The version of Preview included with OS X 10.3 could play animated GIF images, for which an optional button could be added to the toolbar. As of OS X 10.4, Preview lost playback functionality and animated GIF files are display as individual frames in a numbered sequence.
Features
Editing PDF documents
Preview can encrypt PDF documents, and restrict their use; for example, it is possible to save an encrypted PDF so that a password is required to copy data from the document, or to print it. However, encrypted PDFs cannot be edited further, so the original author should always keep an unencrypted version. Some features which are otherwise only available in professional PDF editing software are provided by Preview: It is possible to extract single pages out of multi-page documents, sort pages, and drag & drop single or multiple pages between several opened multi-page documents, or into other applications, such as attaching to an opened email message.
Editing images
Preview offers basic image correction tools using Core Image processing technology implemented in macOS, and other features like shape extraction, color extraction, cropping, and rotation tools. When annotating images, Preview uses vector shapes and text until the image is rasterized to JPEG, PNG or another bitmap format. PDF and image documents can also be supplied with keywords, and are then automatically indexed using macOS's system-wide Spotlight search engine.
Import and export
Preview can directly access image scanners supported by macOS and import images from the scanner. Preview can convert between image formats; it can export to BMP, JP2, JPEG, PDF, PICT, PNG, SGI, TGA, and TIFF. Using macOS's print engine it is also possible to "print into" a Postscript file, a PDF-X file or directly save the file in iPhoto, for example scanned photos. Beginning with Mac OS X 10.7 Lion, Preview restricts the Format option popup menu in the Save As dialog to commonly used types. It is possible to access the full format list by holding down the Option key when clicking the Format popup menu.
New features in Version 7
A new "edit button" where the picture can be edited is introduced in Version 7. The "edit button" allows options to insert shapes, lines, do cropping, and among other things.
Issues
As of OS X 10.9.2, Preview does not support ISO-standardized PDF, and when saving, destroys aspects of PDF files without warning to the user.
