Concept
Duplicate papers
The same file is never stored twice in your library. Importing it again links the paper you already have, and reusing it costs nothing.
It is easy to download the same paper twice, or to import a folder you partly imported last month. CurTask checks every file you import against your own library first. If the same file is already there, it is not stored again.
What you see
In the import sheet, a file you already have shows Linked existing, with already stored under its size and Reused from your library as its outcome. The top of the sheet counts them, for example 2 duplicates reused · 0 credits.
The paper you already had is used, with everything learned about it: its details, its full text, your tags and notes, and any AI analyses. Nothing is read, stored or analysed again, so a duplicate costs no storage and no credits. See Baggage.
The same happens elsewhere:
- In Discover, papers you already have are marked In your library, and importing one again says it is already in your library.
- In a paper's Connections tab, references you already have are marked in library. See Follow a paper's references and citing papers.
- When you add a PDF to a paper later and that PDF is already in your library, CurTask says This PDF is already in your library. and offers to open that paper.
Adding the same paper to another project
You never need to import a paper again to use it in another project. Add it from your Global Library instead: see Add papers to a project.
What counts as the same
CurTask compares the files themselves, not their names. Two copies of the same file count as the same paper even if you renamed one. Two different files of the same paper (for example, the publisher's PDF and a preprint) are different files, so both are kept.
Only your own library
The duplicate check looks only at your own library. It never compares your files with anyone else's, and no one can find out what is in your library. See Private by default.