Decreasing File Sizes of Documents with Graphics

Any time you add graphics to a document, you are bound to increase the size and complexity of the document. Various WordTips subscribers have written over the years, frustrated that whenever they add graphics to their documents, the size of their documents increases way beyond what they think it should.

So, we did some controlled testing with various versions of Word. In each version, we started with an identical document, created from scratch. The document contained only text. Then, using the exact same JPG file, we started trying different methods of inserting the graphic into the document, just to see the effect on the document's file size.

I put the results of the testing into a table. The first two lines show the size of both the text-only Word file and the graphic. The rest of the lines describe the process by which the graphic was placed in the original file, what was then done, and the resulting file sizes. In those lines that say "insert inline," the graphic was inserted inline with the text by choosing Insert | Picture | From File.

In those lines that say "insert link inline," the graphic was placed by choosing Insert | Picture | From File, but then right-clicking on the Insert button and choosing Link to File. (In the case of Word 97, I made sure that the check boxes for linking were selected and that the graphic itself wasn't saved with the file.)

In those lines that say "paste inline," the graphic was copied from the Clipboard to the document by pressing Ctrl+V. (In the case of Word 97, pressing Ctrl+V would result in the graphic floating over the text. Because of this, in Word 97 I chose Paste Special and made sure the graphic was pasted inline with the text.)

For those lines that say "float," I selected the placed graphic and chose to float the graphic over the text, meaning it was no longer inline. If a line has "F9" in it, that means that I selected the placed graphic and press Shift+Ctrl+F9. (Some readers reported that using this key combination resulted in smaller document sizes.)

What conclusions can be drawn from this controlled test? First, you will get the smallest file sizes by making sure that you only insert a link to a graphic, not the graphic itself. Second, floating a graphic rather than placing it inline has no significant affect on the overall document file size. (If anything, a floating graphic results in a slightly smaller file size.)

Third, pressing Shift+Ctrl+F9 has no effect on the document size, with the exception of using the shortcut key on a graphic that was inserted as an inline link. The primary purpose of the shortcut key is to "unlink" fields. In other words, to permanently replace a field with the result of that field. When used on a graphic, the link to the graphic is replaced with the graphic itself. It is unclear why the same huge increase in file size is not indicated when first floating a linked graphic and then pressing Shift+Ctrl+F9.

Fourth, there is a huge difference in file sizes when you insert an image vs. pasting the same image. This happens because when you insert an image from a file, Word maintains the compression that was present in the original file. When you paste something from the Clipboard, it is converted internally to an uncompressed bitmap representation of the original graphic, and that is what gets placed. (Notice, for instance, that an inserted image in Word 2002 or 2003 has a file size of only 373 KB, and the file size of the same graphic pasted results in a file that is 3,958 KB, or over ten times larger.)

The same sort of problem crops up if you choose to insert a picture from a scanner or camera. Using Insert | Picture | From Scanner or Camera, the picture data is transferred to Word as an uncompressed data stream. You aren't inserting a JPG file; you are inserting straight data. This results in huge file sizes. It is better to use a different program (other than Word) to save the image from the scanner or camera to a compressed file type, such as JPG. You can then insert the file into Word, and the compression of that file is maintained, as described earlier.

You should also realize that if you decide to insert links to your graphics, that your resulting Word file becomes less portable than it would otherwise have been. The image links are just that: links to the image stored elsewhere on disk. If you send the document to someone else, and they don't have those graphic files in the same relative location to the document you just sent them, then they won't be able to see the graphics. In that case it is best to store the graphic files in the same folder as the Word document, and then send the entire folder to the other person.

One thing that our testing did not address is what can happen to document file sizes if you create a document (with graphics) in one version of Word and then save the document in a different version of Word. In general, if you save from a newer version of Word into a file format used by an older version, then the size of your document file can increase dramatically. For more information on this phenomenon, refer to the following articles in the Microsoft Knowledge Base:

http://support.microsoft.com/?kbid=224663
http://support.microsoft.com/?kbid=262464