How to Compress PDF File Size without Losing Information

June 21, 2021Ashley Mae

Today, PDF is a widely used document file format to store text, images, graphic, table and more. However, the file size is a big problem. A PDF file can be hundreds of megabytes. If you are using PDF, you will find that it produces large files and takes a lot of space. That even blocks you to share your document online and send to your colleagues via email. That is why this article shares you several ways to compress your PDF files on PC and Mac.

Compress PDF

Part 1: Easiest Way to Compress PDF Online

Web apps are appealing and popular among internet users around the world. They allow you to perform plentiful of tasks without installing any software. Moreover, most web apps are free of charge with some limit, like file size. Aiseesoft Free Online PDF Compressor is the best choice to compress your PDF files online since can meet all your need and remove all limit.

How to Compress a PDF File Online for Free

Step 1:
Open a web browser and visit Then you will see the home page. There are two ways to upload a PDF. Click the Select PDF File button, find the large PDF and open it. Alternatively, drag and drop the PDF file into the box to upload immediately. It supports both PDF and scanned PDF files.
Step 2:
After uploading, the web app will begin compressing PDF immediately. When it is done, you will be taken to the download page.
Step 3:
Look at the compressed PDF size. Our PDF, for example, is reduced from 12MB to 2MB. If you are satisfied with it, click the Download the PDF button to get the smaller document. Or click the Compress Next PDF button to start compressing another PDF immediately.

Note: According to our research, it only takes a few seconds to upload and compress a PDF. However, the real time is depended on your internet connectivity.

Part 2: How to Compress PDF in Acrobat

Acrobat is the PDF solution from Adobe. It is able to compress PDF files on PC. However, the different editions of Acrobat will do the job in various ways. Bear in mind that the PDF compressing feature is only available to paid versions of Acrobat.

How to Compress a PDF in Acrobat Pro

Step 1:
Open a large PDF in Acrobat. If it is the default PDF reader, double-click on the document. Alternatively, right-click on the PDF file, choose Open with and select Acrobat.
Step 2:
Go to the Document from the top menu bar and choose Reduce File Size. You can also go to the File menu, choose Save As Other and choose Reduced Size PDF.
Reduce File Size
Step 3:
When prompted, select Acrobat Version Compatibility from the drop-down list and click OK to confirm it. Then you will get the Save as dialog. Enter the filename, choose a location folder, and click Save button.
Compress in Acrobat Pro

How to Compress a PDF in Acrobat DC

Step 1:
Firstly, you also need to open the PDF that you want to compress into Acrobat DC by clicking File and Open.
Step 2:
Then click the Tools menu and you will get the advanced tools in Acrobat. Click the Optimize PDF option to move on.
Optimize PDF
Step 3:
Now, you will get several tools under the top menu bar. Choose Reduce File Size or Advanced Optimization to trigger the PDF Optimizer dialog.
Compress in Acrobat DC
Step 4:
Change the settings related to images, font and more. Click the Audit space usage button at the upper right corner and you will see the PDF file size.
PDF Optimizer
Step 5:
Click OK and then hit OK to confirm PDF compression. Then save it as a new PDF file. We suggest you to keep the original PDF and not replace it with the compressed file.

Note: Acrobat DC is the latest version of PDF reader and editor. It is available to both Windows and Mac. The annual bill costs $179.88.

Part 3: How to Compress a PDF with Office Word

Office Word is a PDF editor as well. It is able to scan your PDF file and convert it to Word, so that you can change the text, add new graphics and do other editing. In fact, it provides more features related to PDF including compressing PDF files one by one.

Step 1:
Open a PDF in your MS Word or suppose you are going to save a document as PDF.
Step 2:
Go to the File menu at the top left side and choose Save As. That will open the Save-As dialog
Save As
Step 3:
Firstly, select a specific folder to save the compressed PDF file and write down the file name in the File name box. Click the drop-down option next to Save as type and choose PDF or relative one.
Step 4:
Make sure to select the Minimum size (publishing online) under the Optimize for section on the popup dialog.
Step 5:
As long as you are ready, click on the Save button to compress the PDF and export it to your hard drive.

Note: This way is only available to the PDF files produced by PDF editor or MS Word. It produces a fairly small file depending on the number of images in the PDF. The scanned PDF files cannot be compressed by Word since the file size won't change a lot.

Part 4: FAQs about Compressing PDF

Is there a PDF file size limit?

Generally speaking, there is only one limit in the PDF file size. The overall file size must be below 10GB as the cross-reference tables which define the PDF structure use 10 bits. Therefore, you'd better look at the PDF file, remove duplicate contents and compress it to save more space.

How to compress a PDF without Adobe?

Adobe Acrobat is a popular PDF reader, but the advanced features are only available in the paid version. That is why so many people look for the alternatives to Acrobat. When it comes to PDF compressing, you can use MS Word or online PDF compressor to do the job for free.

How do I learn my PDF file size?

Right-click on the PDF file in a folder, choose Properties and you will see the file size on the popup dialog. This works on all PCs and you do not need any extra software. When it comes to Mac, you can learn the PDF file size in Preview or Acrobat Reader.


This guide has shared three ways to compress your large PDF files and minimize your document without losing quality or data. If you already subscribe Acrobat DC, the PDF Optimizer will help you to do the job manually. MS Word, on the other hand, lets you compress the PDF file while exporting. If they are not available to you, Aiseesoft Free Online PDF Compressor is a good choice to produce smaller PDF file. More questions? Please write them down below this post.

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1.1 How to Compress PDF Files 1.2 Best Solutions to Split PDF Pages 1.3 How to Reduce the PDF Size 1.4 How to Crop PDF file 1.5 Password Protected PDF File 1.6 How to add Page Numbers to PDF 1.7 How to Free Highlight Text in PDF 1.8 How to Remove Watermark in Word 1.9 How to Rotate PDF 1.10 How to add Text to PDF 1.11 Compress PDF Size on Mac 1.12 Compress PDF in Adobe 1.13 Compress PDF Online 1.14 Shrink PDF
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