Fastly Image Optimizer vs MozJPEG

Fastly Image Optimizer automates image processing and delivery for image-heavy sites and apps. It resizes, adjusts quality, crops or trims, changes orientation, converts formats, and serves images on demand at the edge. Transformations are made in real time from request parameters, avoiding the need to pre-generate and store multiple variants. Processed images are cached for reuse. Supported formats are WebP, AVIF, JPEG, and PNG; developers control resizing, quality, format, and cropping through query parameters and configuration. The service integrates with existing asset pipelines and CMS platforms while teams keep their current image sources. It can be enabled through the Fastly control panel or API, while Compute SDK access is available through a beta program. Pricing includes 100,000 image requests per month at free. Paid rates are billed per 10,000 image requests and vary by monthly volume, from $0.50 a month for 100,000–10 million requests to $0.01 a month beyond 5 billion. Every request sent to Image Optimizer, including through the SDK, counts as billable.

MozJPEG is a free, open-source library project that improves JPEG compression efficiency to produce smaller files and higher visual quality. It is intended for graphics programs and image-processing tools, and programs using the libjpeg API can integrate it without MozJPEG-specific integration code. It is compatible with the JPEG standard and the vast majority of deployed JPEG decoders. When converting other formats to JPEG, it uses trellis quantization to target the quality-to-file-size ratio. Its progressive encoding with jpegrescan optimization can losslessly reduce the size of a JPEG when used with jpegtran. The project’s improvements can be disabled at runtime, returning it to libjpeg-turbo behavior. The repository includes a demo cjpeg command-line tool, which is not intended for serious use. Build instructions cover Unix-like systems, macOS, Linux, and Windows with Visual C++ or MinGW. The GitHub repository identifies version 4.1.1 on its latest release page. MozJPEG points users to libjpeg-turbo documentation for additional build help; its repository does not state security certifications or compliance claims.