Secure Transfer · Workflow
Send a PDF Securely Without the Copy Trail.
Email attachments stay in sent folders, inboxes, provider archives, and mail clients — for years, on systems you don't control. Send an encrypted link instead. The recipient decrypts in their browser, and the file self-destructs on your schedule.
Learning how to send a PDF securely without attaching it to email? Encrypt the file in your browser, share a short link, and let it expire on your schedule — no recipient signup, no lingering inbox copies, no server-side plaintext.
lockEncrypted in your browser
scheduleExpires in 24 h or 30 d
person_offNo recipient account needed
What's wrong with just emailing the PDF?
When you email a contract, a medical record, or a tax statement, you're copying it to at least four systems you don't control: the sending mail server, intermediate relays, the recipient's provider, and every device their mail client syncs to. None of those copies have an expiration date. None of them are encrypted at rest by default. And forwarding is one click away.
Three things email doesn't do — and PDF Pro does
The gaps email leaves wide open, closed by default:
- Email leaves plaintext on every hop. PDF Pro encrypts the file in your browser before anything is uploaded.
- Attachments live forever. Our server stores ciphertext it cannot decrypt — even with full database access.
- Forwarding is one click away. Share links expire on a schedule (24 h free, 30 d Pro), and the ciphertext is deleted when they do.
Why PDF Pro instead of other tools
The differences that matter for sending a PDF securely — all real, not marketing.
Your file never lives on a mail server
Email attachments are stored plaintext on every relay they touch. A Secure Transfer link stores ciphertext we can't decrypt.
Link expires on a schedule you set
Email attachments live in inboxes and archives for years. Secure Transfer ciphertext is deleted when the link expires.
No recipient account needed
The recipient clicks and decrypts in their browser — no signup wall between them and the file.
Local encryption, honest storage
Encryption happens in your browser before upload. Our server sees ciphertext and nothing else — not the file, not the key, not the passphrase.
How to send a PDF securely
Four steps from drop to expiring link.
1
Drop the PDF
The browser encrypts it with AES-256-GCM using a key you own.
2
Pick a mode
Fragment mode: the key rides in the URL hash. Passphrase mode: PBKDF2-derived, share the passphrase out-of-band.
3
Share the link
The recipient clicks, their browser decrypts locally, and they download the file.
4
Set expiry
Default 24 hours (free) or up to 30 days (Pro). Optional single-use flag deletes ciphertext after the first decryption.
When to reach for an encrypted link
Cases where "attachment" is the wrong default.
Signed NDA to a vendor
Avoid leaving copies on every mail server between you and the vendor's IT department. If you still need to edit terms before sending, convert the document to an editable Word version first.
Medical document to a specialist
Send without creating a portal account. Flag single-use so the ciphertext deletes after the first download.
Tax documents to an accountant
Link dies after download. No personal financial data living in four mailboxes for the next five years.
Security boundary (read this)
- Anyone with the full link can decrypt in fragment mode. Treat the link like the file itself.
- For higher assurance use passphrase mode and share the passphrase through a separate channel (phone, Signal, in-person note).
- Zero-knowledge means we genuinely cannot recover the file — not for you, not with a warrant, not with root database access — because we never received the key.
- To sign the document with verifiable integrity before sending, see our cryptographic PDF signing whitepaper.
Honest limitations
- No recovery path — feature of zero-knowledge. Lost link or forgotten passphrase means the file is gone.
- File size cap: approximately 25 MB per transfer on the free tier.
- Secure Transfer is not a DLP replacement for a regulated enterprise environment (no server-side logging, access policies, or audit trail we can promise).
Related tools
Frequently asked questions
Is sending a PDF via encrypted link safer than email?
Yes — email attachments are unencrypted at rest on intermediate servers, and your recipient's mail provider may retain your attachment for years. Secure Transfer ciphertext has an expiry date and our server cannot read it. That said, "safer" is about the threat model — if your recipient forwards the decrypted file to someone untrusted, no transport-layer security helps. For the full architecture, read our zero-knowledge file transfer technical overview.
Does the recipient need to sign up or create an account?
No. Recipients click the link, their browser decrypts locally, and they download the file.
Can I make the link work only once?
Yes. The single-use flag deletes the ciphertext immediately after the first successful decryption.
What if I lose the link or forget the passphrase?
The file is permanently unrecoverable. Zero-knowledge encryption means there is no override — we never had the key.
Can PDF Pro be legally compelled to hand over my file?
The server stores encrypted bytes and an initialization vector (plus, in passphrase mode, a salt). None of that can decrypt the file without the key, which we never receive. We can only hand over ciphertext — which is what we have. For the full cryptographic architecture, see how zero-knowledge PDF transfer works end-to-end.
What's the maximum PDF size I can send?
Approximately 25 MB per transfer on the free tier. Pro supports larger files.
How do I send a PDF securely to someone outside my company?
Drop the PDF into PDF Pro, pick fragment mode (key in the link) or passphrase mode (share the passphrase separately), and send the link. Recipients outside your company don't need a PDF Pro account — they click and their browser decrypts locally. No IT approval, no portal signup, no attachment trail. If you need to adjust the content first, run a quick PDF to Word conversion before encryption.
Is there a free way to send a PDF with encryption?
Yes. PDF Pro's free tier supports sending a PDF securely with AES-256-GCM encryption and 24-hour link expiry — no signup required. The free-tier file cap is approximately 25 MB per transfer; Pro extends the expiry window to 30 days and raises file limits.
Stop shipping sensitive PDFs as attachments.
Send one encrypted link. Let it expire on a schedule. No account required to receive.
sendSend an Encrypted Link