Overview

Zotero is an open-source research manager that brings references, reading, notes, citations, and shared libraries together. It is strongest for researchers who want control over a substantial reference collection without paying for the core software. The free storage allowance is modest, so large synced file libraries may call for a paid plan.

Its browser Connector captures research items as you browse, while collections, keyword tags, and saved searches help keep a library usable as it grows. Zotero also includes a PDF reader and note editor, linking collection and reading tasks with citation tools for common writing applications. It is developed for researchers and cultural heritage institutions by a global community, and sits within Citation Management Software and Reference Management Software.

Key features

Capture and organization: The Connector can detect research items on web pages and save them. Collections, tags, and saved searches offer useful ways to group and retrieve material rather than relying on a single folder structure.
PDFs and notes: A built-in PDF reader, note editor, and PDF annotation support keep reading work alongside references. This makes Zotero a practical choice for managing research materials, not just formatting bibliographies.
Citations: More than 9,000 citation styles and integrations with Microsoft Word, LibreOffice, and Google Docs make Zotero adaptable to different publication requirements and writing workflows.
Sync and collaboration: Optional Zotero Storage synchronizes PDFs, images, web snapshots, and other files across devices and provides online-library access. Libraries can be shared with any number of people at no cost, and groups support shared collections—useful for collaboration without a per-member sharing cap.
Import and API: Zotero accepts a broad range of reference formats, including BibTeX, RIS, EndNote XML, MARC, and PubMed XML. Its Web API supports integrations and development; version 3 is the recommended default for new projects.
Privacy and hosting: The desktop app stores research locally by default, and syncing is optional. Data sent to Zotero servers 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 that self-hosting is technically challenging and does not support those installations.

Pricing

Zotero is freemium: the core tool is free, with paid plans primarily increasing synced storage. The free plan includes 300 MB for $0.00 USD per free. That can suit a reference-focused library or users who keep most files local, but may be restrictive for people syncing many PDFs and snapshots.

300 MB — $0.00 USD per free: A sensible starting point for basic storage needs, with no paid commitment.
2 GB — $20.00 USD per year: The lowest paid tier, billed at $20/year (equal to $1.67 per month). It offers more room for synced files without the higher annual cost of larger tiers.
6 GB — $60.00 USD per year: Billed at $60/year (equal to $5 per month), this suits a larger file collection that has outgrown the entry tier.
Unlimited — $120.00 USD per year: Billed at $120/year (equal to $10 per month), it removes the stated storage ceiling for users with extensive synced libraries.

Choosing a smaller tier means accepting its storage cap; users can keep Zotero’s desktop library local and syncing optional, but need sufficient paid storage if they want a larger collection of files synchronized and accessible online.

Platforms

Zotero supports Android, iOS, Linux, macOS, and Windows, alongside web access, a browser extension, an API, and self-hosting. The breadth suits mixed-device research workflows, though self-hosting requires technical effort and is not supported by Zotero.

Who it's for

Zotero is a strong fit for students, academics, and other researchers who need to collect sources, annotate PDFs, manage citations, and share libraries. Its free core, wide citation-style support, and no-cost sharing make it particularly compelling for individuals and collaborative groups mindful of software costs. Readers who need substantial synchronized file storage should budget for a paid plan; those unwilling to rely on a public support forum or manage a storage cap may prefer another fit.

Pros and cons

Pro: A capable research workflow is available without a core-software charge, and the free plan includes 300 MB of storage.
Pro: Over 9,000 citation styles and support for three major writing applications accommodate varied academic writing needs.
Pro: Sharing has no stated people limit and costs nothing, making group libraries accessible to large collaborations.
Pro: Local-by-default storage and optional syncing give users a choice about whether to place research files on Zotero's servers.
Con: The free storage cap is only 300 MB, so users who sync many PDFs or snapshots may need a paid tier.
Con: Running the open-source data server locally can be technically challenging, and Zotero does not support self-hosted installations.
Con: Most support takes place in public Zotero Forums, which may not suit users who expect a private support channel.

Alternatives

For a guided comparison across the category, browse Citation Management Software or Reference Management Software.

Lean Library Workspace is worth considering if a free plan with up to three projects and three invitations per shared project fits better; its free basic plan excludes article and smart citation suggestions.
Sciwand may suit readers who want core reading, organizing, and writing tools free, with AI free for seven days; its free plan is available across iOS, Linux, macOS, and Windows.
Mendeley Reference Manager offers a free plan with 2 GB of storage and five Reading Assistant questions, a larger free storage allowance than Zotero.
EndNote is an option for readers considering an upgrade license offered as a one-time purchase at $94.00 USD per once.
Logically may appeal to readers seeking AI-focused tools, with its free plan capped at 100 MB of reference and file storage and daily AI allowances.
Qiqqa is another freemium option with Android, self-hosted, web, and Windows platforms.
ReadCube Papers is a paid alternative with no free plan; its Essentials tier is $10.00 USD per month for one user and five shared libraries.
RefWorks offers an institutional subscription, typically purchased by an institution or library for students, with custom pricing.

Verdict

Choose Zotero if you want an open-source research manager that combines source capture, organization, PDF annotation, citations, and flexible sharing without charging for the core tool. Its principal trade-off is limited free synced storage: readers with large file libraries should plan for a paid tier, while those seeking institution-provided service or a different support model should compare alternatives.

	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