FileSpin provides two ways to transform and display images on-the-fly:-

Using Standard Image Conversion - Standard Image Conversion is a default image conversion generated for all images. FileSpin uses this Standard Image Conversion as source image to provide the transformed output image. These dynamically transformed images do not use any storage quota. For example, when you request a 300x300 resize of an image asset via a URL such as https://cdn.filespin.io/api/v1/assets//conversions?resize=300,300 , the resize transformation is generated on-demand and delivered instantly.
Using Custom Image Conversion - Custom Image Conversions are pre-generated and stored according to the image settings in User account. These Custom Image Conversions can be used for Dynamic image transformations.