How to make a PDF small enough to email or upload

Last updated: 1 November 2026

To make a PDF small enough to email or upload, compress it with Compress PDF at the “Recommended” level. If it is still too big, try “Extreme compression” or split it into several parts with Split PDF. Everything runs in your browser, so your file is not uploaded to a server.

This guide is for anyone whose email provider rejects an attachment or whose online form says the file is too large. Attachment limits differ by provider. Check what your provider or form allows before you start, so you know how small the file needs to be.

Open Compress PDF

Step by step

Check the size and the limit. Look at the file size of your PDF and compare it with the limit of your email provider or form. This tells you how much smaller the file has to get.
Select your PDF. Open Compress PDF and click “Select PDF files”, or drop one or more PDFs onto the page.
Choose “Recommended”. Keep the “Recommended” level, which balances size and quality. Choose “Less compression” instead if image sharpness matters most.
Compress the file. Click “Compress PDF”. Your browser compresses the file on your device, and nothing is uploaded.
Check the new size and download. Compare the new size with your limit, then click “Download”. If you compressed several files, you can save them together as a ZIP.
Go stronger if needed. If the file is still too large, run it again with “Extreme compression”. You can also tick “Convert to grayscale” or set the image resolution and JPEG quality under “Advanced settings”.
Split what is left. If compression is not enough, open Split PDF and cut the PDF with “Every N pages” or “Custom ranges”. Then send the parts in separate emails or uploads.

If the file is still too large

Compression shrinks images and tidies the file structure. It does not rewrite fonts or text. When the result is still over your limit, these options help:

Drop pages you don’t need. Every page you remove makes the file smaller. Use Remove PDF pages to remove pages you don’t need, or Extract PDF pages to keep only the pages you need, then compress the result.
Use grayscale. If the reader doesn’t need colour, tick “Convert to grayscale”. Colour photos and colour text become gray, which saves more space.
Set the values yourself. Under “Advanced settings”, lower the image resolution (dpi) and JPEG quality. This is free, like every level.
Send it in parts. In Split PDF, choose “Every N pages” to cut the document into equal parts, or click the scissors between pages wherever a new file should start. Click “Download all (ZIP)” to get every part at once.

Sending photos or scans as a PDF

If you are turning phone photos of receipts, ID cards or signed forms into a PDF, use JPG to PDF. JPG images are placed in the PDF exactly as they are, without re-compression. Because of that, the PDF can be about as large as the photos themselves.

In JPG to PDF, click “Select images” and put the photos in order.
Choose A4 with a small margin instead of “Same as image”.
Click “Convert to PDF”, then “Download”.
Run the new PDF through Compress PDF to make it smaller.

Need to send several PDFs as one attachment? Combine them with Merge PDF first, then compress the merged file. Merging copies pages as they are, so compress last.

Why some PDFs barely shrink

How much smaller a file gets depends on what is inside it. Most of the size of a scan or photo-heavy PDF is usually in its images, so those files often shrink by half or more. PDFs with only text, or with images that are already low resolution, may hardly change.

Some image types are left untouched to avoid damaging them, such as CMYK images and black-and-white scans in special formats. You never get a file bigger than the original. If the file can’t be made smaller, you get the original back unchanged. In that case, splitting is the practical way to get under the limit.

Tools used in this guide

Frequently asked questions

How big can an email attachment be?

It depends on your provider. Attachment limits differ by provider, so check your provider’s rules. Online forms often set their own, lower limits, for example 200 KB or 1 MB.

Can I compress a PDF to an exact size, like 1 MB?

No. There is no option to enter a target size. Start with “Recommended”, then try “Extreme compression” or set the resolution and JPEG quality under “Advanced settings”. Check the new size before you click “Download”.

Will compressing make my PDF blurry?

Text, vector drawings and fonts are never changed, so they stay sharp. Only large photos are resized and re-compressed. Choose “Less compression” if image quality matters most.

Is my file uploaded when I compress it?

No. Your browser compresses the file on your own device. The page is also blocked from sending files to any other site.

Is there a file size limit?

There is no fixed limit and no daily limit. The real limit is your device’s memory. Very large files of hundreds of megabytes work best on a computer and can be slow on phones.

Can I compress several PDFs at once?

Yes. Select or drop more than one PDF in Compress PDF, then save the results together as a ZIP. No account or sign-up is needed.

Your files are processed in your browser and are not uploaded. See the privacy policy.