Systematic Review Tools Compared: Covidence, Rayyan, EPPI-Reviewer, and Zotero Workflows

Overview

Systematic review tools sit at the intersection of research discovery, project management, and reproducible documentation. A team may begin by searching academic journals, peer reviewed journals, and other literature review sources across databases, then quickly run into a familiar set of problems: duplicate records, inconsistent decisions across reviewers, missing full texts, confusing exports, and uncertainty about how to document the process for publication.

That is where review screening software becomes useful. Covidence, Rayyan, and EPPI-Reviewer are purpose-built platforms for evidence synthesis. Zotero is different: it is primarily a reference manager, but it often plays a central role in literature review workflow tools because it can collect research articles, organize PDFs, attach notes, manage citations, and support exports into downstream screening tools.

In broad terms, the tools tend to fall into four roles:

• Covidence: streamlined review management with a clear, guided workflow for screening and downstream review steps.
• Rayyan: fast, accessible screening support, especially useful for title and abstract decisions and quick team collaboration.
• EPPI-Reviewer: more configurable evidence synthesis software suited to complex or methodologically diverse reviews.
• Zotero: the reference backbone for collecting, cleaning, tagging, and citing scholarly articles before and after formal screening.

If your main question is “Covidence vs Rayyan,” the short answer is that Covidence usually appeals to teams that want a more structured end-to-end workflow, while Rayyan is often attractive for teams prioritizing quick screening setup and lower-friction collaboration. EPPI-Reviewer becomes more relevant as review complexity increases. Zotero remains valuable even if you adopt one of the others, because citation control and library organization rarely disappear from the process.

One useful grounding point comes from the review literature itself. Systematic and scoping reviews often combine multiple methods of synthesis, varied inclusion criteria, and iterative refinement of categories. The source material provided for this article, while not about software, shows that review work can involve narrative synthesis, vote counting, and careful delimitation of scope. That matters because tools should support methodological clarity rather than force a rigid process that does not fit the review design.

How to compare options

A useful comparison starts with your protocol, not with a feature list. Before selecting a platform, answer five practical questions.

1. What type of review are you doing?

A narrowly defined intervention review with clear inclusion criteria may work well in a streamlined platform. A scoping review, mixed-method review, or project with iterative coding may benefit from a tool that offers more customization. If your methods may evolve as the team learns from the literature, flexibility matters.

2. How large is the search result set?

A small graduate thesis review can tolerate more manual cleanup. A large multi-database search with thousands of records cannot. In that case, import stability, deduplication, and bulk decision management become central evaluation criteria.

3. How many reviewers need to collaborate?

Solo reviewers can work with almost any combination of tools. Dual independent screening, adjudication, and librarian support require clearer permission settings, conflict resolution workflows, and consistent exports. The more people involved, the more important interface clarity becomes.

4. What documentation will you need for publication?

Most review teams eventually need to report record counts, screening decisions, reasons for exclusion, and a reproducible path from search to included studies. A tool that saves time early but creates reporting friction later can be a poor trade.

5. Where will references live long term?

Screening software helps with decisions, but your citation library often needs a more permanent home. Zotero is especially useful here because it supports ongoing literature management, note-taking, citation generation, and manuscript writing after the review is complete.

When comparing systematic review tools, use these criteria rather than marketing labels:

• Import quality: Can it ingest records cleanly from common databases and journal finder workflows?
• Deduplication: Does it identify likely duplicates accurately enough to reduce manual review without creating risk?
• Screening speed: Are title and abstract decisions quick and easy to apply at scale?
• Blinding and conflict handling: Can independent reviewers work without influencing each other, then reconcile decisions clearly?
• Full-text management: Can you track PDFs, exclusion reasons, and article status without workarounds?
• Extraction and coding: Does the platform support the level of detail your synthesis needs?
• Export and portability: Can you move data out in usable formats if your team changes tools?
• Learning curve: Will the team actually use the system consistently?

