On-device vs cloud PDF editors: why local is better for private files

A cloud PDF editor works by sending your file to a server, editing it there and sending it back. An on-device editor does the same work on your phone. For private documents, that difference is the whole point.

How a cloud PDF editor works

You pick a file, it's uploaded to the provider's servers, the work happens there, and the result is sent back to you. That's a reasonable design for many tasks. It does mean a copy of your document passes through, and is processed on, a computer you don't control, under that provider's storage and retention policies.

How an on-device editor works

The app does the work with your phone's own processor. The document never leaves your iPhone, so there's no upload to wait for, no copy on a server, and nothing to delete later. Sheaf works this way for every tool: editing, filling and signing, conversion, OCR, compression and redaction.

Side by side

• Where your file goes: on-device, it stays on your iPhone. In the cloud, it's uploaded and processed on a server.
• Works without internet: on-device, yes, even in airplane mode. In the cloud, you need a connection, and big files take time to upload.
• Account: Sheaf needs none: download it and start.
• Speed for big scans: on-device, there's no upload or download step.
• What you need to trust: on-device, your own phone. In the cloud, also the provider's storage, retention and security.

When this matters most

Contracts, rental applications, payslips, tax forms, medical letters, invoices with client names, anything with an ID number or a signature on it. These are exactly the files people edit on their phones, and exactly the ones you'd rather not hand to anyone else.

What Sheaf does on your iPhone

Edit text and tables (a longer entry makes the row grow instead of breaking the table), fill and sign forms, convert Word, Excel, PowerPoint and photos to PDF, merge, split, compress and password-protect, with OCR, Redact and Batch in Pro. See all the guides.