How to Compress a PDF for Email Attachment (Gmail, Outlook, Yahoo)
Gmail caps attachments at 25 MB. Outlook is even tighter at 20 MB. Yahoo Mail tops out at 25 MB. If your PDF bounces back with "attachment exceeds maximum size," you have two options: pay for cloud storage, or compress the file. This guide does the second one — free, in your browser, in under 30 seconds.
The problem
You exported a contract, scanned receipt, or report from your phone or scanner, and the PDF is 30–80 MB. Email rejects it. You don't want to upload sensitive financial or legal documents to a third-party server. You need it small, now, and private.
Use the tool now
Open the compress pdf tool and follow the steps below.
Step-by-step
- 1
Open the PDFShed compressor
Click the embedded tool below or open the Compress PDF page directly. Nothing installs and nothing uploads — the work happens in your browser.
- 2
Drag your PDF in
Drop the file onto the upload area or click to browse. Files up to several hundred MB work fine; the browser handles them locally.
- 3
Pick a compression level
For email, "High Compression" usually cuts size by 60–85% with acceptable text and image quality. If you have only photos in the PDF, use "Aggressive."
- 4
Download the smaller PDF
When the green checkmark appears, click Download. Most 30 MB scans drop to 4–8 MB — well under any email cap.
- 5
Verify size before sending
Right-click the downloaded file → Properties (Windows) or Get Info (Mac) and confirm the size. If still too big for Outlook 20 MB, recompress with Aggressive once more.
Pro tips
- •Scanned PDFs compress hardest because images dominate. A 50 MB scan can drop to 3 MB without losing legibility.
- •Text-heavy PDFs (contracts, reports) compress less because text is already small. Aim for 50% reduction.
- •If the file still bounces, split it into two halves with our Split PDF tool and email each half separately.
- •For corporate-managed Outlook, your IT admin may have set a lower limit than 20 MB. Always check first.
Frequently asked questions
Is it safe to compress sensitive PDFs (tax returns, medical records)?
Yes — PDFShed processes everything in your browser using WebAssembly. Your file never leaves your device, never touches our servers, and is gone the moment you close the tab.
Why is my compressed PDF still too large?
High-resolution scans and embedded fonts can resist compression. Try the "Aggressive" preset, or use Image to PDF with reduced JPEG quality if the source is mostly photos.
Will compression damage the text or signatures?
Text remains crisp at all compression levels. Signatures (handwritten or digital) survive light and high compression but may soften under aggressive settings.
Can I compress a 100 MB PDF?
Yes. Browser memory is the only limit, and modern laptops handle 200+ MB files. If you hit a memory error, close other tabs and retry.