ShortPixel Adaptive Images - How are the credits counted?
Important: Starting March 1st, a new billing system will be introduced. To learn more about this, see New billing system for ShortPixel CDN.
ShortPixel Adaptive Images (SPAI) processes and serves images on the fly via a fast CDN with a global presence. Unlike ShortPixel Image Optimizer, SPAI does not optimize the physical files on your server:
SPAI only processes your images if they are viewed at least once from your front-end. Until that happens, the image will remain un-processed. Here's more information about how SPAI works: How does ShortPixel Adaptive Images work?
To process an image, a ShortPixel Adaptive Images credit (or API call) is used. Processing an image means smart-cropping (if chosen), resizing, and optimizing it. Once the image is processed, it is stored for 30 days on the ShortPixel servers and it can be served, via CDN, an unlimited number of times during these 30 days. Once 30 days have passed since the image was first processed, it will be dropped from storage and a new credit will have to be used to process it again.
Both one-time and monthly credits can be used to process images.
A simple one-page website with a total of 20 images. The visitors are coming from 3 different viewports requiring 3 different sizes to be automatically generated for each of the 20 images.
20 images * 3 different sizes = 60 credits
A total of 60 credits will be used each month and there is no need to purchase any plan as the monthly free plan of 100 images is enough to cover the monthly used credits.
A small website with 1,000 images distributed in different pages, viewed by visitors from 4 different viewports. This means that up to 4 different sizes will be automatically generated for each image so they can perfectly accommodate the 4 different viewports.
1000 images * 4 different sizes = up to 4000 credits
Each size will be generated, optimized, and stored on our CDN when it is first accessed (by a visitor or by Googlebot, for example). If an older post or page isn't accessed then no image optimization credit will be used.
Up to 4,000 image optimization credits will be needed monthly regardless of how many times the images are accessed. A Short Plan ($4.99/month) will suffice.