How to Manually Compress PDF and Reduce Its File Size

Xiaobai Software  2022-07-24 11: 51  read 52 views

PDF files can quickly become too large.Fortunately, many tools can make PDF files smaller and easier to share online.They'll help you the next time you hit your PDF file size limit.


We've compiled the best tools for compressing PDF files into four broad categories.

1. Adobe Acrobat Pro


If you have Adobe Acrobat installed on your computer, there is a tool in that application called "PDF Optimizer".This is one of the best and easiest ways to shrink PDF files.

To do this, open your PDF in Acrobat and click Tools > Optimize PDF.The Optimize PDF toolbar will appear right above the PDF.

If you click Reduce file size, you can choose to reduce single or multiple files.Next, you'll choose the location and name of the file.Once you hit save, Acrobat will apply default settings to your file in an attempt to reduce its size.

If you click on Advanced Optimization, you'll have more options to ensure you maintain the quality you need.To help you, in the "Advanced Optimization" window, click "Audit Space Usage" and you can see how much space each element takes up in the file.

Using default settings, our sample file shrunk from 11,775KB to only 212KB, makingAdobe Acrobat ProBe one of the most efficient PDF compressors on this list.Adobe Acrobat Pro DC will set you back $14.99 a month, but you can get a 7-day free trial.

2. Browser PDF Tool



If you want more control over the quality of your compressed PDFs, try DocuPub's NeeviaPDF (for files less than 24MB in size).

To keep things simple, you can choose a preset that ranges from low compression (for higher image quality) to maximum compression (for lower image quality).You can also choose to discard certain elements in your PDF.This includes things like tables, comments, and page tags that unnecessarily increase the file size.

Our sample PDF loses 98% of its size and is only 203KB, down from 11,775KB.This is the minimum we achieved in our tests, and the results look good.How much of the original PDF you want to throw away depends on how much space you really need to save.

3. Windows PDF Tools

Windows 10 finally includes an option to print to PDF.However, advanced features, such as adjusting the quality and size of files, are not part of this feature.Meanwhile, many PDF printers let you choose quality and compression settings, which can greatly affect the size of your PDF files.

Soda PDF Desktop


Soda PDF is a competitor to Adobe Acrobat Pro.While the free version is severely limited, when you upgrade to the pro plan, you can compress PDF files for $110 a year, though you can get up to 65% off when you reload the checkout page.When you download Soda PDF for the first time, you get a 7-day free trial.


To reduce the size of your PDF, open the file and go to Convert > Compress.This will bring up a menu where you can choose the compression level, from smallest to largest (file size).

At the smallest option, with file compression and image resampling set to 150dpi, our 11,775MB file was compressed to 261.53KB.This is about 98% smaller than the original PDF file, which is comparable to Adobe Acrobat Pro.When you install Soda PDF Desktop, it is best to reject any third-party software packaged with the installer.

Note that all tools listed below are requiredGhostscriptto view and process PDF files.


FreePDF is a classic PDF printer, and we emphasize it here because it allows you to create your own compression profiles.Once installed (remember, you'll need GhostScript), you'll find it's listed as part of Windows Printers.

To reduce the size of a PDF file with FreePDF, open it, press Ctrl+P to launch the print dialog, select FreePDF as your printer, click OK, and wait for the FreePDF dialog to pop up.Here, you can choose from three preset PDF profiles, including eBook, high quality, and medium quality.


To create a custom PDF profile, click Edit Profiles in the upper right corner, select Profile, click New, and customize the options available in the Profile Editor window.You can change the general quality of your PDF, adjust the default resolution of images within the PDF, or add a watermark to your PDF.


The default medium quality profile compresses a 10MB scanned PDF file to a 1.7MB PDF file with acceptable quality loss.

4Dots Free PDF Compress


This free application enables you to compress single or multiple PDF files in one fell swoop.You can also compress entire folders of PDF files with a few mouse clicks, even if those PDF files are password protected.

Once you have selected the files you want to compress (supports drag and drop), choose where you want to save the small files.You can overwrite the old file or save a copy.Click Compress and the tool will do all the work for you.Our five sample PDFs took a few minutes to compress and turned out to be 11.5MB or 29.5%.

Free PDF Compressor


This completely free software is also very simple to use.Select the file you want to shrink, click Compress, and save the smaller file.

Additionally, you can choose from five levels of compression, depending on how you want to use the file:

Low resolution (72dpi), suitable for screen viewing only

Medium resolution (150dpi), ideal for ebooks

High resolution (300dpi), ideal for printing

Prepress (300 dpi), ideal for prepress, including color preservation

Default value, ideal for various uses

Our single sample file finished in less than a minute, and due to the maximum compression level chosen, the result was only 276KB, down from 11,775KB.The final image quality is completely flawless.


IrfanView is a lightweight and feature-rich image viewer for Windows.It comes with a range of plugins that make it a versatile image editing tool, for example, convert images to different file types, add watermarks to your photos, and batch process images.It also has PDF printing capabilities, although not in the classic sense.

Before you can view PDF files with IrfanView, you need to install GhostScript.Then, when you try to save the oversized PDF as a new, smaller PDF, you'll see a PDF settings window next to the "Save PDF as..." dialog.Under "General", you may want to set "Preview PDF" in the save action to not required, so you can choose the settings right away.Then you can adjust the compression settings as shown in the image below:


In my tests, I selected medium quality for all image types, which reduced the size of a 10MB scanned PDF file to under 1MB.The result is noticeably blurry, but perfectly readable.

4. Mac PDF Tools

PDF Filter


If you frequently update your Mac's operating system, you should be able to shrink your PDFs without installing any new applications.This is a cool feature in OS X that a lot of people don't know about.

First, open your PDF in Preview.Normally, you can just double-click the file, but if you have a PDF reader such as Adobe Reader installed, you'll want to right-click > Open & > Preview).Then click "File" > "Export", and in the "Quartz Filter" drop-down box, select "Reduce file size".

This only works for large PDF files.Try doing this for a very small PDF file (less than a few MB) which may actually increase in size.

PDF squeezer


Apart from the simple process above, there really aren't many options for Mac users, reputable free PDF compression tools.If you want to control the output quality of compressed PDFs etc, your best bet is to download an app like PDF Squeezer ($5.99).

This is a relatively low-cost application that enables you to choose from a variety of predefined compression settings, or choose your own.You can also batch multiple files (including encrypted files) at once.

How to make a PDF smaller?

This is just the beginning of what you can do with your PDFs.From reading text in images and scanning files for malware to converting PDFs to other formats and unlocking password-protected PDFs, you can find the perfect PDF tool to help you.

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