Some PDF documents need to be split into pieces. Maybe the file is so large that it would overwhelm available bandwidth when posted online. Maybe one large editing project needs to be divided into smaller tasks split among several employees. Maybe the file includes multiple documents that were concatenated out of convenience but were never intended to be merged as a single document. In all cases, Adobe Acrobat Pro can help; the current version of the software now includes a Split Document command that allows users to break up large files into smaller PDF documents.
Splitting a PDF File
Open a multi-page PDF file in Adobe Acrobat Pro.
Study your document to decide how best to split it. Acrobat will split it based on one of three options that you can set: a fixed number of pages, a fixed output file size or between bookmarks. If, after studying your document, you decide it best to divide based on bookmarks, and if no bookmarks exist, you must set them. Open the Bookmarks Navigation Panel ("View" > "Navigation Panels" > "Bookmarks") and use that interface to insert bookmarks where needed. Keep in mind that you must bookmark every portion of the document that you want split into its own file. This may take some time; on the other hand, it offers the most control over the output documents.
Start the splitting process by selecting "Document" and "Split Document." A dialog window appears displaying three options: Number of Pages, File Size, Top-level Bookmarks. Choose one of these. The Number of Pages and File Size options include fields to enter the number of pages or number of megabytes for each output file. Acrobat applies these uniformly across the document; if the number of pages or file size does not divide evenly into the original document, the last of the output files will contain the remainder. The third option, Top-level Bookmarks, allows for finer tuning than the others. If you've organized the document using bookmarks, this option tells Acrobat to create a file for each span of pages between marks. "Top-level" means that Acrobat will disregard nested bookmarks when splitting.
Click the "Output Options" button in the lower left of the dialog window. In the Target Folder area, select "Same folder as originals" or "Specific Folder." If you choose "Specific Folder," Acrobat will prompt you to choose a folder. In the "File Labeling" area you can choose how to name the files created by the split operation. The option "Use bookmark names for file names" will be available if you chose the "Top-level Bookmarks" option earlier. The other options permit you to fine-tune the output document names using a custom label, which you can position before or after the original file name in the new file. You can also choose a custom separator character or characters that Acrobat places between the original file name and the label.
When finished selecting options, click "OK" on both the "Output Options" and "Split Document" dialog windows. Acrobat writes the new files to the folder you selected with the naming options you chose.