Sharing a PDF from iPhone is one of those tasks that has six right answers depending on context. AirDrop to the colleague sat next to you. Email to a client. Cloud link to your accountant for a tax pack. Each works; each has gotchas.
The sharing is easy. What people miss is the prep — clean it up *before* hitting send.
The share sheet, demystified
Long-press any PDF in Files (or tap the share button in Mail's preview) and you get the standard iOS share sheet. Top row: AirDrop suggestions. Middle: messaging apps. Below: actions like Save to Files, Copy, Print (which can also Save as PDF via pinch-zoom trick).
AirDrop is fastest for nearby Apple devices. Mail attaches up to 25 MB; iCloud Mail Drop kicks in for bigger.
Compress before you send
If the PDF is over 10 MB, run it through compress PDF before sharing. Smaller files send faster on cellular, don't bounce on email limits, and don't make the recipient wait. A 30-second compression saves five minutes of upload time.
Cloud links for big or sensitive files
For PDFs over 25 MB, share an iCloud Drive or Google Drive link instead of an attachment. Save the file to the cloud folder, long-press, Share → Copy Link. Paste into a message. Recipients without an Apple ID can still open iCloud links via the web.
Sign or edit before sending
Sharing a contract? Sign it first. Sharing a form? Fill it in via edit PDF. Both run in Safari on iPhone, both finish faster than typing out 'please sign and return' for the third time.
FAQ
What's the maximum PDF size I can email from iPhone?
Apple Mail attaches up to 25 MB, but Mail Drop (iCloud) automatically handles up to 5 GB by replacing the attachment with a download link for the recipient. Other mail providers' limits vary — Gmail is 25 MB, Outlook is usually 20 MB.
Can I AirDrop a PDF to a Windows PC?
No — AirDrop is Apple-only. For PC recipients, use email, a cloud link (Drive, Dropbox), or upload via a browser. Snapdrop in Safari works as a free AirDrop-like cross-platform alternative.
Does AirDrop preserve PDF quality?
Yes. AirDrop transfers the file byte-for-byte — no compression or quality loss. The recipient gets the exact same PDF.
Before you hit share, give the PDF a thirty-second polish. Edit, sign, or compress in Safari.