Bookends vs Zotero
Both are bought outright, both sit in documents, and both are bought by people leaving Papers, Paperpile, Mendeley paid storage. Here is what actually differs — including what each price does not buy.
The short answer
- Zotero is free; Bookends costs $74.99.
- Zotero has the cleaner licence: free and open source, against own it, pay for major upgrades for Bookends.
Side by side
 Bookends$74.99Paid upgrades |  ZoteroFreeOpen source | |
|---|---|---|
| What it is | reference manager for macOS you buy once, upgrade when you like | free reference manager with a built-in PDF reader |
| Price | $74.99 | Free |
| Licence | Own it, pay for major upgrades | Free and open source |
| What you get | One payment, and the developer charges for major versions on a stated cadence. | No licence to buy, and the source is public. |
| The catch | Updates stop after two years unless you pay $49.99 for another window; the app keeps working | The app is free forever, but only 300 MB of sync storage is; a PDF library outgrows that fast |
| Macs per licence | not established | not established |
| Account required | no | optional |
| Works offline | yes | partly |
| Apple Silicon | Yes | Yes |
| Free trial | Yes | No |
| On Setapp | No | No |
| Minimum macOS | not established | not established |
| App Store rating | not established | not established |
| Last updated | not established | not established |
| Price checked | 2026-09-22 | 2026-09-22 |
Apple’s public API reports a rating for only a small minority of Mac apps, and returns zero for most of the rest even when the store page plainly shows reviews. A blank here means we could not read a number, never that an app is unrated or disliked.
In their own right
Bookends
A Mac-only reference manager that keeps references and attached PDFs on your own disk, searches PubMed and library catalogues, and formats bibliographies for Word, Pages, Mellel and Scrivener. One payment, two years of updates, and the app keeps working indefinitely after that.
Zotero
Captures citations from the browser with their metadata, stores and annotates the PDFs, and inserts formatted bibliographies into Word, LibreOffice and Google Docs. Open source, run by a non-profit, and free with no paid app tier.