I received a .maipdf file
Install MaiPDF, then open the file. Most documents do not require an account.
I want to protect a PDF
Protect it for free in MaiPDF, then send the .maipdf file through email, chat, cloud storage, or USB.
Free download
Get MaiPDF for your device
Free for senders and readers. Choose an app store or a direct installer.
Android
Install from Google Play or use the direct APK.
iOS
For iPhone and iPad from the App Store.
Windows
Use Microsoft Store or the direct installer.
macOS
Use Mac App Store or the signed DMG.
How it works
Protect, send, and open
No special sharing service is required. The protected file can travel through any normal file channel.
01
Protect
Choose a PDF and set expiry, device limits, recipient rules, and access controls.
02
Send
Share the new .maipdf file by email, messaging, cloud storage, USB, or any other method.
03
Open
The recipient opens it with the free MaiPDF app. Most files work without an account.
Still in control: the sender can pause or revoke access after the file has been shared.
For everyone
Document protection should not be enterprise-only
MaiPDF gives individuals, teachers, students, creators, small teams, and businesses the same simple way to protect and open shared documents.
Capture controls
Uses platform protection to limit screenshots and screen recording.
Device rules
Limit which devices and recipients can open a protected document.
Expiry and revocation
Stop future access by date, usage rule, pause, or revocation.
Trace watermark
Display a trace code that helps identify the source of a leak.
Questions
The essentials
Is MaiPDF really free?
Yes. Protecting and opening files are free. MaiPDF is built for everyday users, not only companies. If the app needs funding in the future, that may come from optional plans for high-volume use or light in-app advertising — not a fee for ordinary recipients to open files.
Do recipients need an account?
Usually not. Most files open without an account. Sign-in is only required when the sender restricts a file to specific people.
What is a .maipdf file?
It is a protected package created from a PDF. It keeps the document encrypted and applies the sender's access rules when opened in MaiPDF.
What if someone forwards the file?
Forwarding a copy does not automatically grant access. The same device, recipient, expiry, and revocation rules still apply.