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You click Send and get an error: the attachment is too large. Gmail accepts attachments up to 25 MB, Outlook.com up to 20 MB, and company or school mailboxes sometimes less. In two steps you can almost always get a PDF under that limit.
Why is your PDF so large?
- Scans and photos. A scanned page is really a photo. Twenty scanned pages can easily add up to 10 MB or more.
- High-resolution images in presentations, brochures or reports.
- Lots of pages together, for example after merging several documents.
A PDF with only text is rarely the problem: it usually weighs just a few hundred KB.
Step 1: compress the PDF
- Open Compress PDF and choose your file.
- Choose Balanced. That’s the best choice for most files.
- Click Compress and download the smaller file.
- Check the new size. Still too big? Try Strong. That gives the smallest file, but you’ll see some quality loss in photos.
Light, Balanced or Strong: which one?
Compressing only touches the images in your PDF: photos, scans and illustrations. Text stays real text, so it stays sharp, selectable and searchable. The three strengths differ in how far the images are reduced:
- Light keeps every image at its original resolution and only stores photos more efficiently. Best quality, smallest saving. Choose it when the file only needs to shrink a little.
- Balanced also reduces images to about 200 dpi, which is still sharp on a screen and on paper. For most files this is the right choice.
- Strong reduces images to about 144 dpi. That gives the smallest file. Text in scans stays readable, but photos look softer when you zoom in.
After compressing, the tool shows how much smaller the file got. If it didn’t get smaller, you get your original back unchanged.
Step 2: still too big? Split it
If compressing alone doesn’t do it, send the PDF in parts.
- Open Split PDF and choose your (compressed) file.
- Enter where to cut, for example 10, 20 to cut after page 10 and after page 20. Tip: divide the size in MB by your limit to see roughly how many parts you need.
- Download the zip, unzip it and send each part in a separate email, with “part 1 of 3” in the subject line.
Before sending, an attachment is converted to text, which makes it about a third larger. Depending on your mailbox, that extra size counts toward the limit. So stay well below it: with a 25 MB limit, a PDF of at most 18 MB is a safe choice.
A few more tricks
- Leave out unneeded pages with Delete pages, such as blank pages or attachments the recipient already has.
- Scan again at a lower resolution. For text, 150 to 200 dpi is usually enough; 600 dpi makes files needlessly heavy.
- Compress before you merge, or after. Both work. If you merge many scans, compress the merged file once at the end.
- You can also compress Word and PowerPoint files: the photos inside get smaller, the text stays editable.
Frequently asked questions
How large can an email attachment be?
That depends on your own mailbox and the recipient’s. Gmail accepts up to 25 MB per message and Outlook.com up to 20 MB, but company and school mailboxes sometimes have a lower limit, for example 10 MB. The lower of the two limits is the one that counts.
Is my PDF uploaded when I compress it?
No. PDFCommunity compresses and splits the file in your own browser. Your PDF only leaves your device when you email it yourself.
Will the recipient notice that the PDF was compressed?
With Light or Balanced usually not: text stays as sharp as before and photos look the same on a normal screen. With Strong, photos look a little softer when you zoom in.
My PDF barely gets smaller. What now?
Then it contains few images to shrink, for example because it’s mostly text. If the file doesn’t get smaller, you simply get your original back. Splitting the file or leaving out unneeded pages is then the best solution.