How to Compress a PDF for Email (Under the Attachment Limit)
Compress PDFShrink PDF file size for email and uploads. Free, no sign-up.Email has an attachment limit, and a scanned contract or a PDF full of photos often goes over it. The email bounces, or the app refuses to attach the file. The fix is usually a minute of compression.
Check the limit first
The limit counts the whole email, and attachments grow by about a third when they are sent, so aim a little under it.
| Email service | Limit for attachments |
|---|---|
| Gmail | 25 MB |
| Outlook.com | 20 MB |
| Yahoo Mail | 25 MB |
| Many company mail servers | 10–20 MB (ask your IT team) |
Services change these numbers from time to time, so check yours if you are close to the limit. Upload forms (job portals, government sites) are often much stricter: 2 MB or even 1 MB.
Compress the PDF
- Open Compress PDF and choose the file. It is processed in your browser and never uploaded.
- Choose a level:
- Light for documents that are mostly text. The file stays sharp; text-only PDFs often shrink little, because they were already small.
- Recommended for scans and documents with photos. This is the right choice most of the time.
- Strong when you need the smallest file, for example for a 2 MB upload form.
- For black-and-white scans, turn on grayscale as well. Colour is often what makes scans heavy.
- Compare the new size shown on the page with your limit, then download.
Good to know: Recommended and Strong redraw pages as images, so text on those pages can no longer be selected or searched. Keep the original if you need searchable text later.
Still too big?
- Send only what is needed. Use Split PDF to send the pages the recipient asked for, or split a long scan into two emails.
- Shrink the photos before making the PDF. If you build the PDF from photos, compress them first with Compress Image and then put them into a PDF with JPG to PDF.
- Share a link instead. For very large files, a link from the cloud storage you already use avoids the limit altogether. That is a choice between you and your provider; openWorkstand does not upload files anywhere.
Before you press send
- Open the compressed PDF and check that small print is still readable.
- Name it clearly (
2026-10 Contract - signed.pdf) so the recipient knows what it is. - If it contains personal data, consider protecting it with a password and sharing the password another way.
After downloading, choose Save to Workstand to keep the sent version next to the project or client it belongs to.