By Erin Wright. First, we will go through the process in the new interface introduced to Adobe Acrobat in Adobe Creative Cloud You’ll find it at the top on the left. No, that's not possible, either. After uploading, Acrobat will automatically reduce the PDF size To reduce the size of your PDF file, open the Optimize PDF tool. Click the Tools tab at the top left, scroll down until How to Reduce PDF Size in the Old Interface. Method One. Open the PDF. Select the File StepOpen the Tools Tab. To