That last criterion is easy to underestimate. A simpler tool used well is often better than a richer tool used inconsistently.

Feature-by-feature breakdown

This section compares the four options by workflow stage rather than by brand.

Importing references and building the initial library

Zotero is the natural starting point for many teams because it is built for collecting and organizing references from databases, websites, and PDFs. It is especially helpful when your search spans academic journals, open access journals, repositories, and grey literature. Tags, collections, saved searches, and notes help create a clean staging area before screening begins.

Covidence and Rayyan are more focused on importing records for review decisions than on long-term library management. They are strong once you already have the citations. EPPI-Reviewer can also function as a central environment, but many teams still prepare references externally first to keep the imported dataset tidy.

Best fit: Use Zotero if your challenge is collecting and organizing diverse literature review sources before the formal review pipeline starts.

Deduplication

Deduplication is often the first point where teams discover the difference between a reference manager and dedicated review software. Zotero can help identify duplicates within a library and gives users direct control over merged records. That control is useful, but manual oversight can take time in large projects.

Covidence is commonly chosen by teams that want duplicate handling integrated into the review workflow. Rayyan also supports record cleanup and screening preparation, though teams may vary in how much they trust automated matching versus manual review. EPPI-Reviewer is typically more appealing when the dataset is large and the review design is complex enough that careful preprocessing is worth extra setup.

Best fit: For smaller reviews, Zotero-first deduplication may be enough. For larger teams or higher-volume screening, dedicated review software usually reduces friction.

Title and abstract screening

This is where Rayyan has built much of its reputation. It is well suited to fast screening, clear include/exclude decisions, and collaborative review. Teams that want to start screening quickly often find it approachable.

Covidence is also strong here, especially for teams that want a more guided process that carries forward into later stages. Its advantage is not just screening speed but continuity into full-text review and subsequent steps.

EPPI-Reviewer can handle screening, but its strengths are more apparent when your team needs deeper configuration or more elaborate coding structures. Zotero can support a lightweight manual screening workflow through tags and saved searches, but it is rarely the best standalone solution for blinded dual screening.

Best fit: Choose Rayyan for quick, focused screening; choose Covidence if screening is one part of a broader managed workflow.

Full-text review and exclusion reasons

Covidence tends to stand out when teams need a straightforward path from abstract screening to full-text review, including reason-for-exclusion tracking. This matters for transparent methods reporting.

Rayyan can support later-stage decisions, but some teams may find that its main appeal remains early screening rather than full review management. EPPI-Reviewer is appropriate when full-text decisions involve more nuanced coding or multiple layers of eligibility logic.

Zotero is still useful here as the PDF repository and note-taking space, especially when you want your full-text files and annotations preserved outside a proprietary review environment.

Data extraction, coding, and synthesis support

This is the area where differences become sharper. Covidence supports structured review steps and can suit teams with fairly standard extraction needs. EPPI-Reviewer becomes more attractive when extraction fields, coding frameworks, or synthesis pathways need to be customized more extensively.

Rayyan is generally less likely to be chosen as the center of a highly detailed extraction workflow. Zotero, while not an extraction platform in the formal sense, remains helpful for storing article notes, attaching supplementary files, and preserving reading context.

Best fit: If your extraction plan is simple and standardized, Covidence may be sufficient. If your methods are more complex, EPPI-Reviewer deserves close consideration.

Collaboration and audit trail

Covidence and Rayyan both serve collaborative teams, but they do so with different emphases. Rayyan often feels lighter and faster to adopt. Covidence often feels more process-driven. EPPI-Reviewer can support complex team structures, though the tradeoff may be more training and setup.

Zotero adds collaboration through shared libraries, group organization, and citation consistency. It does not replace a full audit trail for formal screening decisions, but it complements one well.

