A reference manager is the one tool where the decision you make in week two of your dissertation still matters in the final week — migrating a half-built library mid-project is miserable, so it is worth choosing properly once. Here is the comparison first, then the verdict.
| Zotero | Mendeley | EndNote | |
|---|---|---|---|
| Maker | Digital Scholar (non-profit) | Elsevier | Clarivate |
| Price | Free; paid file storage optional | Free | Paid (EndNote 2025); many universities hold site licences |
| Included online storage | 300 MB free; 2 GB at $20/yr, 6 GB at $60/yr, unlimited at $120/yr | 2 GB free | Depends on licence; campus versions common |
| Word processor support | Word, LibreOffice, Google Docs | Word (Mendeley Cite add-in) | Word (Cite While You Write) |
| Citation styles | Thousands via CSL, including many university Harvard variants and OSCOLA | CSL styles, large library | Very large style collection, strong in sciences |
| Browser capture | Excellent (Zotero Connector) | Good (Web Importer) | Adequate |
| Best suited to | Most students, any discipline | Students already in the Elsevier ecosystem | Departments that mandate it or provide it |
The shortlist, ranked
1. Zotero — the default choice
Zotero is free, open-source, and maintained by Digital Scholar, a non-profit — which matters because its incentives are aligned with keeping your library yours. The browser connector saves a reference, its PDF and a snapshot in one click; the word processor plug-ins insert citations and rebuild the bibliography live; and the style repository covers thousands of variants, which is decisive in the UK where “Harvard” means something slightly different at every institution — pick your university’s own variant rather than generic Harvard where one exists. Law students get OSCOLA support too, with the caveats in our OSCOLA guide about matching the edition your school marks against.
The only real limit is file storage: the free 300 MB holds a modest PDF library, after which syncing files costs $20 a year for 2 GB — or nothing, if you sync PDFs via your university OneDrive and let Zotero sync only the metadata. Where it falls short: the interface is functional rather than pretty, and group libraries draw on the owner’s storage quota.
2. Mendeley — fine, with eyes open
Mendeley Reference Manager is free with 2 GB of storage — the most generous free file tier of the three — and its Word add-in is perfectly capable. It suits students already living in Elsevier’s ecosystem. Where it falls short: it is a closed platform owned by a publisher, the desktop app has been through years of consolidation that retired features long-time users relied on, and exporting a heavily annotated library is not as clean as Zotero’s. If you start here, keep an exported backup of your library as a habit.
3. EndNote — when your department provides it
EndNote 2025, from Clarivate, is the establishment option: extremely capable at scale, strong in the sciences, and the tool many supervisors themselves use. It is also the only paid product on this list, and Clarivate does not even publish a simple price on the product page — pricing runs through its store and campus agreements. The practical rule for an undergraduate: use EndNote if your university’s site licence gives it to you free and your department supports it; do not buy it personally for a single dissertation when Zotero exists. Where it falls short: cost, and a heavier learning curve than either rival.
The recommendation
Use Zotero unless your department hands you EndNote and expects it. It is free where free matters (references, sync of metadata, unlimited devices), the storage upsell is cheap and avoidable, and it is the least likely of the three to strand your library behind a corporate decision. Choose Mendeley only if its 2 GB free file storage is genuinely the deciding factor and you keep backups.
Why the old comparisons you will find elsewhere mislead
Reference-manager advice ages badly, and much of what ranks in search predates three changes that alter the calculus. Ownership moved: Mendeley has been Elsevier’s since 2013, and EndNote sits inside Clarivate’s analytics business, so both tools now serve corporate strategies bigger than your bibliography. Products consolidated: the Mendeley desktop application that older guides praise was wound down in favour of the leaner Reference Manager, which is precisely why “feature X” from a 2019 review may simply no longer exist. And the free tier logic shifted: EndNote now leans on a web version alongside the desktop product, while Zotero’s model — everything free except bulk file sync — has stayed stable for years, which is itself a point in its favour. Whenever a comparison names a feature that decides your choice, verify it against the tool’s current pages rather than the review’s screenshots.
