Certain aspects and settings of a PDF file affect the total size of a PDF such as the resolution, embedded manner, font type, etc.
Given below are few helpful tips to reduce PDF size:
1) Use the Save as Option
A very effective method to reduce PDF size, that many dont know, is to use the save as option. After you change your PDF file to your requirement, instead of choosing save, click Save As and put in the same filename. A message will come asking if you want to replace the existing file. Choose yes. If you just click Save, the changes are incorporated into the image which would lead to increased file size.
2) Use the PDF Optimizer
On the PDF file, go to Advanced, then click on PDF optimizer and click on Audit Space Usage. This is a useful tool that will help you find out which area of your PDF is taking how much space.
3) Manage your graphics
To reduce PDF size, graphics is an important factor to take into consideration. If you have graphic images in your PDF file, try and use vector based graphics as much as possible because vector based graphics take much lesser space then regular GIF images.
However, if it is absolutely necessary to insert a bitmap graphic file onto your PDF then make sure you adjust the resolution and compress the image drastically as bitmap files can increase your total PDF file size to a great extent. Compressing your bitmap images will definitely help to reduce PDF size.
For more advanced users, you can change your image quality and other settings by going to Advanced, then clicking on PDF optimizer. Here you can change grayscale, color and monochrome settings.
4) Color Management
If you want to post your PDF file on the Internet and if color is not an issue, then changing the RGB color scheme can be of great help to reduce PDF size.
5) Managing Fonts.
As fonts can take up a huge chunk of your PDF file size, you must make sure you do not embed the fonts on the PDF file.