How do I reduce the size of a PDF without losing quality?

To reduce PDF size while keeping good quality, start with the 'Low (High Quality)' compression setting in Acrobat. This option often reduces the file size by 10-30% because it skips re-compressing images. Text quality is never affected by compression, only images. Always work from your original file.

What is the difference between image quality for screen viewing versus printing?

Image quality for screens and print is different. For viewing on a screen or sending by email, images with 72-100 DPI are usually fine and look clear. However, for good quality printing, images need to be much higher, around 300 DPI. Using low DPI images for printing will make them look blurry or pixelated. Always match your compression settings to how the PDF will be used.

Why does compressing a PDF multiple times make the file worse?

Compressing a PDF multiple times makes it worse because each time you compress, more image data is removed or changed. This is like making a copy of a copy; each new copy loses more detail. To keep the best quality, always compress the original PDF document, not a file that has already been compressed before.

If my PDF has mostly text, will reducing its size affect the text quality?

No, if your PDF has mostly text, reducing its size will not affect the text quality. Compression in Acrobat only changes images, not text. Your text will always remain clear and sharp, no matter how much you reduce the file size.

Can I automate the process of reducing PDF file size for many documents?

Yes, you can automate reducing PDF file size for many documents using the Adobe PDF Services API. This API allows you to programmatically compress PDFs with different levels: LOW, MEDIUM, or HIGH. You can integrate this into your own systems to handle large batches of files efficiently.

◆ Acrobat · compress

Reduce size while preserving accessibility features

Every [event=audit] forces me to manually compress and reconcile archives. I want a repeatable delivery method that pr…

3ready prompts

1real task

3roles

See the prompt↓More compress workflows

When to use it

real situations

You need to email a PDF but the file is too big.
Your school asks for accessible documents, but you must shrink the PDF.
You want your online PDF to load faster for everyone, including those using screen readers.

AI prompts

3 ways to ask · copy any one

AExecute — “help me do it”Help me reduce the size of my PDF while keeping all...…+

Help me reduce the size of my PDF while keeping all accessibility features. The file is [describe PDF or upload].

when the reply comes backWant tips to check if your PDF is still accessible?

BImprove — “do it better”Suggest better ways to make my PDF smaller without losing...…+

Suggest better ways to make my PDF smaller without losing any accessibility features. My main concern is [speed/email/upload].

when the reply comes backNeed help understanding what makes a PDF accessible?

CDecide — “help me choose”Which method should I use to reduce PDF size and...…+

Which method should I use to reduce PDF size and keep accessibility, if I need the PDF for [school/email/website]?

when the reply comes backCurious about other ways to share large documents?

How to do it

the tool · the steps · what to avoid

1
Open your PDF file in Adobe Acrobat.
2
Go to the File menu and select Save As Other.
3
Choose Reduced Size PDF from the submenu.
4
Select the desired compatibility option in the dialog that appears.
CautionChoosing a lower compatibility may prevent older PDF viewers from opening the file.
5
Click OK to proceed.
6
Enter a new file name and location if prompted, then click Save.
Best practiceFor best results, always save the reduced file as a new copy to preserve your original PDF.

In the appWith the API

You can quickly reduce the file size of your PDF using the 'Save as Other' option in the File menu.

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

Glossary

words on this page

AccessibilityMaking sure everyone, including people with disabilities, can use something.ExampleThe website was designed with Accessibility in mind, so screen readers can easily navigate it.

PDFA common file type used to share documents that look the same everywhere.ExampleShe saved the brochure as a PDF so everyone would see the exact same layout and fonts.

Reduce SizeMaking a file smaller so it takes up less space.

Who does this

3 roles

Office AdministratorLegal AssistantProject Manager

FAQ

about this task

In Adobe Acrobat, you can use the 'Save As Other' or 'Optimize PDF' tools to make your PDF smaller. Make sure to keep accessibility settings turned on and avoid removing tags or important document structure. Always check the PDF after shrinking to confirm that screen readers and other assistive tools still work.

Accessibility features help people with disabilities read and use your PDF. If you remove these features while shrinking the file, some users may not be able to access the information. Keeping accessibility ensures everyone can use your document.

A common mistake is removing tags or document structure to save space, which makes the PDF harder for screen readers. Also, compressing images too much can make them blurry or lose their descriptions, which are important for accessibility.

Some free tools can shrink PDFs, but they may remove accessibility features like tags or alt text. Adobe Acrobat and other professional tools are safer for keeping accessibility, so always check the PDF after using any tool.

After shrinking your PDF, use Adobe Acrobat's 'Accessibility Check' tool to scan for issues. You can also try reading the document with a screen reader or ask someone who uses assistive technology to test it.