Set-up in twenty minutes, whichever you choose
Install the desktop app and the browser connector or importer; install the word processor plug-in and insert one test citation into a scratch document; set the citation style to your department’s exact variant, not a lookalike; create one collection or folder per dissertation chapter; and save your first five real sources from the library catalogue, checking that authors, dates and titles imported cleanly. Twenty minutes now surfaces every configuration problem while it is still trivial — the same errand run in submission week is a crisis.
Three habits that matter more than the tool
First, capture at the moment of reading — a reference manager only saves time if entries go in when you first meet the source, not in a panicked import the week before submission. Our guide to running an honest AI-assisted literature review pairs naturally with this: the manager holds the sources, the synthesis stays yours.
Second, check every generated citation against your department’s style guide once, early. Generated bibliographies inherit the errors of their metadata — publisher pages routinely mis-capitalise titles or omit place of publication, and no manager fixes that for you. Ten minutes of spot-checking in week three beats a bibliography rebuild in the deadline week.
Third, know what your bibliography is for before you pad it. Markers read reference lists as evidence of the reading behind the argument, and inclusion rules differ by department — some count citations inside the text toward the word limit, as we found when we compiled dissertation word-count rules across UK universities. A hundred entries you never cite convince nobody.
If the bibliography is under control and the chapters themselves are the problem, Tesify can structure and draft your dissertation with you — including an automatic bibliography that follows your citation style — 100% written by you.
Frequently asked questions
Is Zotero completely free?
The software, unlimited references, and metadata sync are free. Only synced file storage beyond 300 MB costs money — 2 GB is $20 a year — and you can avoid even that by storing PDFs elsewhere and syncing references only.
Is Mendeley still free after the Elsevier acquisition?
Yes. Mendeley Reference Manager is free and includes 2 GB of document storage. It has been an Elsevier product since 2013, which is a governance consideration rather than a price one.
How much does EndNote cost for a student?
Clarivate sells EndNote 2025 through its online store and institutional agreements rather than publishing one headline price; student pricing exists but varies by seller. Check whether your university’s site licence already covers you before spending anything — many UK universities’ licences do.
Which reference manager is best for Harvard referencing?
All three handle Harvard, but “Harvard” is a family of departmental variants, not one style. Zotero’s community style repository has the broadest coverage of specific university variants — search for your institution’s name and use its exact style where available, falling back on Cite Them Right Harvard otherwise.
Can I switch reference managers mid-dissertation?
Yes — all three export and import RIS or BibTeX — but expect to lose annotations, folder structures and some metadata cleanliness in the move. Switch early if you must switch; after the literature review is written, live with your choice.
Do these tools work with Google Docs?
Zotero has proper Google Docs integration through its Connector. Mendeley and EndNote are strongest in Word. If you draft in Docs, that alone decides it.
Will a reference manager format my footnotes for OSCOLA?
Zotero has an OSCOLA style and handles footnote-based citation; it remains your job to check the output against the OSCOLA edition your law school marks to, especially pinpoints and repeat citations. See our full OSCOLA guide for the fifth-edition changes.
Is 300 MB of Zotero storage enough for a dissertation?
For references alone, easily — metadata is tiny. It fills up only if you sync full-text PDFs. A typical undergraduate library of a few hundred PDFs fits in the 2 GB tier, or costs nothing if you keep PDFs in university cloud storage instead.
Do I still need to proofread a generated bibliography?
Yes. Generated entries inherit whatever errors the source metadata carried — capitalisation, missing editions, wrong dates. One careful pass against your style guide is non-negotiable before submission.
Which tool do universities actually support?
Most UK university libraries run training for at least Zotero and EndNote, and many maintain a comparison page of their own. If your library offers a workshop for one of them, that support is worth something when the Word plug-in misbehaves at 11pm.