Writing and citation management

This is where Zotero clearly leads the group. Once the review moves into manuscript drafting, the need for reliable citation support becomes central. A citation generator alone is rarely enough for a serious review project; teams usually need stable reference data, attachment storage, notes, and citation insertion into drafts. Zotero fills that gap elegantly.

For researchers also comparing broader tools for academics, this is an important distinction: screening software helps decide what to include, while a reference manager helps carry the included studies into writing, revision, and future reuse.

Best fit by scenario

If you are deciding among these tools, it helps to match them to realistic research contexts.

Best for a small student-led review: Zotero plus Rayyan

If the project is a thesis, capstone, or first review, this pairing is often practical. Zotero manages search results, PDFs, and citations. Rayyan handles title and abstract screening with less setup burden. This combination keeps costs and complexity relatively contained while still supporting a defensible workflow.

Best for a health sciences or policy team needing a guided path: Covidence

When multiple reviewers need to move cleanly from import to screening to full-text decisions and structured extraction, Covidence often fits well. Teams that value process clarity over deep customization may prefer it.

Best for complex mixed-method or highly coded reviews: EPPI-Reviewer

If your protocol includes layered coding, complex inclusion logic, or iterative synthesis structures, EPPI-Reviewer is often the most suitable of the four. It asks more from users, but that added complexity can be justified when the review design is correspondingly demanding.

Best for long-term reference control across projects: Zotero

Even if you use another platform for screening, Zotero remains one of the most useful anchors in a research workflow. It supports future article discovery, teaching materials, writing projects, and citation reuse well beyond a single review.

Best if your team expects to switch tools later: Zotero-centered workflow

Portability matters. Keeping a well-maintained master library in Zotero reduces dependence on any single screening platform. If a team later moves from Rayyan to Covidence, or from a manual process to EPPI-Reviewer, a disciplined central library makes migration easier.

For librarians supporting multiple departments, this may be the safest evergreen recommendation: standardize the citation library first, then choose the screening layer according to project complexity.

When to revisit

This comparison is worth revisiting whenever any of the following changes occur: platform pricing shifts, collaboration limits change, export formats evolve, new AI-assisted features appear, or your institution adopts a new preferred workflow. Tool selection should also be reconsidered when your review type changes. A process that worked for a scoping review may not be ideal for a tightly protocolized systematic review, and vice versa.

Revisit your setup if you notice any of these warning signs:

• Your team is spending more time cleaning records than screening them.
• Reviewers are confused about where the authoritative version of a citation lives.
• Exclusion reasons are inconsistent or hard to export.
• PDF storage and annotations are scattered across personal folders.
• The manuscript phase reveals citation problems that could have been solved earlier.

A simple annual review checklist can keep your workflow current:

1. Confirm whether your current tool still supports your review design.
2. Test import and export with a small sample from your main databases.
3. Check whether deduplication rules still match your search sources.
4. Review where PDFs, notes, and final citations are stored.
5. Decide whether your team needs more structure, more flexibility, or lower overhead.

If you are building a research methods toolkit more broadly, it can also help to connect review workflows with adjacent academic support practices such as writing, course design, and evidence use in teaching. For example, instructors thinking about how to turn literature into classroom practice may find related guidance in Authenticating Difficult Pasts: Archives, Ethics, and Classroom Strategies for Teaching Slavery’s Legacies and Teaching the Contemporary Novel: Using Ben Lerner’s Transcription to Explore Form, Authorship, and Ethics. Those pieces are not about review software, but they reflect the same core principle: research workflows work best when evidence management and downstream use are planned together.

The practical takeaway is straightforward. Start by deciding where your references will live, then choose the screening layer that matches your review’s scale and complexity. Use Zotero when you need durable citation and PDF management. Use Rayyan when fast screening is the priority. Use Covidence when you want a smoother managed path across review stages. Use EPPI-Reviewer when methodological complexity justifies a more configurable environment. And revisit the decision whenever your team, protocol, or tool landscape changes.