How do I make my PDF file smaller without losing quality?

Go to File > Save as Other > Optimized PDF. In the Optimizer, choose settings like downsampling images to 150 dpi for color/grayscale and 300 dpi for black and white. Set JPEG quality to Medium/High (around 85%) as this often looks good to most people. Review your choices and save the file.

What is the difference between downsampling and unembedding fonts when optimizing a PDF?

Feature What it does Impact on File Size. Downsampling Images Reduces the resolution (detail) of pictures in your PDF. Significantly reduces file size, especially for PDFs with many high-resolution images. Unembedding Fonts Removes the font data from the PDF. The viewer's computer must have the font. Can reduce file size, but might change how text looks if the font is not available on the viewer's system.

Reduce Prefill Rework in Adobe Acrobat — How-to & AI prompts

AI prompts

1 way to ask · copy any one

DBecome — “help me grow”I've prefilled roughly 60 engagement templates this year and each required corrections from…+

I've prefilled roughly 60 engagement templates this year and each required corrections from attorneys about billing clause variants. Show the pattern in which clauses are changed most often, recommend one improvement to our template or intake capture that would cut those edits by two-thirds, and explain how to implement it with minimal disruption.

when the reply comes backPush once: ask it to sharpen the weakest part, and to say what it assumed.

How to do it

the tool · the steps · what to avoid

1
Open your PDF file in Adobe Acrobat.
2
Select the File menu, then choose Save as Other and then Optimized PDF.
3
In the PDF Optimizer dialog, review the default settings under each panel (such as Images, Fonts, Discard Objects, Discard User Data, and Clean Up).
4
Adjust any settings as needed, or leave them at their defaults for a basic optimization.
5
Click OK to apply the optimization and choose a location to save the optimized PDF.

In the appWith the API

You can preview the estimated file size reduction before saving by clicking the 'Audit space usage' button in the optimizer dialog.

This runs in the Acrobat app - there is no separate API for this task.

Glossary

words on this page

DownsampleTo make an image smaller by removing some of its detail, which reduces the file size.ExampleTo make a large photo fit an email, you might downsample it to reduce its file size.

Unembed fontsTo remove the font information from a PDF, making the file smaller but requiring the font to be on the viewer's computer.ExampleYou unembed fonts from a PDF to reduce its file size before emailing it to a colleague.

OptimizeTo make something work better for a specific use.ExampleYou optimize your website images to load faster for visitors with slower internet connections.

Who does this

3 roles

Graphic DesignerAdministrative AssistantMarketing Coordinator

FAQ

about this task

Go to File > Save as Other > Optimized PDF.
In the Optimizer, choose settings like downsampling images to 150 dpi for color/grayscale and 300 dpi for black and white.
Set JPEG quality to Medium/High (around 85%) as this often looks good to most people.
Review your choices and save the file.

PDF Optimizer is a tool in Adobe Acrobat that helps you make your PDF files smaller. It matters because smaller files are easier to share, upload, and store, especially when you have many documents or slow internet.

If your scanned PDF becomes blurry after optimizing, it means the settings were too strong. Go back to the 'Optimize PDF' tool and this time, use the 'Optimize Scanned Pages' option. This feature is designed specifically for scanned documents and helps keep them clear while reducing size.

You should use RGB colors for PDFs viewed on a screen because computer monitors and digital displays use RGB (Red, Green, Blue) to show colors. CMYK (Cyan, Magenta, Yellow, Key/Black) is for printing. Using RGB for screen viewing ensures colors look correct and can also help keep the file size smaller.

Feature	What it does	Impact on File Size
Downsampling Images	Reduces the resolution (detail) of pictures in your PDF.	Significantly reduces file size, especially for PDFs with many high-resolution images.
Unembedding Fonts	Removes the font data from the PDF. The viewer's computer must have the font.	Can reduce file size, but might change how text looks if the font is not available on the viewer's system.

Reduce Prefill Rework

When to use it

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How to do it

Glossary

The real tasks

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FAQ

Sources

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When it fails