In many cases, Mac users already have an equivalent tool pre-installed on their operating system: the Preview app. Beginners will need to experiment a little here, as parameters that are too strict can prevent you from printing images or using forms. For example, this allows you to delete useless objects, reject user data, or adjust the transparency of images. If you are confident enough, you can also determine the compression parameters yourself. It does this by removing unused fonts, reducing the resolution of images, and deleting unnecessary elements.
If you choose the “Standard” option, Acrobat Pro will complete an efficient compression, in which the program will attempt to create the smallest possible file size without significantly compromising quality. There are various tools for belated compression, which will be briefly introduced and explained in the following section. However, this is commonly the most inconvenient method, because a belated reduction of the resolution is always made at the expense of image quality – even if the loss of image data is curtailed enough that a clear result is achieved.
If you have an already-completed PDF in front of you, or you aren’t the creator of the file, you usually can’t avoid a belated compression if you prefer a smaller file size. On the other hand, for a printing template or presentation, you shouldn’t go lower than 150 dpi, and 300 dpi would be optimal. If it only needs to be read on a computer screen, 72 to 96 dpi are sufficient. When choosing a resolution, you should always consider the purpose for which the PDF file is being created.
This is best done through picture editing programs like Photoshop or Gimp.īesides the measurements and color depth, the most important factor when doing this is the image resolution, which is indicated in units called “dpi,” or “dots per inch.” Halving the resolution from 600 dpi to 300 dpi noticeably reduces the size of a PDF, from approximately 4.55 megabytes to 2.68 megabytes. Pictures especially should be compressed in advance. Here, a simple rule applies: less information means a smaller file size. Ideally, you should try to keep a PDF document as small as possible even in the initial process of creating it. PDFs of a manageable size are also advantageous in the online application forms of large companies, as many corporations set a strict megabyte-limit for documents that are to be submitted.
Nevertheless, the free mailboxes of many e-mail providers offer limited storage space and only allow attachments between 4 and 35 megabytes in size to be sent. If you want to e-mail text documents in the form of Word files, it is certainly a good idea to first convert them into PDF form. This provides a contrast to Word documents, for example. Formatting and fonts are firmly embedded in a PDF document, which allows for reproductions that are true to the original on all devices. When considering the process of moving files to an external storage device like a USB stick, the factor of transfer speed makes an additional valid argument.įurthermore, PDFs are often sent as e-mail attachments. First, the most obvious: a reduced PDF file saves storage space on the hard drive. Still, there are many benefits that speak to the value of having as small a file as possible.
Since the PDF format doesn’t have concrete page-length or storage restrictions, a large file is generally not a problem.