A clear format boundary is part of a good reading product. Here is what works now, what does not, and which open formats belong to the longer-term direction.
Currently supported
Public PDF URLs
Paste an HTTP or HTTPS link to a PDF that is publicly fetchable. Paper opens the document from the link instead of asking you to create an account or build a library.
Selectable text
The PDF needs a real text layer. Paper can reflow text-heavy books, essays, papers, and reports; scanned image-only PDFs are not OCR'd in the current version.
Up to 30 MB
The current fetcher caps PDFs at 30 MB. This keeps the URL-to-reader path predictable while the product is focused on reading quality.
Reading, not page fidelity
Paper preserves the words and useful hierarchy as a reading view. Keep the original PDF for forms, precise page layout, complex figures, or anything where visual placement is the point.
Future directions
These are areas Paper may explore, not formats supported today and not promises about a release date.
Public-domain books
Standard books from open collections such as Project Gutenberg are a natural extension of the reading-layer idea, especially when a clean book view is available.
EPUB and open ebooks
An open ebook format could fit Paper's typography-first approach, provided import, licensing, and source attribution remain clear.
Long web pages
Essays and documentation already live on the public web. A future reader could make them as calm to read as a reflowed document without copying the web's surrounding noise.
More document types
Other public, text-first formats may follow when Paper can support their structure honestly instead of flattening everything into an unreliable stream.
Want to try the format Paper supports now?
Read a PDF onlineStart with the first source.
Paper's broader promise begins with a public PDF link and a better place to read it.
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