This tutorial shows you how to work with the Scan and Optimize features in Acrobat X. See what the all-new Acrobat DC can do for you.

Download a free trial of the new Acrobat.

How to optimize your PDF file using Acrobat X

Learn how to OCR PDF by using the PDF Optimizer to reduce the file size of PDF files and speed up download times.

By Annamarie Lukes – February 17, 2011


In this tutorial, learn how to OCR PDF by using the PDF Optimizer in Adobe Acrobat X Pro or Suite to reduce the file size of PDF files and speed up their display or download times.

View transcript

How to optimize your PDF file using Acrobat X

Annamarie LukesFebruary 17, 2011

As more people have access to high speed internet, their impatience with files that take a long time to open or download has grown.

You can significantly speedup your PDF files with Acrobat X Pro's PDF Optimizer.

PDF Optimizer provides many settings to help you reduce the size of PDF files and speed up their display or download times.

PDF Optimizer can also help create PDF files that are more efficient to distribute in a print production workflow.

While you can easily reduce file sizes by simply going to File>Save As>Reduced Size PDF, the only control you have over how the reduction is accomplished isthe ability to choose Acrobat version compatibility from the dropdown list.

The newer the version you select, the greater the potential file size reduction.

To get to PDF Optimizer, simply go to File>Save As>Optimized PDF.

PDF Optimizer lets you customize exactly how you reduce the size of a PDF.The settings you choose will depend on how you intend to use the file.

For example, the image compression you select for a PDF that will be posted onlinewill be very different from the image compression you select for a PDF in a print production workflow.

The first thing you will want to do when you open up PDF Optimizer is to select the button in the upper right that says "Audit space usage".

In the auditreport that comes up, I can see that in this PDF images make up 91.8 percent of the file size so that is clearly where I should spend my efforts in trying toreduce the size.

The next thing to do is go to the Settings options on the upper left and choose a setting.

Acrobat X Pro comes with two preconfigured settings, Standard and Mobile.

Or you can create your own Custom setting.

Once you have created some custom settings, you can save them with a unique name so that you can come back at any point in the future and go directly to those settings.Next I choose the Acrobat version compatibility that I want.

I can see near the top left that my current PDF version is Acrobat 8 and then I can go over to the compatibility settings and choose from Acrobat 4 up through Acrobat X.

The later the version you choose, the better the compression you will be able to achieve.

However, you will want to select a version that you think will include the majority of your viewers.

Now for the fun part.

There are six different panels in the PDF Optimizer dialog box that you can work with to reduce the size of a PDF.

The Images panel of PDF Optimizer lets you set options for color, grayscale, and monochrome image compression, and image downsampling.Downsampling reduces file size by lowering the resolution of images, whereas image compression reduces file size by eliminating unnecessary pixel data.

In general, JPEG 2000 and JPEG give better results on photographs and ZIP is the better choice for illustrations with large areas of solid, flat color.

For monochrome images, JBIG2 compression is superior to CCITT.In the Fonts panel you can save space in a PDF by unembedding the fonts but then there are no guarantees that people viewing your PDF will see it as youintended.

A better choice is to subset all embedded fonts.

That way you retain the look of your PDF without carrying the overhead of characters that are notbeing used.

If your PDF includes artwork with transparency, you can use the presets in the Transparency panel to flatten transparency and reduce file size.

The Discard Objects panel and the Discard User Data panel let you specify objects and data to remove from the PDF.Finally, the options in the Clean Up panel remove useless items from your document.

When you have finished making all your choices in PDF Optimizer, select the OK button on the bottom right.

Then in the Save As dialog box that comes up, I would definitely give your file a new name so that you can always go back to the source file in case there was something you didn't like about what you didin your optimized PDF.

If you want to see detailed information on every element in PDF Optimizer, go to the Adobe Acrobat X Pro Help file.Now that you know how to optimize a PDF, the last thing I want to let you know is that you don't have to go through the same step by step method for every filein the future.

You can create an Action to automate the process.

Products covered:

Acrobat X

Related topics:

Compress PDF online, Scan and Optimize

Top Searches:


Comments for this tutorial are now closed.

Lori Kassuba

2, 2016-01-29 29, 2016

Hi David,

Thanks for letting us know you where you tracked it down.



7, 2016-01-22 22, 2016

Thank you, Lori

I did manage to find where the settings were saved in Windows. I found this link: with a simple javascript to locate the folder.

It’s worth pointing out that the subfolder depends on the version. We’re not migrating to DC any time soon, so it’s either 10.0 or 11.0.

On a Mac (my system) it’s in: ~/Library/Application Support/Adobe/Acrobat/11.0/

Lori Kassuba

5, 2016-01-22 22, 2016

Hi David,

In the PDF Optimizer dialog, you can create and save a preset. The preset is saved your User folder under [username]/AppData/Roaming/Adobe/Acrobat/DC/Preferences/PDF Optimizer.

One way to distribute across multiple machines is to package up Acrobat using the Customization Wizard with this particular file included.



3, 2016-01-21 21, 2016

I know you can save these settings as a preset for later use. But how do you export those settings for distribution and use on other machines?


2, 2013-03-17 17, 2013

Very good this tutorial.


7, 2013-03-12 12, 2013

Great and informative.  I wish there was an option to print the transcript or the pdf option available to save.

Comments for this tutorial are now closed.