How to make a PDF smaller for email

Gmail allows attachments up to 25 MB, and many business mail servers and portals only 5–10 MB. Here's how to make your PDF fit and still look good.

Why is the PDF so big?

Almost always because of images. A scanner or phone captures every page as a high-resolution photo, and the PDF stores them as-is. Text on its own takes up very little.

Step by step

1. Open the Compress PDF tool and drop in your file.
2. Choose "Recommended" — images are brought down to about 150 DPI, which is enough for both screens and printing documents.
3. Click Compress. You'll see the old and new size and the percentage saved.
4. If it's still too big, run it again with "Strong compression".

Which level should I choose?

• Lossless — when the file must stay identical (e.g. a signed document someone will verify).
• Recommended — for most scans, contracts and reports.
• Strong — when all that matters is fitting the attachment limit and it will be read on screen.

If you make PDFs from phone photos, shoot the document in daylight and compress before sending — the difference is often 10×.