How to Sign a PDF on iPhone, Android, Mac, or Windows
No matter which device you use, whether it’s iPhone, Android, Mac, or Windows, signing a PDF should be simple, fast, and secure. With a modern e signature platform like SignBox, you can sign documents online in minutes without downloading apps or installing software.
Whether you’re closing a deal, approving a contract, or reviewing an NDA, the process is the same across all devices: upload → sign → download.
Why Signing PDFs Digitally Works on Any Device
Digital signing removes the limitations of device type or operating system.
When you sign a PDF online, you get:
- Consistent signing experience on all devices
- No printing or scanning
- Faster agreements
- Secure and organized file management
- Instant access from your browser
Whether you’re on the go with a phone or working from your computer, digital signing keeps everything simple.
How to Sign a PDF with SignBox on Any Device
You can sign a PDF using SignBox from iPhone, Android, Mac, or Windows. The steps are identical because everything works directly in your browser.
Step-by-Step
- Open SignBox in your browser.
- Click Upload Document and select your PDF.
- Choose My Signature to create your e-signature
– draw, type, or upload your handwritten signature. - Place your signature where needed on the PDF.
- Download the signed PDF or store it securely in SignBox Drive.
No app installation is required, just a device with a browser.
Try SignBox now for Free →
Device-Specific Notes
iPhone & Android
- Works from Safari, Chrome, or any mobile browser
- Perfect for signing documents on the go
- Receive signature invitations instantly via email
- Tap to sign in seconds
Mac & Windows
- Works on Chrome, Safari, Firefox, and Edge
- Drag-and-drop upload for your PDFs
- Easy to sign agreements, proposals, NDAs, or invoices
- Ideal for professionals managing multiple documents
No matter the device, every signature is linked to a unique signer ID, helping verify identity and prevent fraud.
Do I need to install an app to sign a PDF?
No, you can sign directly from your browser on any device.
Can I send PDFs for others to sign?
Yes. Invite signers by email, even if they use different devices.
Do signers need an account?
Yes, they confirm their email and sign in to verify identity.
Is signing a PDF secure?
Yes. SignBox stores your signed PDFs securely and links each signature to a unique signer ID.
Sign PDFs Easily from Any Device
Upload → Sign → Download.
Fast, secure, and compatible with iPhone, Android, Mac, and Windows.
Sign your PDFs the smart way with SignBox.
Can I Store or Download Signed Documents Safely?
Yes, you can safely store and download signed documents when using a secure e-signature platform. After a document is signed, you need a reliable place to keep it protected, organized, and easy to access whenever you need it. Whether you're signing contracts, NDAs,...
How Do I Verify an Electronic Signature?
Verifying an electronic signature ensures that a document was truly signed by the intended person and hasn’t been changed afterward. With digital transactions becoming the new normal, this verification step protects both you and your clients by ensuring authenticity...
Can I Create Templates for Frequently Used Contracts?
Yes. If you regularly send the same agreements, like NDAs, project proposals, invoices, onboarding forms, or service contracts, creating templates helps you save time and ensure consistency. Instead of uploading and preparing the same document again and again, you can...