There are many reasons for this phenomenon, such as the most basic reason: the Word file itself is very large (including many pictures, etc. ), so it will naturally become "small" after conversion to PDF.

Secondly, there are two main reasons:

1, PDF file integrates fonts used in the document.

For example, machine A has a certain font, but machine B doesn't. If a uses this font in a Word document, machine B will replace it with other fonts. However, this will not happen to PDF documents, and its display has nothing to do with the system, which also reflects the strong compatibility of PDF from one side.

2.PDF is also different from Word in typesetting, so the generated file is larger than Word.

In addition, in order to "streamline" the PDF, the following points should be noted before conversion:

1, when importing pictures into Word, try not to copy/paste directly, but use the function of inserting pictures in Word to reduce the file size;

2. Before importing the picture, do some simple processing, such as converting the format (converting the BMP bitmap file into JPG or GIF format) or compressing the picture.

3. First use the optimization function of Office to "slim down" the Word file, and then turn it to PDF.