How to Compress a PDF for Email and Uploads
Updated October 9, 2026
Email services usually limit attachments to about 20 to 25 MB, and many online forms accept even less. A PDF full of photos or scanned pages can easily be larger than that. Here is how to make it smaller without making it unreadable.
Why are some PDFs so large?
The biggest cause is images. A scanned document is just a picture of each page, and phone photos inserted in a PDF can be several megabytes each. Text alone is tiny. Embedded fonts add a little more.
How to compress a PDF in 4 steps
- Open the Compress PDF tool and choose your file.
- Choose a mode. Light keeps your text selectable and gives a small saving. The Strong modes give a much smaller file by saving each page as an image.
- Press Compress PDF.
- Look at the message with the before and after size, check the preview, and download the file.
Which mode should I choose?
- Light for documents that are mostly text, when you still need to copy or search the text.
- Strong, high quality for photos and brochures where the pictures must stay clear.
- Strong, medium or smallest for scans and forms where you only need a file small enough to send. Try medium first, and use smallest only if the file is still too big.
Strong modes turn pages into images, so the text can no longer be selected or searched. If you need searchable text again, run the OCR PDF tool on the result.
More ways to reduce size
- Delete pages you do not need with the Delete PDF Pages tool.
- If the file contains large photos, shrink the photos first with the Compress Image tool, then create the PDF from them.
- Split a very large file into two parts and send them in two emails.
Frequently asked questions
Will compression make the text blurry? In Light mode the text is unchanged. In Strong modes it can look a little softer at the lowest setting, so check the preview.
What if the result is not smaller? Some PDFs are already optimized. Try a Strong mode.
Are my files uploaded? No. Everything happens in your browser.