How can I make my PDF file size smaller without losing quality?

Open your PDF in Acrobat and go to File > Save as Other > Optimized PDF. In the 'Images' section, set color/grayscale images to about 150 dpi and monochrome to 300 dpi. Choose 'JPEG quality Medium/High' (around 85%) for images. In the 'Fonts' section, select 'Subset embedded fonts' and 'Unembed fonts' if not needed. Remove unnecessary objects and user data under 'Discard Objects' and 'Discard User Data'.

What is 'downsampling' in PDF optimization and why does it matter?

Downsampling means reducing the number of pixels in an image within your PDF. It matters because fewer pixels mean a smaller file size, which helps the PDF load faster. You can control how much quality you lose by choosing the right 'dots per inch' (dpi) setting.

If my PDF is a scanned document, how should I optimize it?

If your PDF is a scanned document, you should use the 'Optimize Scanned Pages' option in Acrobat. This tool is designed to work specifically with scanned content, which often has different characteristics than digitally created PDFs. It can help clean up and compress scanned images more effectively, making the file smaller and clearer.

What is the difference between RGB and CMYK colors when optimizing a PDF for screen viewing?

Color Model Best Use File Size Impact. RGB (Red, Green, Blue) For on-screen viewing (websites, emails) Generally smaller file size CMYK (Cyan, Magenta, Yellow, Black) For professional printing Generally larger file size

Why should I unembed fonts when optimizing a PDF?

You should unembed fonts to make your PDF file smaller. When fonts are embedded, the font data is stored inside the PDF. If the viewer already has those fonts on their computer, unembedding them removes this extra data, reducing the file size. However, be careful, as unembedding can sometimes change how the document looks if the viewer doesn't have the correct fonts.

Optimize PDF for mobile device viewing in Adobe Acrobat — How-to & AI prompts

AI prompts

3 ways to ask · copy any one

AExecute — “help me do it”Please optimize this PDF for mobile viewing by...…+

Please optimize this PDF for mobile viewing by making the text and images easy to read on small screens. The file is [insert PDF name or upload].

when the reply comes backWant tips for making PDFs easier to read on phones?

BImprove — “do it better”Can you improve this mobile PDF by making...…+

Can you improve this mobile PDF by making the layout simpler and the text larger? The current file is [insert PDF name or upload].

when the reply comes backNeed help shrinking the file size for faster downloads?

CDecide — “help me choose”Should I use single or double columns for...…+

Should I use single or double columns for the best reading experience on mobile devices in my PDF? My document is about [brief topic].

when the reply comes backWould you like to add clickable links for mobile users?

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, then choose Optimized PDF.
3
In the PDF Optimizer dialog, select Mobile from the Make compatible with dropdown if available; otherwise, proceed to manually adjust settings for mobile optimization.
NoteSome Acrobat versions may not have a dedicated 'Mobile' preset; manual adjustments are recommended for best results.
4
Under Images, reduce the resolution to 96 or 150 dpi and set compression to JPEG or JPEG2000 with medium quality.
Best practiceLowering image resolution significantly reduces file size without major loss of quality on mobile screens.
5
In the Fonts section, unembed fonts that are standard or commonly available on mobile devices.
NoteUnembedding fonts reduces file size but may affect appearance if the font is not available on the device.
6
Check the Discard Objects and Discard User Data sections to remove unnecessary elements like metadata, hidden layers, and comments.
7
Review the Clean Up options and enable removal of invalid bookmarks and unused elements.
8
Click OK to apply the optimization settings.
9
Save the optimized PDF with a new name to preserve your original file.
Best practiceTest the optimized PDF on an actual mobile device to ensure readability and performance.

In the appWith the API

Optimizing for mobile viewing ensures your PDF loads faster and displays clearly on smartphones and tablets.

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

Glossary

words on this page

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.

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

Mobile DeviceA small, portable device like a smartphone or tablet.ExampleShe used her smartphone to check emails while waiting for the bus.

The real tasks

the one, listed here

Replace a large hero image with a compressed version so the page loads faster for users on slow connections.

FAQ

about this task

In Adobe Acrobat, you can use the 'Optimize PDF' tool to adjust the file for mobile viewing. This makes the text and images easier to see on small screens by changing the layout and sometimes reducing the file size.

Optimizing a PDF for mobile devices means changing the document so it is easier to read and use on phones or tablets. This usually involves making text bigger, simplifying the layout, and making sure images fit well.

Optimizing your PDF helps make sure the person can read it easily on their phone. If you don’t, the text might be too small or the layout could look messy, making it hard to use.

Yes, you can open both files and look at them side by side. You’ll notice that the optimized PDF is usually easier to read on a small screen, with bigger text and a simpler layout.

If you saved a copy of your original PDF, you can always go back to it. It’s a good idea to keep the original file before making any changes.

Optimize PDF for mobile device viewing

When to use it

AI prompts

How to do it

Glossary

The real tasks

Who does this

FAQ

Sources

Adobe help

Other guides

When it fails