How do I reduce the size of a PDF in Adobe Acrobat?

Open your PDF in Adobe Acrobat. Go to the menu and select 'Save as Other'. Choose 'Reduced Size PDF'. Pick a compression level (start with Low). Save the new file with a different name.

What is the difference between Low, Medium, and High compression in Acrobat?

Compression Level Image Quality File Size Best For. Low (High Quality) Images stay clear 10-30% smaller Printing, keeping quality Medium Images a bit less clear Smaller than Low Email, web upload High Images can be blurry Smallest size Quick sharing, not for print

Create Compact Backup in Adobe Acrobat — How-to & AI prompts

AI prompts

2 ways to ask · copy any one

AExecute — “help me do it”Compress the 200-page report into a compact PDF under email size limits, verify visual fidelity…+

Compress the 200-page report into a compact PDF under email size limits, verify visual fidelity of charts, and save the smaller file for emailing remote stakeholders later today.

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

BImprove — “do it better”Before emailing, make the compressed backup trustworthy—produce a compressed [pdf] plus a…+

Before emailing, make the compressed backup trustworthy—produce a compressed [pdf] plus a separate high-res extract of complex [charts], add a cover [page] noting compression artifacts, and ensure all critical [tables] remain legible so recipients don't request a resend.

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 the PDF you want to archive in Adobe Acrobat.
2
Select File > Save As Other > Archivable PDF (PDF/A).
CautionPDF/A conversion may remove features like audio, video, and JavaScript that are not permitted in archival PDFs.
3
In the PDF/A conversion dialog, choose the desired PDF/A standard (such as PDF/A-1b for basic long-term preservation).
Best practicePDF/A-1b is widely accepted for basic archival needs, but check your organization's requirements.
4
Click OK to convert and save the PDF as a PDF/A file.
5
Open the newly saved PDF/A file.
6
Select File > Save As Other > Reduced Size PDF.
7
In the Reduce File Size dialog, select the desired compatibility level (choose the lowest version that meets your needs for maximum compression).
Best practiceFor archival, using the lowest compatible version maximizes compression but may reduce compatibility with very old PDF viewers.
8
Click OK and save the reduced-size PDF/A file.
Best practiceBefore archiving, use File > Properties to remove unnecessary metadata and hidden data for further size reduction.

In the appWith the API

After converting to PDF/A, always review the document to ensure all essential content remains accessible and readable.

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

Glossary

words on this page

CompressionMaking a file smaller by removing some data, often from images.ExampleApplying image compression reduced the photo's file size without losing too much quality.

DPIDPI means dots per inch, and it tells you how clear an image is when it is scanned.ExampleA scanned photo saved at 300 DPI will usually contain more detail than the same photo at 72 DPI.

Original fileThe first, untouched version of your PDF before any changes.

The real tasks

all 2, listed here

Create a compact backup of a 200-page report so it can be emailed to remote stakeholders

Create a compact archive of legacy configuration docs so I can keep them but reduce storage use.

FAQ

about this task

Open your PDF in Adobe Acrobat.
Go to the menu and select 'Save as Other'.
Choose 'Reduced Size PDF'.
Pick a compression level (start with Low).
Save the new file with a different name.

PDF compression means making the file smaller by lowering the quality of images or removing extra data. This is important because smaller files are easier to share, upload, or email. However, too much compression can make images look blurry, especially if you want to print the PDF. Always choose a compression level that matches how you plan to use the PDF.

Yes, if your scanned PDF is already blurry, compressing it more will make the images even less clear. Compression lowers image quality, so always check your PDF after shrinking it. If you need to keep details, use Low compression or keep the original for printing.

Compressing a PDF again and again makes the images worse each time. Each round of compression removes more detail, so the pictures get more blurry or pixelated. Always start with the original file for the best results.

Compression Level	Image Quality	File Size	Best For
Low (High Quality)	Images stay clear	10-30% smaller	Printing, keeping quality
Medium	Images a bit less clear	Smaller than Low	Email, web upload
High	Images can be blurry	Smallest size	Quick sharing, not for print

Create Compact Backup

When to use it

AI prompts

How to do it

Glossary

The real tasks

Who does this

FAQ

Sources

Adobe help