WD98: Change in Document File Size Is More or Less than Expected

Sometimes the file size of your Word document changes substantially (increases or decreases), even if you make only minor revisions to the document. Moreover, the file size sometimes remains constant, even though you made changes in the document. These changes in file size are a result of the Fast Save feature.

The file size of your Word document may increase unexpectedly if the Allow Fast Saves option is turned on. A fast save appends the changes to the end of your document, which increases the size of the document. By contrast, when you turn off the Allow Fast Saves option and save the document, Word performs a full save, which incorporates all your revisions (instead of appending them). If you perform a full save after a file was fast saved, Word rewrites the file thus reducing the size of the file.

Even with the Allow Fast Saves option turned on, Word periodically performs a full save of your document. As a result, the file size of your document may change substantially between save operations.

NOTE: If you open a document from a previous version of Word, Word may temporarily allocate more disk space for the document than is actually necessary.

To disable the Allow Fast Save feature, follow these steps:

1. On the Tools menu, click Preferences.
2. Click the Save tab.
3. Click to clear the Allow Fast Saves check box.

For additional information about this situation in earlier versions of Word, please see the following article in the Microsoft Knowledge Base: