Canto PDF

Canto PDF is a local-first PDF workspace for organizing documents and completing everyday PDF tasks. Import PDFs, create new documents, process copies, protect files, and share only when you choose.

Key features:
- Import one or more PDF files with the Android document picker.
- Create blank PDFs or turn selected images into a PDF.
- Merge selected PDFs or split a document after the page you choose.
- Optimize image-heavy PDFs and create password-protected copies.
- Decrypt protected copies when you provide the password.
- Add watermarks and page numbers to processed copies.
- Add a visible signature stamp with a name or initials.
- Fill supported standard AcroForm fields with a value.
- Crop pages with a configurable inset or rotate them by 90, 180, or 270 degrees.
- Run OCR on an image and create a text-based PDF with wrapped, paginated output.
- Search across file names, folders, and tags.
- Organize documents with folders and tags, and mark files as read, favorite, or important.
- Open PDFs in a compatible Android viewer or share a PDF through the system share sheet.

Canto PDF works offline and does not require an account, subscription, contacts, camera access, or broad storage access. Imported and created documents stay in app-private storage unless you explicitly open or share them. PDF processing happens on the device.

The app uses the Android document and image pickers for user-selected files. It does not scan shared storage in the background. Processing creates a new copy whenever possible, so your original document remains available for review.

Privacy and permissions:
Canto PDF uses Android's system document and image pickers instead of broad storage access. The app does not require camera or contacts permissions. Imported and created PDFs remain in app-private storage unless you explicitly open or share a document with another app.

The Sign tool adds a visible signature stamp; it is not a certificate-based digital signature. Form filling targets supported standard AcroForm fields. OCR is provided for English and other Latin-script text through the bundled on-device recognizer.