Many email providers limit attachment size to 25 MB or less. If your PDF is too large to send, compressing it is the solution. This guide explains why PDFs get big, how to shrink them without losing important content, and how to use our free tool to reduce PDF size for email.
PDF file size depends on what's inside the document. High-resolution images, embedded fonts, and uncompressed graphics can make a PDF many megabytes. Scanned documents are especially large because each page is stored as an image. Text-only PDFs are usually small, but once you add photos or complex layouts, the size grows quickly. Compression reduces file size by optimizing images and removing redundant data while keeping the document readable.
Go to our Compress PDF tool. No sign-up or account is required. The tool runs entirely in your browser, so your file is never uploaded to a server—important when the document is sensitive or confidential.
Select the PDF you want to reduce in size. The tool will show the current file size. Many documents can be compressed by 30–50% or more with minimal visible loss in quality, especially for text-heavy files. Image-heavy or already-optimized PDFs may see smaller gains but are still worth trying.
When compression is complete, download the new file. Use it as your email attachment instead of the original. If the file is still too large, you can run it through the compressor again, or consider splitting the document and sending it in multiple emails using our Split PDF tool.