Mac OS X ships with a PDF reader called Preview. Preview is a very decent PDF reader which also allows you to view edit images (editing capabilities are very limited), but if you’re looking for a PDF reader that is dedicated to making your PDF reading experience more simple and powerful, then Skim is what you’re looking for.
There are many reasons why I prefer Skim to Preview when it comes to PDFs, especially e-books or long PDF files, in general. Skim was designed to help you read PDFs just like the way you read and interact with a hard copy of a document, file or book.
- Full Screen Reading and Zoom to Fit – This is probably the most ridiculous limitation in Preview. Whenever I’m reading an e-book or a PDF document that is over 20-30 pages long, I like to lay back and read it in full screen mode. With the Zoom To Fit feature in Skim (Cmd + =) I get exactly the kind of reading experience I want. This is a rather trivial feature to implement, I have no idea why it is absent in Preview. Here are two screenshots – The first shows Preview in its fullscreen ‘Slideshow’ mode, and the second shows Skim in its Full Screen mode, with Zoom to Fit turned on.
- Support for in-line notes – While reading a document or book, you can create inline notes to add study notes or a reminder to yourself. These notes can be saved along with the PDF, and will appear at the same position as you saved them, the next time when you open the PDF. Note that the actual PDF is not modified, the notes are stored in a separate ‘Skim Notes’ file. Thus, you won’t see those notes if you open the PDF with another application.
Preview has support for Notes too, but only anchored notes (a small image linking to the actual note which appears in the sidebar, outisde the PDF) which again, is pretty limited in application.
- Full Window Maximize rather than ‘Optimize’ – If you click the small green button on the top left corner of the window in Skim, it ‘maximizes’ the window so that it takes up all the available space on the screen. In Preview, the same button does an ‘Optimize’ function, which is rather unpredictable, and annoying to some, as it resizes the window based on the size of the content (image or PDF) to be displayed.
- Visual Contents – Along with the normal textual ‘Table of Contents’, Skim has an option for displaying ‘Visual Contents’ which displays a small thumbnail of each page in the sidebar. This can be especially useful when you are looking for something, you don’t remember what was written on that page, but you remember what it looks like.
These are some features that make Skim a better option over the default Preview.app that ships with Mac OS X. Do try it out, and tell us what you like about it, or what you don’t like about it in the comments.