Users new to Zotero may find the prospect of importing all their data somewhat daunting. Many researchers already have a large collection of PDFs that they've previously organized manually or using another program. Zotero makes it easy to import these PDFs and retrieve full bibliographic metadata (for searching, citing, indexing, and organizing), taking much of the pain out of switching.

Follow these steps to use the Retrieve Metadata for PDFs function:

1. Drag your existing PDFs into your Zotero library or use the “Store Copy of File” option from the add new item menu (green plus sign).
2. In the middle pane, select the PDFs you want to retrieve metadata for.
3. Right-click on the PDFs and select “Retrieve Metadata for PDFs”.
4. If Zotero can find a match for the item, it will create a full Zotero item with the available data and attach the PDF.
5. If Zotero can't find metadata for an item, you can right-click on it and choose “Create Parent Item” to manually enter the item metadata.

With this feature, there should be no major hurdles to switching to Zotero and taking full advantage of all its powerful search, indexing, organizing, and citation features.

The Retrieve Metadata feature uses several method to locate item metadata. First, it will look for a Digital Object Identifier (DOI) or ISBN number and look these up in their respective registries. If no DOI or ISBN is found, Zotero will query the Google Scholar database for matches to the item text. If Retrieve Metadata is used on dozens of PDFs at a time (particularly for older articles without DOIs), users may be locked out by Google Scholar. If this occurs, Google Scholar will generally restore your access within a few hours. If Google Scholar requests CAPTCHA verification, Zotero will prompt the user.

While this feature can greatly facilitate importing large existing libraries of PDFs, it is not the best way to add items to your library in general. The retrieved metadata, especially from Google Scholar, will be lower quality than if you import using the Zotero Connector plugin in your browser from publisher websites or most scholarly databases. See Getting Stuff into your Library for the best ways to add items to your library.