How to Compress a PDF for Email (Under 25MB or 100KB)

If you have ever tried to email a scanned contract or an image-heavy report, you have probably hit the dreaded 'attachment too large' error. Most email providers — Gmail, Outlook, Yahoo — limit attachments to roughly 25MB, and some corporate mail servers are far stricter. The fix is simple: compress the PDF before you attach it.

There are two ways to shrink a PDF, and choosing the right one matters. Lossless compression rewrites the file's internal structure and recompresses streams without touching image quality — text stays crisp and selectable. This is ideal for text documents and usually trims 10–30%. Lossy compression re-renders each page as a downsampled image, which can cut a scanned PDF by 70–90%, at the cost of selectable text.

To compress a PDF for email with PdfWill: open the Compress PDF tool, drop in your file, choose a compression level (Light for text, Recommended or Strong for scans and photos), and download. Because everything runs in your browser, your document is never uploaded to a server — important when the file is a contract, invoice, or anything confidential.

A few practical tips: if you only need to email a few pages, split the PDF first and compress the smaller file. If your target is a hard limit like 100KB, start with the Strong level and check the 'after' size shown on the result screen. And if recipients need to copy text out of the document, stick with Light compression so the text layer survives.

Compressing before sending is faster than uploading a huge file, kinder to the recipient's inbox, and — with an in-browser tool — completely private.