How to Compress a PDF for Email (Fit Under 25 MB, Free)
Gmail and Outlook cap attachments at 20–25 MB. Here's how to shrink a PDF by up to 90% right in your browser — free, no watermark, no upload.
You hit send, and the email bounces back: "attachment too large." Gmail allows 25 MB, Outlook 20 MB, and many company mail servers even less. Scanned PDFs blow past those limits easily because every page is a full-resolution photo. The fix takes under a minute.
Why scanned PDFs are so large
A text-based PDF stores letters and fonts, which are tiny. A scanned PDF stores an image of every page — often 2–5 MB per page at typical scanner settings. A 10-page scan can easily reach 30–50 MB. Compression re-encodes those images at a smarter quality level, which is why savings of 50–90% are normal for scans.
Compress it in 3 steps
- Open the Compress PDF tool and drop your file in — it is processed on your device, not uploaded.
- Pick a level: "Balanced" for most emails, "Smallest" when the limit is strict.
- Check the new size shown before downloading, then attach and send.
Still too big? Split it instead
Contracts with hundreds of scanned pages sometimes will not fit even after compression. In that case use Split by size — it cuts the file into parts that are each under the limit you set (for example 15 MB), always at page boundaries, so you can send part 1 and part 2 in separate emails.
Tips to keep quality readable
- Preview before sending — MyPDF shows the result so you can confirm text is still sharp.
- Compress the original, not a re-scan — every extra scan generation loses quality.
- For documents that must stay pixel-perfect (engineering drawings, medical images), send a download link instead of compressing aggressively.
Frequently asked questions
How much smaller will my PDF get?
Scanned PDFs typically shrink 50–90%. Text-based PDFs are already small, so expect modest savings there.
Does compressing remove my text or signatures?
No. All pages and content stay — only the internal images are re-encoded at a more efficient quality.
Is my file uploaded to a server?
No. MyPDF compresses the file inside your browser on your own device, so confidential documents never leave your hands.