Compressing PDF Files


Optional. Enable any of these values by adding it to the profile and setting it equal to "on."

subset-embedded-fonts Subsetting fonts removes unused characters from font files embedded in the PDF.

It is a best practice when working with PDF documents to embed all of the fonts used in that document into the document itself. That way, the viewing tool (like Acrobat) does not have to look for a font on the local system, or choose a substitute. But embedding font files in a PDF document can make the PDF quite large, especially if the PDF has embedded a font file for an Asian language, such as Mandarin, with tens of thousands of characters.  To avoid this, a subset of the characters in the font can be saved in the PDF document. The subset font only includes the characters you expect to need when rendering the pages of that document. This often leads to a much smaller PDF.

consolidate-duplicate-fonts Remove multiple copies of the same font file.

Sometimes PDF documents are created with multiple copies of the same font, either as multiple subsets or multiple, fully embedded copies of a font file. When multiple copies of the same font appear, they may be merged into a single font.

unembed-standard-14-fonts Remove the Base 14 fonts.  The Base 14 fonts are:

  • Times Roman
  • Helvetica
  • Courier
  • Symbol
  • Times Roman bold
  • Helvetica bold
  • Courier bold
  • ZapfDingbats
  • Times Roman italic
  • Helvetica oblique
  • Courier oblique
  • Times Roman bold/italic
  • Helvetica bold/oblique
  • Courier bold/oblique

When these standard fonts are embedded in a PDF document they can make the file larger.

resubset-subset-fonts Allows already subset fonts to be re-subset if possible (see “subset-embedded-fonts” above). Subsetting can significantly reduce the size of the PDF document if a font features thousands of glyphs, such as Mandarin. By re-subsetting a subset font in a PDF document, you are replacing it with a subset that will only contain the glyphs currently in use in the document.

Suppose you have a long PDF document that uses Mandarin characters. You decide to create a summary version of this file by deleting all but the first two pages. After re-subsetting, the Mandarin characters that no longer appear in the document are removed.

remove-unused-fonts Removes fonts that are embedded but not being used in the document.