The Problem: Email Attachments Have Size Limits
Almost everyone has faced this situation: an important PDF needs to be sent by email, but the attachment is too large. Most email providers limit attachment sizes to 25 MB (Gmail, Outlook) or even less. Some recipient servers refuse large attachments entirely based on their own limits, regardless of what your provider allows.
Most commonly affected: technical documents, architectural plans, presentations with graphics and multi-page reports with high-quality images. But there are several effective solutions.
Solution 1: Compress the PDF
Often the simplest approach is also the most effective. PDFs frequently contain images at unnecessarily high resolution, unoptimised fonts or redundant metadata that inflate the file size. Good compression can reduce file size by 50 to 80 percent without visible quality loss.
The PDF compression tool analyses the file and reduces image resolutions, removes unnecessary objects and optimises the internal structure. The result can be previewed in the browser before downloading.
Tip: Always check the compressed file to ensure all content remains legible, small text and fine graphics can lose sharpness with aggressive compression settings.
Solution 2: Split the PDF
If compression alone is not enough, splitting a long document into several smaller parts helps. A 60-page report can be divided into three parts of 20 pages each, all of which fall below the attachment limit.
With the PDF split tool, you specify where the document should be divided. Send the parts in separate emails with clear labelling (Part 1/3, Part 2/3 etc.) so the recipient knows what they receive and how to reassemble the parts.
Solution 3: Cloud Storage and Download Links
Instead of sending the PDF directly as an attachment, upload it to a cloud service and share the link. Benefits: no size restriction, the recipient can access the most current version, and you can revoke access if needed.
Suitable services include Google Drive, Dropbox, OneDrive or WeTransfer. WeTransfer is particularly handy for one-off transfers without an account, files up to 2 GB can be uploaded for free and shared as a link valid for 7 days by default.
Solution 4: FTP or Secure File Transfer
For regular large file exchanges in business environments, FTP servers or dedicated file transfer services are a good option. Managed File Transfer (MFT) solutions add encryption, access logging and automatic notifications, important for GDPR-compliant data exchange with clients and partners.
Solution 5: Send Only Relevant Pages
Sometimes a large PDF contains sections that are irrelevant to the recipient. Extract only the relevant pages and send them as a smaller PDF. The extract pages tool allows you to select specific pages or page ranges from a PDF and save them as a new, smaller document.
Images and Embedded Graphics as the Main Cause
The primary reason for oversized PDFs is almost always embedded images. When exporting a PDF from Microsoft Office, images are included at full resolution by default. For screen viewing, 96 to 150 dpi is entirely sufficient, 300 dpi is only needed for professional printing. Adjust export settings in Office or your PDF software to match the intended use.
Security Note for Email Transmission
Email is not a secure transmission medium. If you are sending confidential documents, protect the PDF with a password before sending, and communicate the password through a separate channel (such as by phone or SMS). This prevents intercepted emails from being directly readable.
Conclusion
For most everyday cases, compression is sufficient. Anyone who regularly shares large documents should consider cloud links. For particularly sensitive content, encrypted transmission is advisable. With the right tools and a thoughtful workflow, the file size problem is permanently solved.