PDF Too Large to Email? 3 Free Ways to Send It

What the attachment limit actually is

Every email provider caps how much you can attach to one message. For the big free services, Gmail and Outlook.com, the limit is around 20 to 25 MB. Work and school accounts may have different limits set by the organisation, and the exact figures change from time to time, so check your provider's help page if you are close to the edge.

There are two details that catch people out:

• Attachments grow in transit. Email encodes files as text before sending, which makes them noticeably larger than they appear on your computer. A file that looks like 19 MB on disk may be rejected by a 20 MB limit.
• The receiver has a limit too. Your provider might let you send 25 MB, but if the recipient's company mail server only accepts 10 MB, the message bounces back, sometimes hours later.

Some providers offer to turn large attachments into a cloud link automatically. That works, but the recipient then needs access to that cloud service and the link permissions need to be right. If you want the file to arrive as a normal attachment, you need to make it smaller or split it.

TipAs a rule of thumb, aim for attachments that are comfortably below 15 to 20 MB in total. For recipients at large organisations or government offices, smaller is safer, so aim for well under 10 MB if you can.

Option 1: Compress the PDF

Compression is the cleanest fix because the recipient still gets one file. Open Compress PDF, add your file and start with the Recommended level. For scanned documents and reports with lots of photos, this often cuts the size dramatically, because most of the weight in those files is pictures saved at a much higher resolution than anyone needs on screen.

If Recommended is not enough, try Strong. If your file is a typed document with few images, try Lossless, which cleans up the structure without touching picture quality. Typed PDFs are usually small already, so if one of them is huge, the cause is often a few large embedded images or fonts.

When you have a precise number to hit, such as 'under 10 MB' for a client's mail server, Target-size PDF is quicker. Enter the size and it tries picture compression first, keeping text selectable, and only rasterises pages if that is the only way to reach the target.

If you also need to hit a small limit on an application portal, our guide on compressing a PDF to 100 KB, 200 KB or 1 MB goes deeper into what quality to expect.

Option 2: Split the PDF into parts

Some files cannot be compressed enough without becoming unreadable: architectural drawings, high-quality design portfolios, long scanned case files. In those cases, splitting is better than crushing.

Split PDF by size lets you set a maximum size per part, for example 15 MB, and then cuts the document into as many pieces as needed, keeping pages in order. You can then send each part as a separate email. If you would rather split by chapter or page range, the regular Split PDF tool lets you choose exactly which pages go into each file.

• Name the parts clearly, for example Tender-Documents-Part-1-of-3.pdf, so the recipient can put them back in order.
• Send the emails in order and mention in the first one how many parts are coming.
• If the recipient needs one combined file, they can join the parts again with Merge PDF. Our guide to merging PDF files explains how.

Watch outSplitting a document across several emails increases the chance that one part lands in spam or gets missed. For anything important, ask the recipient to confirm they received every part.

Option 3: Share a link instead

For very large files, or when you need to share the original full-quality version, upload the PDF to cloud storage you already use and send a link. This avoids attachment limits entirely and lets you replace the file later if you spot a mistake.

Before you hit send, check the sharing settings carefully:

1. Who can open it? 'Anyone with the link' is convenient but means anyone the email is forwarded to can open it. For private documents, restrict access to specific email addresses.
2. Can they edit it? For most documents, view-only is right.
3. How long should it stay up? Some services let you set an expiry date. Use it for sensitive files.
4. Does the recipient's organisation block it? Some offices block certain cloud services, so a link that works for you may not open for them.

Links are a good fit for portfolios, large reports and files you share with a team. For legal notices, tender submissions or anything where you need proof of exactly what was sent, a proper attachment is often expected, so compress or split instead.

Which option should you choose?

You can also combine them. A common pattern is to compress first, and if the result is still slightly too large, split it into two parts rather than compressing harder.

Prevent the problem next time

A few habits keep PDFs email-friendly from the start:

• Scan at a sensible resolution. For documents that will be read on screen, around 150 dpi is usually enough. Use higher settings only when you need to print or zoom into fine detail.
• Use greyscale for text documents. Colour scans of black text on white paper are much heavier and rarely more readable.
• Export from Word or PowerPoint with a smaller image setting. Office apps often have an option to optimise for online use or minimum size. If formatting is your worry, see our guide to converting Word to PDF while keeping formatting.
• Compress pitch decks before sending. Presentations with full-resolution photos are a common culprit. Our guide to compressing a pitch deck covers that case.
• Remove pages nobody needs. Delete blank or duplicate pages with Organize PDF before compressing.

Because all of these tools run inside your browser, you can use them on confidential files such as contracts, invoices and payslips without uploading them anywhere.