-over-50-with-automatic-image-processing/