Compress a PDF to send it by email (Gmail and Outlook limits)
The scenario is familiar: you attach a PDF to an email and your mail service rejects it because it exceeds the allowed size. Each provider has its own limit, and a scanned or image-heavy document reaches it fast. The good news: most of these files can be slimmed down in seconds, often with no visible difference.
This guide gives the exact limits of the main email services, the steps to compress a PDF, and the fallbacks for when the file is still too heavy — all without uploading your document to a server.
The real limits of email services
Gmail caps attachments at 25 MB (beyond that it automatically offers a Google Drive link). Outlook and Microsoft 365 usually limit to 20 MB, often less in a company setup. Yahoo Mail sits around 25 MB. Note that these limits apply to the whole email, encoding included, which cuts the usable size by roughly a third. A 20 MB PDF can therefore be rejected even though it seems under the limit. Aiming for 15 to 18 MB maximum is a safe margin.
Compress the PDF in seconds
Open the Compress tool, drop your file and run the optimization. Compression rewrites the document structure and re-encodes images at a sensible resolution: a 30 MB scan often drops to a few megabytes with no visible loss on screen or in normal printing. Then check the result — crisp text, readable images — before sending. Since the file is not uploaded, the operation is instant even on a large document.
If the file is still too heavy: split it
When compression is not enough (a document of hundreds of pages, very high-resolution scans), the solution is to split the PDF into parts and send them across several emails, or to send only the pages that matter. The Split and Delete / Extract pages tools let you isolate exactly what the recipient needs — often a 200-page attachment comes down to the 10 pages that are actually required.
Alternatives when direct sending is impossible
If the document must stay whole and heavy, it is better to share a link (via a storage service) than to force the attachment. But for a confidential document, keep in mind that dropping a file on a third-party service means entrusting it to them. Compressing and sending only what is strictly necessary remains the safest approach: less data transmitted, less exposure.