How do I choose the right compression level for my PDF?

First, think about where your PDF will be used. If it's for viewing on a screen or sending by email, 'Medium' or 'High' compression is usually fine. If you plan to print the PDF, choose 'Low' compression or 'High Quality' to keep images clear. Acrobat will offer options when you choose 'Reduced size PDF'.

If my scanned document looks blurry after I compress it, what can I do?

Try compressing the original scanned document again with a 'Low' or 'High Quality' setting. Avoid compressing a file that has already been compressed once. If printing, make sure the compression setting keeps images at 300 DPI or higher.

Compress Old Files in Adobe Acrobat — How-to & AI prompts

AI prompts

2 ways to ask · copy any one

AExecute — “help me do it”Archive records older than [days=seven years] into a compressed combined PDF package and move…+

Archive records older than [days=seven years] into a compressed combined PDF package and move it to Long-Term Storage to reduce clutter and costs per retention rules.

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

BImprove — “do it better”Consolidate old records for compliant archiving: combine the year's closed files into one…+

Consolidate old records for compliant archiving: combine the year's closed files into one compressed PDF, ensure file-level metadata includes retention end date and responsible unit, move the package to Long-Term Storage and record the archive action in the retention log so we can justify deletion later.

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

CompressTo make a file smaller in size.ExampleYou can compress the large image file to make it easier to email.

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.

OriginalThe very first version of your file, before any changes.ExampleAlways save a copy of the original presentation before making any edits.

The real tasks

the one, listed here

Archive old records into a compressed package so storage costs and clutter are reduced according to retention rules.

FAQ

about this task

First, think about where your PDF will be used.
If it's for viewing on a screen or sending by email, 'Medium' or 'High' compression is usually fine.
If you plan to print the PDF, choose 'Low' compression or 'High Quality' to keep images clear.
Acrobat will offer options when you choose 'Reduced size PDF'.

When you compress a PDF, especially with high settings, Acrobat reduces the quality of images inside the file. It lowers the 'DPI' (dots per inch) of the images. For example, it might change them from 300 DPI (good for print) to 72 DPI (good for screens). This saves space but makes images look blurry or 'pixelated' if you try to print them large or at high quality. Text is never affected, only pictures.

Try compressing the original scanned document again with a 'Low' or 'High Quality' setting.
Avoid compressing a file that has already been compressed once.
If printing, make sure the compression setting keeps images at 300 DPI or higher.

'Save a Copy' simply makes an exact duplicate of your current PDF file, keeping all its properties and size. 'Save as Other', however, offers more options to change the file's format or properties, like 'Reduced size PDF'. When you choose 'Reduced size PDF' under 'Save as Other', Acrobat actively processes the file to make it smaller, which is different from just making a copy.

It is important to compress from the original PDF file because each time you compress a file, its image quality can get worse. If you compress a file that has already been compressed, you are making the images even lower quality from an already degraded version. This makes the images look much worse over time. Always start with the best quality file you have.

Compress Old Files

When to use it

AI prompts

How to do it

Glossary

The real tasks

Who does this

FAQ

Sources

Adobe help