Overview

Zotero is a reference manager for building a research library from web sources, PDFs, and other materials. It suits researchers who want capture, reading, organization, and citations in one open-source tool. Its strongest case is a flexible library and broad citation support; its main trade-off is that storing files across devices can require a paid plan.

The desktop app keeps research locally by default, with syncing optional. Zotero also fits the Citation Management Software and Reference Management Software categories.

Key features

Browser capture: The Zotero Connector recognizes research items as you browse and saves them to your library, reducing the work of collecting sources manually.
Library organization: Collections, keyword tags, and saved searches offer useful ways to group and retrieve material as a library grows.
PDF reading and annotation: A built-in PDF reader and note editor keep reading and note-taking alongside references.
Citations: Support for over 9,000 citation styles and integration with Microsoft Word, LibreOffice, and Google Docs make Zotero a strong fit for varied academic writing requirements.
Sync and online access: Optional Zotero Storage syncs PDFs, images, web snapshots, and other files across devices and makes them accessible through the online library. The free tier's 300 MB can be restrictive for people who keep many files with their references.
Sharing and groups: A library can be shared with any number of people at no cost, and groups support shared collections. That makes collaboration possible without buying seats.
Privacy and self-hosting: Desktop data stays local unless syncing is enabled. Data sent to Zotero is encrypted in transit; data for newly created accounts is encrypted at rest with AES-256. Server data is stored in AWS us-east-1 in the United States. The open-source data server can be run locally, but Zotero warns this is technically challenging and does not support such installations.
API and imports: The Web API defaults to version 3, recommended for new development. Zotero supports a wide range of import formats, including BibTeX, RIS, EndNote XML, MARC, MEDLINE/nbib, and Zotero RDF.

Pricing

Zotero is freemium. The free plan includes 300 MB of storage, and library sharing has no per-person charge. Storage plans add room for synced files; choose based on how much material you need available across devices.

300 MB: 0.00 USD per free (billed Free). Best for users whose synced files fit within the cap; larger libraries may need to store files elsewhere or upgrade.
2 GB: 20.00 USD per year (billed $20/year (equal to $1.67 per month)). A modest step up for users who need more than the free allowance without paying for a large archive.
6 GB: 60.00 USD per year (billed $60/year (equal to $5 per month)). Suits users with a larger collection of synced PDFs and other files.
Unlimited: 120.00 USD per year (billed $120/year (equal to $10 per month)). The straightforward option for users who do not want to manage a storage quota.

The paid tiers change storage capacity; Zotero's no-cost library sharing is useful for groups regardless of tier. The free plan is less suitable when cross-device access to a sizable file collection is essential.

Platforms

Zotero is available on Android, iOS, Linux, macOS, and Windows, as well as on the web. It also offers a browser extension, an API, and a self-hosted option. The self-hosted server is open source, but running it locally can be technically challenging and is not supported by Zotero.

Who it's for

Zotero is a strong choice for researchers and cultural heritage institutions that need to collect sources, organize a reference library, annotate PDFs, and produce citations in common writing applications. It also suits groups that want shared collections without a per-person library-sharing charge. Readers who need substantial synced file storage should budget for a paid tier; those who require a supported, straightforward self-hosted server should look elsewhere.

Pros and cons

Pro: Over 9,000 citation styles and integrations with Word, LibreOffice, and Google Docs cover a broad range of writing workflows.
Pro: No-cost library sharing for any number of people makes collaboration accessible without seat charges.
Pro: Local-by-default storage and optional syncing give users control over whether research is sent to Zotero's servers.
Con: The free plan's 300 MB storage cap may not cover a large collection of synced PDFs and other files.
Con: Self-hosting is technically challenging and unsupported, so it is not a practical route for everyone seeking server control.
Con: Most support takes place in public Zotero Forums, which may not suit users who want another support channel.

Alternatives

Mendeley Reference Manager is worth considering if its free plan's 2GB storage is a better fit for your file needs; it also includes five Reading Assistant questions.
EndNote may suit users who prefer a one-time purchase: its Upgrade License is 94.00 USD per once, with the offer shown for EndNote 21 or earlier users and EndNote 2025.
Sciwand is another freemium option, with core reading, organizing, and writing tools free and AI free for seven days.
JabRef is a free, open-source alternative for readers who want software with no paid plan.
Lean Library Workspace may fit users who want a free basic plan for up to three projects, with up to three invitations per shared project.
Bookends is an alternative for readers looking for reference-management software on iOS or macOS.
Petal offers a free plan with 1 GB cloud storage, one seat, three guests, and two collections; citation export is not included in that tier.
ReadCube Papers is a paid alternative with a free trial and an Essentials plan priced at 10.00 USD per month.

Verdict

Choose Zotero if you want an open-source research library that links source capture, PDF work, collaboration, and extensive citation support, especially if local storage and optional syncing matter to you. Its no-cost sharing is a clear advantage for groups. Look elsewhere if 300 MB is too little and paid storage does not fit your budget, or if you need a supported self-hosted server.

	KDE Keysmith	Zotero
Free plan	Yes	Yes
Free trial	No	No
Paid from	Free	$1.67/mo
Open source	No	No
Platforms	Linux	Android, api, extension, iOS, Linux, macOS, self-hosted, Web, Windows
Free plan	Yes	Yes
PDF annotation	—	Yes

KDE Keysmith vs Zotero

KDE Keysmith

Zotero